Management of the deep carious lesion and the - Ohio State ...
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PRACTICE<br />
restorative dentistry<br />
<strong>Management</strong> <strong>of</strong> <strong>the</strong> <strong>deep</strong> <strong>carious</strong> <strong>lesion</strong><br />
<strong>and</strong> <strong>the</strong> vital pulp dentine complex<br />
D. Ricketts, 1<br />
This article describes <strong>the</strong> relationship between <strong>the</strong> <strong>carious</strong> process<br />
<strong>and</strong> pulp-dentine complex reactions. Where <strong>the</strong> balance between<br />
<strong>the</strong> two is in favour <strong>of</strong> <strong>the</strong> <strong>carious</strong> process <strong>and</strong> where conventional<br />
cavity preparation leads to a direct pulp exposure, <strong>the</strong> direct pulp<br />
cap technique is described. The success <strong>of</strong> <strong>the</strong> technique is<br />
addressed <strong>and</strong> more importantly an alternative technique for caries<br />
removal, namely stepwise excavation, is described which may lead to<br />
a reduced risk <strong>of</strong> <strong>carious</strong> exposure <strong>and</strong> <strong>the</strong> need for <strong>the</strong> direct pulp<br />
cap technique.<br />
Trauma, rapidly progressing caries or<br />
over zealous removal <strong>of</strong> caries can result<br />
in exposure <strong>of</strong> <strong>the</strong> dental pulp. In <strong>the</strong>se situations<br />
a direct pulp capping technique can<br />
be considered in an attempt to preserve <strong>the</strong><br />
vitality <strong>of</strong> <strong>the</strong> pulp <strong>and</strong> to stimulate it to produce<br />
a calcific barrier to wall <strong>of</strong>f <strong>the</strong> exposure.<br />
However, <strong>the</strong> health <strong>of</strong> <strong>the</strong> pulp <strong>and</strong> its<br />
healing capacity will depend on a number <strong>of</strong><br />
factors, including <strong>the</strong> precipitating event<br />
leading to <strong>the</strong> exposure.<br />
Following trauma, when a previously<br />
sound, asymptomatic tooth suffers a coronal<br />
fracture involving <strong>the</strong> pulp, it is widely<br />
accepted that <strong>the</strong> direct pulp cap is <strong>the</strong> treatment<br />
<strong>of</strong> choice, providing <strong>the</strong> exposure is<br />
small <strong>and</strong> is treated within 24 hours. 1,2,3 In<br />
this situation <strong>the</strong> depth <strong>of</strong> damage to <strong>the</strong><br />
pulp tissue is small <strong>and</strong> <strong>the</strong> relatively healthy<br />
pulp tissue has considerable reparative<br />
potential, particularly in young teeth with<br />
immature apices <strong>and</strong> a good blood supply.<br />
However, <strong>the</strong> caries process can lead to<br />
marked changes within <strong>the</strong> pulp-dentine<br />
complex, which can vary considerably<br />
depending on <strong>the</strong> severity <strong>of</strong> <strong>the</strong> disease <strong>and</strong><br />
<strong>the</strong> age <strong>of</strong> <strong>the</strong> pulp. Where <strong>deep</strong> dentine<br />
1 Clinical Lecturer, Unit <strong>of</strong> Comprehensive Restorative<br />
Care, Dundee Dental Hospital, Park Place, Dundee<br />
DD1 4HR<br />
*Correspondence to: David Ricketts<br />
email: d.n.j.ricketts@dundee.ac.uk<br />
REFEREED PAPER<br />
Received 27.02.01; Accepted 16.07.01<br />
© British Dental Journal 2001; 191: 606–610<br />
<strong>lesion</strong>s are concerned it is currently taught<br />
that <strong>the</strong> peripheral aspect <strong>of</strong> <strong>the</strong> cavity<br />
should be rendered completely caries free.<br />
This should be followed by careful excavation<br />
<strong>of</strong> caries at <strong>the</strong> base <strong>of</strong> <strong>the</strong> cavity, overlying<br />
<strong>the</strong> pulp until hard, stained dentine is<br />
reached, 4 thus gradually reducing <strong>the</strong> bacterial<br />
load within <strong>the</strong> cavity. If at final excavation<br />
<strong>the</strong> pulp is exposed, <strong>the</strong> possibility <strong>of</strong> a<br />
direct pulp cap can be evaluated.<br />
In brief<br />
• The direct pulp cap, whilst<br />
predictable for <strong>the</strong> traumatically<br />
exposed pulp, has a questionable long<br />
term prognosis where a <strong>carious</strong><br />
exposure is concerned<br />
The activity <strong>of</strong> a <strong>deep</strong> <strong>carious</strong> <strong>lesion</strong><br />
in dentine can be preferentially<br />
modified, by sealing in <strong>the</strong> dentine<br />
caries. This allows reparative pulpdentine<br />
complex reactions to take<br />
place<br />
When such <strong>lesion</strong>s are re-entered<br />
after six months or more <strong>the</strong> risks <strong>of</strong><br />
directly exposing <strong>the</strong> pulp are<br />
reduced<br />
Whilst <strong>the</strong> literature is replete with studies<br />
on caries <strong>and</strong> endodontic procedures, relatively<br />
little has been published on <strong>the</strong> relationship<br />
between caries <strong>and</strong> <strong>the</strong> vital<br />
pulp-dentine complex. This article <strong>the</strong>refore<br />
aims to review <strong>the</strong> literature on pulpdentine<br />
complex reactions to caries <strong>and</strong> <strong>the</strong><br />
direct pulp capping technique. It will also<br />
aim to address when to place a direct pulp<br />
cap <strong>and</strong> when to undertake root canal treatment,<br />
what materials to use <strong>and</strong> <strong>the</strong> longterm<br />
prognosis <strong>of</strong> such a procedure. More<br />
importantly, an alternative technique <strong>of</strong><br />
caries removal will be discussed which has<br />
been shown to reduce <strong>the</strong> risk <strong>of</strong> pulpal<br />
exposure.<br />
Dental caries <strong>and</strong> <strong>the</strong> pulp dentine<br />
complex reactions<br />
Dental caries in enamel is a subsurface demineralisation<br />
caused by acids produced by<br />
bacteria in <strong>the</strong> surface plaque. These acids<br />
diffuse into <strong>the</strong> tooth structure causing<br />
demineralisation. It is only when <strong>the</strong> relatively<br />
more mineralised surface zone breaks<br />
down that bacteria colonize <strong>the</strong> enamel<br />
<strong>lesion</strong>. At this early stage in <strong>the</strong> <strong>carious</strong><br />
process <strong>the</strong>re is some disagreement as to<br />
when <strong>the</strong> first pulp-dentine complex reactions<br />
occur. Brännström <strong>and</strong> Lind (1965) 5<br />
for example, found an increase in chronic<br />
inflammatory cells beneath <strong>lesion</strong>s apparently<br />
confined to enamel, whereas o<strong>the</strong>rs<br />
report that this only occurs when caries<br />
extends into dentine. 6<br />
At <strong>the</strong> advancing front <strong>of</strong> a dentine <strong>lesion</strong>,<br />
demineralisation also precedes bacterial<br />
invasion. Considerable demineralisation <strong>of</strong><br />
dentine occurs prior to bacterial infection 7<br />
<strong>and</strong> where occlusal <strong>lesion</strong>s are concerned it<br />
is only when <strong>the</strong> caries extends into <strong>the</strong> middle<br />
third <strong>of</strong> dentine <strong>and</strong> is radiographically<br />
visible that significant infection <strong>of</strong> <strong>the</strong> dentine<br />
occurs. 8 Fuzayama investigated <strong>the</strong><br />
relationship between dentine s<strong>of</strong>tening, discolouration<br />
<strong>and</strong> bacterial infection <strong>and</strong><br />
found that s<strong>of</strong>tening preceded discolouration<br />
which in turn preceded bacterial invasion.<br />
9 Thus bacterial acids <strong>and</strong> products,<br />
such as proteases, diffuse ahead <strong>of</strong> <strong>the</strong> bacteria<br />
towards <strong>the</strong> pulp <strong>and</strong> a number <strong>of</strong> factors<br />
influence <strong>the</strong> rate at which this occurs.<br />
These are namely <strong>the</strong> concentration <strong>of</strong> bacterial<br />
by-products, <strong>the</strong> permeability <strong>of</strong> <strong>the</strong><br />
dentine <strong>and</strong> <strong>the</strong> pulpal fluid pressure. 10<br />
The frequency <strong>of</strong> sugar consumption <strong>and</strong><br />
hence acid provoking attacks will affect <strong>the</strong><br />
606 BRITISH DENTAL JOURNAL, VOLUME 191, NO. 11, DECEMBER 8 2001
concentration <strong>of</strong> acid produced in <strong>the</strong> dental<br />
plaque. This in turn will be moderated to<br />
some extent by saliva or whe<strong>the</strong>r <strong>the</strong> <strong>lesion</strong><br />
is open (frank cavitation) or closed, but in<br />
general <strong>the</strong> more acid produced <strong>the</strong> greater<br />
<strong>the</strong> concentration gradient toward <strong>the</strong> pulp.<br />
The permeability <strong>of</strong> <strong>the</strong> dentine, which<br />
resists this inward diffusion <strong>of</strong> acid, changes<br />
with age. Newly erupted teeth are more permeable<br />
<strong>and</strong> less mineralised allowing <strong>the</strong><br />
rapid diffusion <strong>of</strong> acids. As such <strong>the</strong>y may be<br />
more susceptible to rapidly progressing<br />
caries. Pulp dentine complex reactions to<br />
this stimulus are aimed at reducing <strong>the</strong> permeability<br />
<strong>of</strong> <strong>the</strong> dentine. The most common<br />
reaction depends upon a vital odontoblast<br />
process <strong>and</strong> is <strong>the</strong> deposition <strong>of</strong> apatite <strong>and</strong><br />
whitlockite crystals within <strong>the</strong> dentinal<br />
tubules leading to dentine tubule sclerosis.<br />
In addition to this, tertiary dentine may also<br />
be laid down by <strong>the</strong> odontoblast within <strong>the</strong><br />
pulp chamber. 10<br />
If <strong>the</strong> <strong>carious</strong> process proceeds<br />
unchecked, degenerative changes within <strong>the</strong><br />
odontoblasts take place before inflammatory<br />
changes within <strong>the</strong> pulp occur. 11 This<br />
can lead to complete cell death <strong>and</strong> replacement<br />
by odontoprogenitor cells from <strong>the</strong><br />
subjacent cell rich layer. Differentiation <strong>of</strong><br />
<strong>the</strong>se mesenchymal cells into odontoblastlike<br />
cells, can lead to <strong>the</strong> production <strong>of</strong><br />
reparative dentine which, depending on <strong>the</strong><br />
severity <strong>of</strong> <strong>the</strong> <strong>carious</strong> <strong>lesion</strong>, can be irregular<br />
with cellular inclusions or if less aggressive<br />
resemble normal tubular dentine.<br />
Thus <strong>the</strong>re is a fine balance between<br />
<strong>the</strong> speed <strong>of</strong> <strong>the</strong> advancing front <strong>of</strong> <strong>the</strong><br />
dentine <strong>lesion</strong> <strong>and</strong> <strong>the</strong> rate at which<br />
pulp-dentine defenses can be laid down.<br />
These pulp-dentine reactions require a<br />
healthy pulp, however if <strong>the</strong> <strong>carious</strong> process<br />
continues unchecked pulpal inflammation<br />
will ensue. In an attempt to evaluate <strong>the</strong><br />
relationship between <strong>lesion</strong> depth <strong>and</strong> pulpal<br />
inflammation, Reeves <strong>and</strong> Stanley<br />
(1966) showed that if <strong>the</strong> advancing front <strong>of</strong><br />
<strong>the</strong> <strong>lesion</strong> was about 1 mm from <strong>the</strong> pulp<br />
<strong>the</strong>n no significant disturbance occurred. 12<br />
However, once within 0.5 mm <strong>of</strong> <strong>the</strong> pulp<br />
more pathological changes occur, but it was<br />
only when <strong>the</strong> reactionary dentine itself was<br />
involved that ‘pathosis <strong>of</strong> real consequence’<br />
was seen. Shovelton also showed that it was<br />
only when <strong>the</strong> <strong>lesion</strong> was within<br />
0.25 mm–0.3 mm <strong>of</strong> <strong>the</strong> pulp that hyperaemia<br />
<strong>and</strong> pulpitis occurred. 7<br />
Thus in final excavation <strong>of</strong> s<strong>of</strong>t pulpal<br />
caries, if direct perforation <strong>of</strong> <strong>the</strong> pulp occurs<br />
<strong>the</strong> relative rate <strong>of</strong> progression <strong>of</strong> <strong>the</strong> <strong>lesion</strong><br />
has been faster than <strong>the</strong> rate <strong>of</strong> pulp-dentine<br />
reactions. At this stage <strong>the</strong> pulp is likely to be<br />
inflamed <strong>and</strong> <strong>the</strong> decision <strong>of</strong> whe<strong>the</strong>r to place<br />
a direct pulp cap has to be made.<br />
The direct pulp cap.<br />
A direct pulp cap usually involves <strong>the</strong> placement<br />
<strong>of</strong> a calcium hydroxide preparation<br />
directly in contact with an exposed pulp.<br />
For a direct pulp cap to be successful a number<br />
<strong>of</strong> factors have to be met <strong>and</strong> <strong>the</strong>se are<br />
detailed in Table 1. Lin <strong>and</strong> Langl<strong>and</strong> (1981)<br />
have shown that teeth with a history <strong>of</strong> pain<br />
will have an area <strong>of</strong> necrosis within <strong>the</strong> pulp<br />
chamber <strong>and</strong> for many this will extend into<br />
<strong>the</strong> root canal. 13 Bacterial invasion <strong>of</strong> pulp<br />
tissue is closely related to this necrosis <strong>and</strong> as<br />
such <strong>the</strong>se teeth should be endodontically<br />
treated. Teeth exposed during caries<br />
removal will inevitably have some degree <strong>of</strong><br />
inflammation although <strong>the</strong> histological<br />
extent <strong>of</strong> this cannot be accurately predicted<br />
from a clinical examination. Table 1 provides<br />
sensible but not infallible clinical criteria<br />
for successful direct pulp capping.<br />
It was once thought that only pinpoint<br />
exposures could be pulp capped, however<br />
more recent research would suggest that <strong>the</strong><br />
size <strong>of</strong> exposure has no bearing on clinical<br />
outcome. 14,15,16 Whilst <strong>the</strong>se studies pertain<br />
to traumatically exposed pulps, Mejare<br />
<strong>and</strong> Cvek (1993) have suggested that <strong>deep</strong><br />
<strong>carious</strong> exposures be opened up so that<br />
1 mm–3 mm <strong>of</strong> exposed pulp can be<br />
Table 1 Criteria essential for a successful direct pulp cap.<br />
PRACTICE<br />
restorative dentistry<br />
removed. 17 It is important to draw attention<br />
to <strong>the</strong> fact that this study was on young posterior<br />
teeth <strong>and</strong> cannot be regarded as a true<br />
direct pulp cap, but ra<strong>the</strong>r a partial pulpotomy.<br />
This procedure has a number <strong>of</strong><br />
advantages; it reduces <strong>the</strong> potential for<br />
introduction <strong>of</strong> dentine chips into <strong>the</strong> pulp<br />
tissue <strong>and</strong> it enables good contact between<br />
pulp <strong>and</strong> capping agent. It has been shown<br />
that dentine chips inadvertently pushed<br />
into <strong>the</strong> pulp tissue cause severe inflammatory<br />
reaction, which can lead to pulp necrosis.<br />
18,19 It also removes superficially<br />
contaminated pulpal tissue.<br />
It is important to emphasize that whilst<br />
<strong>the</strong> size <strong>of</strong> traumatic exposures is not so<br />
important, <strong>carious</strong> exposures should be<br />
small even if <strong>the</strong>y are opened up fur<strong>the</strong>r at<br />
operation. It is generally agreed that larger<br />
<strong>carious</strong> exposures have a poor prognosis due<br />
to a more severely inflammed pulp, risk <strong>of</strong><br />
necrosis <strong>and</strong> bacterial contamination. 20,21,22<br />
The issue <strong>of</strong> age is also difficult, as <strong>the</strong>re is<br />
no clear cut-<strong>of</strong>f when a direct pulp cap<br />
should no longer be considered. The ageing<br />
process is gradual <strong>and</strong> with increased age <strong>the</strong><br />
pulp tissue becomes more fibrous with a<br />
reduction in pulp volume as a result <strong>of</strong> physiological<br />
secondary dentine formation <strong>and</strong><br />
reactionary dentine due to external stimuli<br />
such as trauma, caries <strong>and</strong> tooth wear. The<br />
blood supply to <strong>the</strong> dental pulp is critical to<br />
its health <strong>and</strong> regenerative capacity, <strong>and</strong> as<br />
this decreases with age so does its capacity to<br />
respond to a direct pulp cap. Hence ra<strong>the</strong>r<br />
than a chronological age as a cut-<strong>of</strong>f, <strong>the</strong> biological<br />
age <strong>of</strong> an individual tooth should be<br />
assessed <strong>and</strong> a previous restorative history<br />
taken into consideration as well as <strong>the</strong> factors<br />
in Table 1.<br />
History Preoperative assessment Clinical findings.<br />
No recurring or Normal vitality tests. Pink pulp<br />
spontaneous pain. Not tender to percussion. Bleed if touched but not<br />
No swelling. No radiographic evidence excessively.<br />
<strong>of</strong> periradicular pathology.<br />
Young patient.<br />
Radiographically obvious<br />
pulp chamber <strong>and</strong> root canal.<br />
BRITISH DENTAL JOURNAL, VOLUME 191, NO. 11, DECEMBER 8 2001 607
PRACTICE<br />
restorative dentistry<br />
Finally <strong>the</strong> location <strong>of</strong> <strong>the</strong> exposure is<br />
important as <strong>the</strong>re should be no pulp tissue<br />
coronal to <strong>the</strong> exposure. Exposure in a cervical<br />
cavity would lead to reactionary dentine<br />
formation which would restrict <strong>the</strong><br />
blood supply to <strong>the</strong> tissue more coronal to<br />
it, leading to necrosis <strong>and</strong> failure. These<br />
teeth should <strong>the</strong>refore be root treated. 23<br />
Calcium hydroxide to date remains <strong>the</strong><br />
material <strong>of</strong> choice for a direct pulp capping<br />
technique in general practice. Its properties<br />
<strong>and</strong> mode <strong>of</strong> action have been comprehensively<br />
reviewed previously. 24 However, a relatively<br />
new material, mineral trioxide<br />
aggregate (MTA) has been investigated. 25 It<br />
consists <strong>of</strong> fine hydrophilic particles, which<br />
when mixed with sterile water results in a<br />
colloidal gel <strong>of</strong> pH 12.5. This gel solidifies to<br />
a hard structure within approximately 4<br />
hours. Once set, it has a high compressive<br />
strength comparable to IRM or Super EBA.<br />
Both laboratory <strong>and</strong> clinical studies have<br />
shown this material to be extremely biocompatable<br />
with pulp tissue <strong>and</strong> to have<br />
good sealing ability against dyes <strong>and</strong> bacteria.<br />
In a limited study, Pitt-Ford et al.,<br />
showed that direct pulpal exposures treated<br />
with MTA demonstrated more predictable<br />
dentine bridge formation than calcium<br />
hydroxide. 26 It would <strong>the</strong>refore appear that<br />
this material may be <strong>the</strong> material <strong>of</strong> choice<br />
for future pulp caps. However, problems<br />
associated with <strong>the</strong> material’s difficult h<strong>and</strong>ling<br />
properties <strong>and</strong> prolonged setting time<br />
may preclude its widespread acceptance<br />
despite its superior <strong>the</strong>rapeutic properties.<br />
What is <strong>the</strong> success rate <strong>of</strong> <strong>the</strong> pulp<br />
cap technique?<br />
The success rate <strong>of</strong> a direct pulp cap is difficult<br />
to establish from <strong>the</strong> dental literature as<br />
studies fail to clearly identify whe<strong>the</strong>r exposures<br />
were due to trauma or caries 27 or<br />
address those resulting from trauma only. 28<br />
Whilst <strong>the</strong> prognosis <strong>of</strong> teeth that have<br />
received direct pulp caps as a result <strong>of</strong><br />
trauma would appear good 28 those with a<br />
<strong>carious</strong> exposure fare less well. 29 In a retrospective<br />
study <strong>of</strong> 123 direct pulp caps on<br />
<strong>carious</strong> exposures only 37% were clearly<br />
successful after 5 years <strong>and</strong> after 10 years<br />
80% had failed. 29 Loss <strong>of</strong> pulp vitality in<br />
<strong>the</strong>se teeth poses a problem as a significant<br />
amount <strong>of</strong> physiological secondary <strong>and</strong><br />
reactionary dentine would have developed<br />
which has <strong>the</strong> potential to complicate subsequent<br />
root canal treatment. In addition <strong>the</strong><br />
root canal system may have become infected<br />
<strong>and</strong> prognosis for root treatment is less<br />
favorable than if vital pulp tissue were<br />
removed. 30 These results question <strong>the</strong> success<br />
<strong>of</strong> <strong>the</strong> direct pulp cap for <strong>carious</strong> exposures.<br />
However, a fur<strong>the</strong>r thorough audit is<br />
required, as only 123 out <strong>of</strong> a possible 401<br />
teeth with a direct pulp cap were available<br />
for 10 year follow up. 29<br />
The indirect pulp cap.<br />
When caries is thought to extend close to,<br />
or into <strong>the</strong> pulp, excavation <strong>of</strong> <strong>the</strong> pulpal<br />
caries can be stopped at stained but firm<br />
dentine. 31 Calcium hydroxide lining is<br />
applied over <strong>the</strong> pulpal dentine prior to<br />
placement <strong>of</strong> <strong>the</strong> definitive restoration.<br />
This is classically referred to as <strong>the</strong> indirect<br />
pulp cap. The difficulty with this technique<br />
is knowing how rapid <strong>the</strong> <strong>carious</strong> process<br />
has been, how much tertiary dentine has<br />
been formed <strong>and</strong> knowing exactly when to<br />
stop excavating to avoid pulp exposure.<br />
Using a stepwise approach to caries<br />
removal <strong>the</strong>se parameters can be regulated<br />
with a more predictable outcome.<br />
Stepwise excavation.<br />
It could be argued that in <strong>the</strong> absence <strong>of</strong> any<br />
signs <strong>and</strong> symptoms <strong>of</strong> pulpitis, <strong>and</strong> where<br />
<strong>the</strong> criteria in Table 1 are met, it is over-judicious<br />
removal <strong>of</strong> caries that leads to a pulpal<br />
exposure. In <strong>the</strong> majority <strong>of</strong> cases this can be<br />
avoided if a stepwise approach to caries<br />
removal is adopted. This approach which is<br />
not completely new, 32 has recently been <strong>the</strong><br />
subject <strong>of</strong> renewed interest. Bjørndal et al.<br />
(1997) 33 investigated 31 teeth with gross<br />
caries, which from a clinical <strong>and</strong> radiographic<br />
examination were thought to have<br />
<strong>carious</strong> pulpal exposures. In <strong>the</strong>se teeth<br />
caries removal was staged over two separate<br />
appointments 6–12 months apart. At <strong>the</strong><br />
first appointment, access to <strong>the</strong> caries was<br />
gained <strong>and</strong> <strong>the</strong> periphery <strong>of</strong> <strong>the</strong> cavity made<br />
completely caries free. S<strong>of</strong>t, wet <strong>and</strong> pale<br />
coloured dentine was left pulpally, which<br />
has previously been shown to be heavily<br />
infected. 34 The cavity was lined with cal-<br />
cium hydroxide <strong>and</strong> restored with glass<br />
ionomer <strong>and</strong> left for 6–12 months.<br />
After this period, cavities were re-entered<br />
<strong>and</strong> <strong>the</strong> dentine in all teeth was found to be<br />
darker in colour, harder <strong>and</strong> drier in consistency.<br />
Microbiological analysis also showed a<br />
significant reduction in cultivable microorganisms<br />
over <strong>the</strong> period in which <strong>the</strong> provisional<br />
restorations were in place. These<br />
findings would imply that by removing some<br />
<strong>of</strong> <strong>the</strong> <strong>carious</strong> biomass <strong>and</strong> sealing <strong>the</strong><br />
remaining caries from extrinsic substrate <strong>and</strong><br />
oral bacteria, <strong>the</strong> caries left behind after <strong>the</strong><br />
first excavation had become less active. This<br />
allows time for pulp-dentine complex reactions<br />
to take place so that at <strong>the</strong> second excavation<br />
visit, <strong>the</strong>re is less likelihood <strong>of</strong> pulpal<br />
exposure. It has also been suggested that by<br />
changing <strong>the</strong> cavity environment from an<br />
active <strong>lesion</strong> into <strong>the</strong> condition <strong>of</strong> a more<br />
slowly progressing <strong>lesion</strong>, this will be accompanied<br />
by more regular tubular tertiary dentine<br />
formation. The success <strong>of</strong> this technique<br />
has been demonstrated in a r<strong>and</strong>omized controlled<br />
study comparing conventional cavity<br />
preparation <strong>of</strong> such <strong>lesion</strong>s with stepwise<br />
excavation. 35 Using <strong>the</strong> stepwise excavation<br />
technique significantly fewer teeth had<br />
exposed pulps (17.5%) compared with conventional<br />
caries removal (40%). These<br />
results were echoed in a similar study <strong>of</strong> <strong>deep</strong><br />
<strong>carious</strong> <strong>lesion</strong>s in primary teeth. 36 In this<br />
study 55 teeth were treated with <strong>the</strong> stepwise<br />
excavation technique <strong>and</strong> 55 control teeth<br />
were prepared conventionally. The proportion<br />
<strong>of</strong> teeth where pulpal exposure occurred<br />
were 15% <strong>and</strong> 53% respectively. The technique<br />
has also been shown to be successful in<br />
a practice-based study 37 where only 5.3% <strong>of</strong><br />
pulps were exposed.<br />
Leaving heavily infected caries, <strong>the</strong><br />
dilemma.<br />
The thought <strong>of</strong> leaving heavily infected <strong>carious</strong><br />
dentine for 6–12 months would seem<br />
contrary to teaching in dental schools. It has<br />
been taught that when a restoration is<br />
placed, <strong>the</strong> presence <strong>and</strong> severity <strong>of</strong> pulpal<br />
inflammation is related to <strong>the</strong> level <strong>of</strong> bacterial<br />
microleakage around <strong>the</strong> restoration.<br />
38–41 Thus it would be logical to think<br />
that leaving dentine caries which is heavily<br />
infected would result in similarly severe pul-<br />
608 BRITISH DENTAL JOURNAL, VOLUME 191, NO. 11, DECEMBER 8 2001
pal inflammation. However, teeth that have<br />
been treated with <strong>the</strong> stepwise excavation<br />
technique do not show any signs or symptoms<br />
<strong>of</strong> pulpitis. The difference here may lie<br />
in <strong>the</strong> fact that in <strong>the</strong> animal studies investigating<br />
<strong>the</strong> effects <strong>of</strong> bacterial microleakage,<br />
cavities have been prepared in sound teeth.<br />
The pulp <strong>the</strong>refore has not had any opportunity<br />
to mount its protective reaction <strong>and</strong><br />
<strong>the</strong> presence <strong>of</strong> bacteria <strong>and</strong> <strong>the</strong>ir by-products<br />
are in contact with dentine whose<br />
tubules are potentially patent <strong>and</strong> pulp vulnerable.<br />
To <strong>the</strong> contrary, <strong>the</strong>re is now a significant<br />
amount <strong>of</strong> evidence to support <strong>the</strong><br />
fact that <strong>the</strong>re are few adverse effects, <strong>and</strong><br />
potential benefits when caries is ‘sealed into’<br />
a tooth. These studies can be divided into<br />
those where caries has been ‘sealed in’ with a<br />
simple fissure sealant <strong>and</strong> those where ultraconservative<br />
caries removal has been<br />
followed by placement <strong>of</strong> a composite<br />
restoration over active caries.<br />
Fissure sealant studies.<br />
When occlusal caries is visible radiographically,<br />
<strong>the</strong> <strong>lesion</strong> extends into <strong>the</strong> middle third<br />
<strong>of</strong> dentine 42 <strong>and</strong> is heavily infected. 8 Studies<br />
have shown that when a fissure sealant is<br />
placed over such <strong>lesion</strong>s <strong>the</strong>re is a significant<br />
reduction in <strong>the</strong> number <strong>of</strong> cultivable<br />
microorganisms. 43–48 Such <strong>lesion</strong>s appear to<br />
arrest <strong>and</strong> no increase in <strong>lesion</strong> size has been<br />
found radiographically over a period <strong>of</strong> two<br />
years. 49 In addition no study has reported<br />
symptoms <strong>of</strong> pulpitis or loss <strong>of</strong> vitality.<br />
Ultraconservative caries removal.<br />
Perhaps some <strong>of</strong> <strong>the</strong> most compelling evidence<br />
is provided by Mertz-Fairhurst et al.,<br />
who in 1998 presented ten year data on 156<br />
ultraconservative, cariostatic sealed restorations.<br />
50 In this study, teeth with clinical <strong>and</strong><br />
radiographic evidence <strong>of</strong> occlusal caries were<br />
minimally prepared by placing a 45°– 60°<br />
bevel in <strong>the</strong> enamel, surrounding a frankly<br />
cavitated <strong>lesion</strong>. The bevel was at least 1 mm<br />
wide <strong>and</strong> placed in sound enamel. No<br />
attempt was made to remove any <strong>carious</strong><br />
dentine <strong>and</strong> <strong>the</strong> resultant ‘cavities’ were<br />
restored with acid etched composites <strong>and</strong><br />
covered with fissure sealant. Although a<br />
number <strong>of</strong> <strong>the</strong>se teeth have been lost from <strong>the</strong><br />
study due to patients failing to return for<br />
recall, 85 have been followed throughout <strong>the</strong><br />
ten years. Various progress reports on <strong>the</strong><br />
study sample have shown that sealing caries<br />
into <strong>the</strong> tooth arrests <strong>the</strong> progress <strong>of</strong> <strong>the</strong><br />
<strong>lesion</strong> by effectively eliminating <strong>the</strong> oral<br />
source <strong>of</strong> substrate to <strong>the</strong> bacteria within <strong>the</strong><br />
<strong>lesion</strong>. 51-55 Only one restoration appeared to<br />
‘cave-in’, only one succumbed to secondary<br />
caries <strong>and</strong> 3.5% showed signs <strong>of</strong> wear. All <strong>the</strong><br />
teeth remained symptomless with no signs <strong>of</strong><br />
pulpal inflammation or necrosis. 50<br />
Why re-enter?<br />
The success <strong>of</strong> this technique is dependent<br />
upon <strong>the</strong> integrity <strong>of</strong> <strong>the</strong> restoration <strong>and</strong> its<br />
seal. Regular recall would be essential. In <strong>the</strong><br />
Mertz-Fairhurst et al. study (1998) <strong>the</strong> regular<br />
recall would identify any lost restoration<br />
at an early stage. However, over <strong>the</strong> ten year<br />
period between 18% <strong>and</strong> 45% <strong>of</strong> patients<br />
failed to attend for annual recall. 50 In <strong>the</strong><br />
unlikely event that <strong>the</strong> restoration should<br />
fail <strong>and</strong> not be detected, <strong>the</strong> potentially reactivated<br />
<strong>lesion</strong> would already be in an<br />
advance stage. Following sealing caries into<br />
<strong>the</strong> tooth, <strong>the</strong> <strong>carious</strong> dentine becomes dry,<br />
harder <strong>and</strong> darker in colour. 33 As a result<br />
<strong>the</strong>re is shrinkage <strong>of</strong> <strong>the</strong> tissue leaving a void<br />
beneath <strong>the</strong> restoration. These two factors<br />
support <strong>the</strong> second stage <strong>of</strong> <strong>the</strong> stepwise<br />
excavation. However, <strong>the</strong> work by Mertz-<br />
Fairhurst et al. (1998) 50 would suggest that<br />
<strong>the</strong> interval between first <strong>and</strong> second excavation<br />
is not critical <strong>and</strong> could be left for<br />
considerably longer than 6–12 months.<br />
Thus use <strong>of</strong> a more conservative technique<br />
for removing caries in a young patient with<br />
very <strong>deep</strong> <strong>lesion</strong>s could eliminate <strong>the</strong> need for<br />
<strong>the</strong> conventional direct pulp cap technique.<br />
In those rare instances when this is still<br />
required, adoption <strong>of</strong> <strong>the</strong> stepwise excavation<br />
technique should result in a minimally<br />
inflamed pulp, superior tertiary dentine formation,<br />
less bacterial load <strong>and</strong> a more predictable<br />
pulp cap. Where this is required <strong>the</strong><br />
use <strong>of</strong> calcium hydroxide, whilst acceptable at<br />
present, may become superceded by a mineral<br />
trioxide aggregate material.<br />
Conclusion<br />
These are exciting times when <strong>the</strong> conventional<br />
wisdom <strong>of</strong> caries removal is being<br />
challenged. 56 This toge<strong>the</strong>r with <strong>the</strong> evolu-<br />
PRACTICE<br />
restorative dentistry<br />
tion <strong>of</strong> new dental materials, dem<strong>and</strong> fur<strong>the</strong>r<br />
research into this subject, particularly<br />
where older more compromised teeth are<br />
concerned.<br />
1 Cox C F, Bergenholtz G, Heys D R, Syed A,<br />
Fitzgerald M, Heys J R. Pulp capping <strong>of</strong><br />
dental pulp mechanically exposed to oral<br />
micr<strong>of</strong>lora: a 1–2 year observation <strong>of</strong> wound<br />
healing in monkey. J Oral Pathol 1985; 14:<br />
156–168.<br />
2 Heidi S, Kerekes K. Delayed direct pulp<br />
capping in permanent incisors <strong>of</strong> monkeys.<br />
Int Endo J 1987; 20: 65–74.<br />
3 Pitt Ford T R, Roberts G J. Immediate <strong>and</strong><br />
delayed direct pulp capping with <strong>the</strong> use <strong>of</strong> a<br />
new visible light-cured calcium hydroxide<br />
preparation. Oral Surg Oral Med Oral Pathol<br />
1991; 71: 338–342.<br />
4 Kidd E A M, Smith B G N. Pickard’s Manual <strong>of</strong><br />
Operative Dentistry. 7th Edition pp 58–59.<br />
Oxford: Oxford University Press; 1996.<br />
5 Brännström M, Lind P O. Pulpal response to<br />
early dental caries. J Dent Res 1965; 44:<br />
1045–1050.<br />
6 Massler M. Pulpal reaction to dentinal caries.<br />
Int Dent J 1967; 17: 441–460.<br />
7 Shovelton D S. A study <strong>of</strong> <strong>deep</strong> <strong>carious</strong> dentine.<br />
Int Dent J 1968; 18: 392–405.<br />
8 Ricketts D N J, Kidd E A M, Beighton D.<br />
Operative <strong>and</strong> microbiological validation <strong>of</strong><br />
visual, radiographic <strong>and</strong> electronic diagnosis <strong>of</strong><br />
occlusal caries in non-cavitated teeth judged to<br />
be in need <strong>of</strong> operative care. Br Dent J 1995;<br />
179: 214-220.<br />
9 Fuzayama T, Okuse K, Hosoda H. Relationship<br />
between hardness, discoloration <strong>and</strong> microbial<br />
invasion in <strong>carious</strong> dentin. J Dent Res 1966; 45:<br />
1033–1046.<br />
10 Kim S, Trowbridge H O. Pulpal reaction to<br />
caries <strong>and</strong> dental procedures. In Cohen S,<br />
Burns R C, Rudolph P. (eds) Pathways <strong>of</strong> <strong>the</strong><br />
pulp. 7th Ed. pp532–534. Missouri: Mosby Inc;<br />
1998.<br />
11 Trowbridge H O. Pathogenesis <strong>of</strong> pulpitis<br />
resulting from dental caries. J Endod 1981; 7:<br />
52–60.<br />
12 Reeves R, Stanley H R. The relationship <strong>of</strong><br />
bacterial penetration <strong>and</strong> pulpal pathosis in<br />
<strong>carious</strong> teeth. Oral Surg 1966; 22: 59–65.<br />
13 Lin L, Langel<strong>and</strong> K. Light <strong>and</strong> electron<br />
microscopic study <strong>of</strong> teeth with <strong>carious</strong> pulp<br />
exposures. Oral Surg 1981; 51: 292–316.<br />
14 Fuks A B, Cosack A, Klein H, Eidelman E.<br />
Partial pulpotomy as a treatment alternative for<br />
exposed pulps in crown-fractured permanent<br />
incisors. Endodont Dent Traumatol 1987; 3:<br />
100–102.<br />
15 Heide S, Kerekes K. Delayed partial<br />
pulpotomy in permanent incisors <strong>of</strong><br />
monkeys. Int Endodont J 1986; 19: 78–89.<br />
16 Klein H, Fuks A, Eidelman E, Chosack A.<br />
Partial pulpotomy following complicated<br />
crown fracture in permanent incisors: a clinical<br />
<strong>and</strong> radiographic study. J Pedodont 1985; 9:<br />
142–147.<br />
BRITISH DENTAL JOURNAL, VOLUME 191, NO. 11, DECEMBER 8 2001 609
PRACTICE<br />
restorative dentistry<br />
17 Mejare I, Cvek M. Partial pulpotomy in young<br />
permanent teeth with <strong>deep</strong> <strong>carious</strong> <strong>lesion</strong>s.<br />
Endodont Dent Traumatol 1993; 9: 238–242.<br />
18 Kalins V, Frisbie H E. Effect <strong>of</strong> dentine<br />
fragments on <strong>the</strong> healing <strong>of</strong> <strong>the</strong> exposed pulp.<br />
Arch Oral Biol 1960; 2: 96 –103.<br />
19 Mjör I A, Dahl E, Cox C F. Healing <strong>of</strong> pulp<br />
exposures: an ultrastructural study. J Oral<br />
Pathol Med 1991; 20: 496–501.<br />
20 Dannenberg J L. Pedodontic-endodontics.<br />
Dent Clin North Am 1974; 18: 367–377.<br />
21 McDonald R E, Avery D R. Treatment <strong>of</strong> <strong>deep</strong><br />
caries, vital pulp exposure, <strong>and</strong> pulpless teeth in<br />
children. In McDonald R E, Avery D R, (eds).<br />
Dentistry for <strong>the</strong> child <strong>and</strong> adolescent. 3rd ed. St<br />
Louis: Mosby, 1978.<br />
22 Seltzer S, Bender I B. Pulp capping <strong>and</strong><br />
pulpotomy. In Seltzer S, Bender I B (eds). The<br />
dental pulp, biologic considerations in dental<br />
procedures. 2nd ed. Philadelphia: Jb Lippincott,<br />
1975.<br />
23 Stanley H R, Lundy T. Dycal <strong>the</strong>rapy for pulp<br />
exposure. Oral Surg Oral Med Oral Pathol.<br />
1972; 34: 818–827.<br />
24 Forman P C, Barnes I E. A review <strong>of</strong> calcium<br />
hydroxide. Int Endod J 1990; 23: 283–297.<br />
25 Torabinejad M, Chivian N. Clinical applications<br />
<strong>of</strong> mineral trioxide aggregate. J Endodon 1999;<br />
25: 197–205.<br />
26 Pitt Ford T R, Torabinejad M, Abedi H R,<br />
Bakl<strong>and</strong> L K, Kariyawasam S P. Using mineral<br />
trioxide aggregate as a pulp-capping material.<br />
J Am Dent Assoc 1996; 127: 1491–1494.<br />
27 Armstrong W P, H<strong>of</strong>fman S. Pulp cap study.<br />
Oral Surg Oral Med Oral Pathol. 1965; 15:<br />
1505–1509.<br />
28 Cvek M. A clinical report on partial pulpotomy<br />
<strong>and</strong> capping with calcium hydroxide in<br />
permanent incisors with complicated crown<br />
fracture. J Endodon 1978; 4: 232-242.<br />
29 Bar<strong>the</strong>l C R, Rosenkranz B, Leuenberg A,<br />
Roulet J-F. Pulp capping <strong>of</strong> <strong>carious</strong> exposures:<br />
treatment outcome after 5 <strong>and</strong> 10 years: a<br />
retrospective study. J Endodon 2000; 26:<br />
525–528.<br />
30 Sjögren U, Hagglund B, Sundqvist G, Wing K.<br />
Factors affecting long term results <strong>of</strong><br />
endodontic treatment. J Endodon 1990; 16:<br />
498–504.<br />
31 Kidd E A M, Smith B G N. Pickard’s Manual <strong>of</strong><br />
Operative Dentistry. 7th Edition p 59. Oxford:<br />
Oxford University Press; 1996.<br />
32 King J B, Crawford J J, Lindahl R L. Indirect<br />
pulp capping: a bacteriologic study <strong>of</strong> <strong>deep</strong><br />
<strong>carious</strong> dentine in human teeth. Oral Surg Oral<br />
Med Oral Pathol 1965; 20: 663–671.<br />
33 Bjørndal L, Larsen T, Thylstrup A. A clinical<br />
<strong>and</strong> microbiological study <strong>of</strong> <strong>deep</strong> <strong>carious</strong><br />
<strong>lesion</strong>s during stepwise excavation using long<br />
treatment intervals. Caries Res 1997; 31:<br />
411–417.<br />
34 Kidd E A M, Ricketts D N J, Beighton D.<br />
Criteria for caries removal at <strong>the</strong> enamel<br />
dentine junction: a clinical <strong>and</strong> microbiological<br />
study. Br Dent J 1996; 180: 287–291.<br />
35 Leksell E, Ridell K, Cvek M, Mejare I. Pulp<br />
exposure after stepwise versus direct complete<br />
excavation <strong>of</strong> <strong>deep</strong> <strong>carious</strong> <strong>lesion</strong>s in young<br />
posterior permanent teeth. Endod Dent<br />
Traumatol 1996; 12: 192–196.<br />
36 Magnusson B O, Sundell S O. Stepwise<br />
excavation <strong>of</strong> <strong>deep</strong> <strong>carious</strong> <strong>lesion</strong>s in primary<br />
molars. J Int Ass Dent Child 1977; 8: 36–40.<br />
37 Bjørndal L, Thylstrup A. A practice-based<br />
study on stepwise excavation <strong>of</strong> <strong>deep</strong> <strong>carious</strong><br />
<strong>lesion</strong>s in permanent teeth: a 1 year follow-up<br />
study. Community Dent Oral Epidemiol. 1998;<br />
26: 122–128.<br />
38 Bergenholtz G, Cox C F, Loesche W J, Syed S A.<br />
Bacterial leakage around dental restorations: its<br />
effect on <strong>the</strong> dental pulp. J Oral Pathol 1982; 11:<br />
439–450.<br />
39 Cox C F, Keall C L, Keall H J, Ostro E,<br />
Bergenholtz G. Biocompatibility <strong>of</strong> surfacesealed<br />
dental materials against exposed pulps.<br />
J Pros Dent 1987; 57: 1–8.<br />
40 Cox C F, Sübay R K, Suzuki S, Suzuki S H, Ostro<br />
E. Biocompatability <strong>of</strong> various dental materials:<br />
pulp healing with a surface seal. Int J Periodont<br />
Rest Dent 1996; 16: 241–251.<br />
41 Grieve A R, Alani A, Saunders W P. The effects<br />
on <strong>the</strong> dental pulp <strong>of</strong> a composite resin <strong>and</strong> two<br />
dentine bonding agents <strong>and</strong> associated<br />
bacterial microleakage. Int Endod J 1991; 24:<br />
108–118.<br />
42 Ricketts D N J, Kidd E A M, Smith B G N,<br />
Wilson R F. Clinical <strong>and</strong> radiographic diagnosis<br />
<strong>of</strong> occlusal caries: a study in vitro. J Oral Rehabil<br />
1995; 22: 15–20.<br />
43 H<strong>and</strong>elman S L, Buonocore M G, Heseck D J. A<br />
preliminary report on <strong>the</strong> effect <strong>of</strong> fissure<br />
sealant on bacteria in dental caries. J Pros<strong>the</strong>t<br />
Dent 1972; 27: 390–392.<br />
44 H<strong>and</strong>elman S L, Buonocore M G, Schoute P C.<br />
Progress report on <strong>the</strong> effect <strong>of</strong> a fissure sealant<br />
in dental caries. J Am Dent Assoc 1973; 87:<br />
1189–1191.<br />
45 H<strong>and</strong>elman S L, Wasburn F, Wopperer P.<br />
Two-year report <strong>of</strong> sealant effect on bacteria in<br />
dental caries. J Am Dent Assoc 1976; 93:<br />
967–970.<br />
46 Going R E, Loesche W J, Grainger D A, Syed S<br />
A. The viability <strong>of</strong> micro-organisms in <strong>carious</strong><br />
<strong>lesion</strong>s five years after covering with a fissure<br />
sealant. J Am Dent Assoc 1978; 97: 455–462.<br />
47 Jensen O E, H<strong>and</strong>elman S L. Effect <strong>of</strong> an<br />
autopolymerising sealant on viability <strong>of</strong><br />
micr<strong>of</strong>lora in occlusal dental caries. Sc<strong>and</strong> J<br />
Dent Res 1980; 88: 382–388.<br />
48 Mertz-Fairhurst E J, Schuster G S, Fairhurst C<br />
W. Arresting caries by sealants: results <strong>of</strong> a<br />
clinical study. J Am Dent Assoc 1986; 112:<br />
194–197.<br />
49 H<strong>and</strong>elman S L, Leverett D H, Espel<strong>and</strong> M A,<br />
Curzon J A. Clinical radiographic evaluation <strong>of</strong><br />
sealed <strong>carious</strong> <strong>and</strong> sound tooth surfaces. J Am<br />
Dent Assoc 1986; 113: 751–754.<br />
50 Mertz-Fairhurst E J, Curtis J W, Ergle J W,<br />
Rueggeberg F A, Adair S M. Ultraconservative<br />
<strong>and</strong> cariostatic sealed restorations: results at<br />
year 10. J Am Dent Assoc 1998; 129: 55–66.<br />
51 Mertz-Fairhurst E J, Call-Smith K M, Schuster<br />
G S, et al. Clinical performance <strong>of</strong> sealed<br />
composite restorations placed over caries<br />
compared with sealed <strong>and</strong> unsealed amalgam<br />
restorations. J Am Dent Assoc 1987; 115:<br />
689–694.<br />
52 Mertz-Fairhurst E J, Williams J E, Schustre G S,<br />
et al. Ultraconservative sealed restorations:<br />
three-year results. J Public Health Dent 1991;<br />
51: 239–50.<br />
53 Mertz-Fairhurst E J, Williams J E, Pierce K L,<br />
et al. Sealed restorations: 5 year results. Am J<br />
Dent 1992; 5: 5–10.<br />
54 Mertz-Fairhurst E J, Smith C D, Williams J E,<br />
et al. Cariostatic <strong>and</strong> ultraconservative sealed<br />
restorations: six year results. Quintessence Int<br />
1992; 23: 827–838.<br />
55 Mertz-Fairhurst E J, Adair S M, Sams D R, et al.<br />
Cariostatic <strong>and</strong> ultraconservative sealed<br />
restorations: nine-year results among children<br />
<strong>and</strong> adults. ASDC J Dent Child 1995; 62:<br />
97–106.<br />
56 Kidd E. Caries removal <strong>and</strong> <strong>the</strong> pulpo-dentinal<br />
complex. Dent Update 2000; 27; 476–482.<br />
610 BRITISH DENTAL JOURNAL, VOLUME 191, NO. 11, DECEMBER 8 2001
Treatment <strong>of</strong> <strong>deep</strong> <strong>carious</strong> <strong>lesion</strong>s by complete<br />
excavation or partial removal: A critical<br />
review<br />
Van Thompson, Ronald G. Craig, Fredrick A.<br />
Curro, William S. Green <strong>and</strong> Jonathan A. Ship<br />
J Am Dent Assoc 2008;139;705-712<br />
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CLINICAL PRACTICE CRITICAL REVIEW<br />
Treatment <strong>of</strong> <strong>deep</strong> <strong>carious</strong> <strong>lesion</strong>s by<br />
complete excavation or partial removal<br />
A critical review<br />
Van Thompson, DDS, PhD; Ronald G. Craig, DMD, PhD; Fredrick A. Curro, DMD, PhD;<br />
William S. Green, AB; Jonathan A. Ship, DMD<br />
The treatment <strong>of</strong> <strong>deep</strong> <strong>carious</strong><br />
<strong>lesion</strong>s approaching<br />
a healthy pulp presents a<br />
significant challenge to<br />
<strong>the</strong> practitioner. The traditional<br />
management <strong>of</strong> <strong>carious</strong><br />
<strong>lesion</strong>s <strong>of</strong> any kind dictates <strong>the</strong><br />
removal <strong>of</strong> all infected <strong>and</strong> affected<br />
dentin to prevent fur<strong>the</strong>r cariogenic<br />
activity <strong>and</strong> provide a wellmineralized<br />
base <strong>of</strong> dentin for restoration.<br />
When <strong>the</strong> procedure risks<br />
exposing or even breaching <strong>the</strong><br />
pulp, however, <strong>the</strong> course <strong>of</strong> treatment<br />
becomes less predictable <strong>and</strong><br />
may require such measures as indirect<br />
pulp capping (typically using a<br />
protective material such as a calcium<br />
hydroxide–based preparation),<br />
pulpotomy or, in <strong>the</strong> most extreme<br />
cases, pulpectomy. Choosing among<br />
<strong>the</strong>se options can be daunting for<br />
<strong>the</strong> dentist—as well as for <strong>the</strong><br />
patient, who is advised <strong>of</strong> <strong>the</strong> risks<br />
<strong>and</strong> asked to share in <strong>the</strong> decision.<br />
To preclude or at least minimize<br />
<strong>the</strong> potential complications <strong>of</strong> com-<br />
ABSTRACT<br />
Background. The classical approach to treatment <strong>of</strong> <strong>deep</strong> <strong>carious</strong><br />
<strong>lesion</strong>s approaching <strong>the</strong> pulp m<strong>and</strong>ates removing all infected <strong>and</strong> affected<br />
dentin. Several studies call this approach into question.<br />
Types <strong>of</strong> Studies Reviewed. A search <strong>of</strong> five electronic databases<br />
using selected key words to identify studies relating to partial versus complete<br />
removal <strong>of</strong> <strong>carious</strong> <strong>lesion</strong>s yielded 1,059 reports, <strong>of</strong> which <strong>the</strong> authors<br />
judged 23 to be relevant. Three articles reported <strong>the</strong> results <strong>of</strong> r<strong>and</strong>omized<br />
controlled trials.<br />
Results. The results <strong>of</strong> three r<strong>and</strong>omized controlled trials, one <strong>of</strong> which<br />
followed up patients for 10 years, provide strong evidence for <strong>the</strong> advisability<br />
<strong>of</strong> leaving behind infected dentin, <strong>the</strong> removal <strong>of</strong> which would put<br />
<strong>the</strong> pulp at risk <strong>of</strong> exposure. Several additional studies have demonstrated<br />
that cariogenic bacteria, once isolated from <strong>the</strong>ir source <strong>of</strong> nutrition by a<br />
restoration <strong>of</strong> sufficient integrity, ei<strong>the</strong>r die or remain dormant <strong>and</strong> thus<br />
pose no risk to <strong>the</strong> health <strong>of</strong> <strong>the</strong> dentition.<br />
Clinical Implications. There is substantial evidence that removing<br />
all vestiges <strong>of</strong> infected dentin from <strong>lesion</strong>s approaching <strong>the</strong> pulp is not<br />
required for caries management.<br />
Key Words. Deep caries; <strong>deep</strong> <strong>carious</strong> <strong>lesion</strong>s; partial caries removal;<br />
indirect pulp capping; pulpal exposure; stepwise excavation; alternative<br />
restorative treatment.<br />
JADA 2008;139(6):705-712.<br />
Dr. Thompson is a pr<strong>of</strong>essor <strong>and</strong> <strong>the</strong> chair, Department <strong>of</strong> Biomaterials <strong>and</strong> Biomimetics, <strong>and</strong> <strong>the</strong> director, Protocol Development <strong>and</strong> Training Core, Practitioners<br />
Engaged In Applied Research <strong>and</strong> Learning (PEARL) Network, New York University College <strong>of</strong> Dentistry, New York City.<br />
Dr. Craig is an associate pr<strong>of</strong>essor, Department <strong>of</strong> Basic Sciences <strong>and</strong> Crani<strong>of</strong>acial Biology <strong>and</strong> Department <strong>of</strong> Periodontology <strong>and</strong> Implant Dentistry, <strong>and</strong> <strong>the</strong><br />
director, Information Dissemination Core, PEARL Network, New York University College <strong>of</strong> Dentistry. Address reprint requests to Dr. Craig at New York University<br />
College <strong>of</strong> Dentistry, 345 E. 24th Street/1001S, New York, N.Y. 10010-4086, e-mail “rgc1@nyu.edu”.<br />
Dr. Curro is a clinical pr<strong>of</strong>essor, Department <strong>of</strong> Oral <strong>and</strong> Maxill<strong>of</strong>acial Pathology, Radiology, <strong>and</strong> Medicine; <strong>the</strong> director <strong>of</strong> pharmaco<strong>the</strong>rapeutic research,<br />
Bluestone Center for Clinical Research; <strong>and</strong> <strong>the</strong> director, Recruitment, Retention, <strong>and</strong> Operations Core, PEARL Network, New York University College <strong>of</strong> Dentistry,<br />
New York City.<br />
Mr. Green is a scientific writer, PEARL Network, New York University College <strong>of</strong> Dentistry, New York City.<br />
The late Dr. Ship was a pr<strong>of</strong>essor, Department <strong>of</strong> Oral <strong>and</strong> Maxill<strong>of</strong>acial Pathology, Radiology <strong>and</strong> Medicine, New York University College <strong>of</strong> Dentistry; a pr<strong>of</strong>essor<br />
<strong>of</strong> medicine, New York University School <strong>of</strong> Medicine; <strong>and</strong> <strong>the</strong> director, PEARL Network, New York University College <strong>of</strong> Dentistry, New York City.<br />
JADA, Vol. 139 http://jada.ada.org June 2008 705<br />
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CLINICAL PRACTICE CRITICAL REVIEW<br />
plete excavation <strong>of</strong> <strong>carious</strong> dentin close to <strong>the</strong><br />
pulp, several authors have investigated <strong>and</strong> proposed<br />
alternative approaches. One such method,<br />
stepwise (or two-step) excavation, involves <strong>the</strong><br />
staged removal <strong>of</strong> <strong>carious</strong> tissue. At <strong>the</strong> patient’s<br />
initial visit, once <strong>the</strong> clinician has established<br />
that <strong>the</strong> pulp still is vital, he or she partially<br />
removes necrotic infected dentin, <strong>of</strong>ten characterized<br />
as s<strong>of</strong>t <strong>and</strong> removed easily by using h<strong>and</strong><br />
instruments. The clinician <strong>the</strong>n seals <strong>the</strong> <strong>lesion</strong><br />
with a medicament such as calcium hydroxide<br />
<strong>and</strong> places a temporary restoration. At <strong>the</strong> second<br />
visit—typically some months after <strong>the</strong> first <strong>and</strong>,<br />
in some cases, up to two years later—<strong>the</strong> clinician<br />
removes all or most <strong>of</strong> <strong>the</strong> remaining infected<br />
tissue. The rationale for this approach is that by<br />
this point any remaining bacteria will have died,<br />
residual infected dentin as well as affected dentin<br />
will have remineralized, <strong>and</strong> reparative dentin<br />
will have been generated, making it easier for <strong>the</strong><br />
dentist to remove any remaining <strong>carious</strong> tissue.<br />
An even more controversial approach is conservative<br />
or ultraconservative removal <strong>of</strong> <strong>carious</strong><br />
tissue, <strong>of</strong>ten referred to as “partial caries<br />
removal.” In this method, <strong>the</strong> practitioner<br />
removes most but not all <strong>of</strong> <strong>the</strong> infected dentin,<br />
seals <strong>the</strong> cavity (with or without indirect pulp<br />
treatment) <strong>and</strong> proceeds with <strong>the</strong> restoration. The<br />
trade<strong>of</strong>f for avoiding pulpal exposure—leaving<br />
behind a layer <strong>of</strong> infected dentin—is defended by<br />
citing <strong>the</strong> substantial evidence (discussed below)<br />
that cariogenic bacteria isolated from <strong>the</strong>ir source<br />
<strong>of</strong> nutrition by a restoration <strong>of</strong> sufficient integrity<br />
ei<strong>the</strong>r die or remain quiescent <strong>and</strong> thus, given<br />
a vital pulp, pose no risk to <strong>the</strong> health <strong>of</strong> <strong>the</strong><br />
dentition.<br />
Studies comparing ei<strong>the</strong>r partial caries<br />
removal or stepwise excavation with complete<br />
removal <strong>of</strong> infected tissue from <strong>deep</strong> <strong>carious</strong><br />
<strong>lesion</strong>s were <strong>the</strong> subject <strong>of</strong> a 2006 Cochrane<br />
Review. 1 The Cochrane article, while extremely<br />
valuable, is limited in scope by virtue <strong>of</strong> being a<br />
meta-analysis focused solely on <strong>the</strong> results <strong>of</strong> r<strong>and</strong>omized<br />
controlled trials. In preparing this<br />
review, we sought to cast a wider net by performing<br />
a traditional review, taking into account<br />
observational studies <strong>and</strong> ancillary investigations<br />
that also might be <strong>of</strong> interest to <strong>the</strong> practitioner.<br />
METHODS<br />
We conducted a systematic search <strong>of</strong> five databases<br />
(MEDLINE, Evidence-Based Medicine<br />
Reviews, <strong>the</strong> Cochrane Database <strong>of</strong> Systematic<br />
706 JADA, Vol. 139 http://jada.ada.org June 2008<br />
Copyright © 2008 American Dental Association. All rights reserved.<br />
Reviews, Cochrane Central Register <strong>of</strong> Controlled<br />
Trials <strong>and</strong> OVID’s Database <strong>of</strong> Abstracts <strong>of</strong><br />
Reviews <strong>of</strong> Effects) using <strong>the</strong> following key words:<br />
<strong>deep</strong> caries; <strong>deep</strong> <strong>carious</strong> <strong>lesion</strong>s; partial caries<br />
removal; indirect pulp capping; pulpal exposure;<br />
stepwise excavation; alternative restorative treatment<br />
(ART). We limited <strong>the</strong> search to reports<br />
written in English describing studies using<br />
human subjects <strong>and</strong> published from 1950 through<br />
<strong>the</strong> first week <strong>of</strong> November 2007. The literature<br />
search yielded 1,059 articles, <strong>of</strong> which 23—<br />
including articles relating to restoration<br />
longevity, cariogenic activity <strong>and</strong> pulp vitality, as<br />
well as those directly addressing partial versus<br />
complete removal <strong>of</strong> <strong>deep</strong> <strong>carious</strong> <strong>lesion</strong>s—<br />
reported results we deemed directly relevant.<br />
RESULTS<br />
We identified 10 articles2-11 accounting for six<br />
studies (four <strong>of</strong> <strong>the</strong>se articles reported follow-up<br />
results) that directly address <strong>the</strong> issue <strong>of</strong> partial<br />
removal <strong>of</strong> <strong>carious</strong> tissue from <strong>deep</strong> <strong>lesion</strong>s<br />
(Table). Three investigations stood out by virtue<br />
<strong>of</strong> being r<strong>and</strong>omized controlled trials: <strong>the</strong> 1987<br />
study by Mertz-Fairhurst <strong>and</strong> colleagues, 2 <strong>the</strong><br />
1999 study by Ribeiro <strong>and</strong> colleagues5 <strong>and</strong> <strong>the</strong><br />
2004 study by Foley <strong>and</strong> colleagues. 6<br />
Mertz-Fairhurst <strong>and</strong> colleagues2 used a r<strong>and</strong>omized<br />
split-mouth, four-celled design to compare<br />
sealed composite restorations in teeth<br />
treated via partial caries removal with both<br />
sealed <strong>and</strong> unsealed amalgam restorations in<br />
teeth from which all <strong>carious</strong> tissue had been<br />
removed. The study population consisted <strong>of</strong> 123<br />
patients aged 8 to 52 years who had at least one<br />
pair <strong>of</strong> frank Class I <strong>lesion</strong>s that, according to <strong>the</strong><br />
investigators’ radiographic evaluation, extended<br />
as far as halfway from <strong>the</strong> dentinoenamel junction<br />
(DEJ) to <strong>the</strong> pulp. A total <strong>of</strong> 156 pairs (312<br />
teeth) were included in <strong>the</strong> study. The investigators<br />
evaluated restorations radiographically as<br />
well as clinically (using a modification <strong>of</strong> <strong>the</strong><br />
Ryge/Snyder criteria12 ) at six months, one year<br />
<strong>and</strong> two years after treatment. They detected no<br />
significant differences among <strong>the</strong> three treatments—sealed<br />
conservative, sealed amalgam,<br />
unsealed amalgam—at any period. Mertz-<br />
ABBREVIATION KEY. ART: Alternative restorative<br />
treatment. CFU: Colony-forming unit. DEJ: Dentinoenamel<br />
junction. GIC: Glass ionomer cement.<br />
PEARL: Practitioners Engaged in Applied Research<br />
<strong>and</strong> Learning.<br />
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TABLE<br />
Summary <strong>of</strong> studies examining partial caries removal.<br />
Fairhurst’s group followed up <strong>the</strong>se patients<br />
across <strong>the</strong> next decade, 3,4 finally observing that<br />
“<strong>the</strong> bonded <strong>and</strong> sealed composite restorations<br />
placed over <strong>the</strong> frank cavitated <strong>lesion</strong>s [had]<br />
arrested <strong>the</strong> clinical progress <strong>of</strong> <strong>the</strong>se <strong>lesion</strong>s for<br />
10 years.” 4<br />
The r<strong>and</strong>omized controlled trial conducted by<br />
Ribeiro <strong>and</strong> colleagues, 5 in which <strong>the</strong>y evaluated<br />
<strong>the</strong> performance <strong>of</strong> a dentin adhesive system, also<br />
served to test <strong>the</strong> relative performance <strong>of</strong> com-<br />
CLINICAL PRACTICE CRITICAL REVIEW<br />
STUDY STUDY DESIGN FOLLOW-UP PERIOD RESULTS<br />
R<strong>and</strong>omized Controlled Trials<br />
Mertz-Fairhurst <strong>and</strong> colleagues 2-4 Split-mouth r<strong>and</strong>omized<br />
trial <strong>of</strong> 156 pairs <strong>of</strong> teeth,<br />
in subjects aged 8 through<br />
52 years, comparing sealed<br />
resin-based composites<br />
after partial caries removal<br />
versus sealed <strong>and</strong> unsealed<br />
amalgams after complete<br />
caries removal<br />
Ribeiro <strong>and</strong> colleagues 5 R<strong>and</strong>omized controlled<br />
trial <strong>of</strong> 48 primary molars,<br />
in subjects aged 7 through<br />
11 years, restored with a<br />
resin-bonded composite,<br />
comparing partial versus<br />
complete caries removal<br />
Foley <strong>and</strong> colleagues 6 Split-mouth r<strong>and</strong>omized<br />
controlled trial <strong>of</strong> 88 teeth<br />
in 44 subjects aged 3.7<br />
through 9.5 years; teeth<br />
divided into four groups:<br />
complete or partial caries<br />
removal restored with<br />
copper phosphate cement<br />
with or without glass<br />
ionomer cement or<br />
amalgam<br />
Observational Studies<br />
Fairbourn <strong>and</strong> colleagues 10 Observational study <strong>of</strong> <strong>the</strong><br />
effect on cultivatable flora<br />
after partial caries removal<br />
followed by zinc oxide<br />
eugenol with or without<br />
calcium hydroxide base in<br />
40 permanent teeth<br />
Maltz <strong>and</strong> colleagues 7,9,<br />
Oliveira <strong>and</strong> colleagues 8<br />
Observational study <strong>of</strong> partial<br />
caries removal in 32<br />
subjects aged 12 through<br />
23 years<br />
Marchi <strong>and</strong> colleagues 11 Observational study <strong>of</strong> <strong>the</strong><br />
effect <strong>of</strong> calcium hydroxide<br />
<strong>and</strong> resin-modified glass<br />
ionomer liners on indirect<br />
pulp caps <strong>of</strong> 27 primary<br />
molars in subjects aged 4<br />
through 9 years<br />
Clinical <strong>and</strong> radiographic<br />
follow-up at<br />
six months <strong>and</strong> at one,<br />
two, five <strong>and</strong> 10 years<br />
Extracted near time <strong>of</strong><br />
exfoliation <strong>and</strong> examined<br />
radiographically<br />
<strong>and</strong> via electron<br />
microscopy<br />
Restorations assessed<br />
clinically at six-month<br />
intervals for 24<br />
months <strong>and</strong> radiographically<br />
at 12 <strong>and</strong><br />
24 months<br />
At reentry after five<br />
months, <strong>the</strong> remaining<br />
infected dentin was<br />
removed <strong>and</strong> cultivated<br />
for microbiological<br />
analysis<br />
Clinical, radiographic<br />
<strong>and</strong> microbiological<br />
data collected at<br />
reentry at six to seven,<br />
14 to 18, <strong>and</strong> 36 to 45<br />
months after<br />
treatment<br />
Examined at four<br />
years for clinical or<br />
radiographic evidence<br />
<strong>of</strong> pulp pathology<br />
Copyright © 2008 American Dental Association. All rights reserved.<br />
No differences noted among<br />
groups at any time <strong>of</strong><br />
follow-up<br />
No differences noted<br />
between groups<br />
Use <strong>of</strong> copper phosphate<br />
cement plus glass ionomer<br />
cement resulted in more<br />
abscess or sinus formation;<br />
use <strong>of</strong> glass ionomer cement<br />
alone resulted in no differences<br />
between groups<br />
Nine <strong>of</strong> 20 teeth treated<br />
with calcium hydroxide <strong>and</strong><br />
five <strong>of</strong> 20 teeth treated with<br />
zinc oxide–eugenol were<br />
sterile<br />
Remineralization occurred<br />
<strong>and</strong> caries was arrested at<br />
each <strong>of</strong> <strong>the</strong> three times <strong>of</strong><br />
follow-up<br />
88 percent success for calcium<br />
hydroxide <strong>and</strong> 93 percent<br />
success for resinmodified<br />
glass ionomer<br />
plete <strong>and</strong> partial caries removal. After etching,<br />
<strong>the</strong> investigators applied a bonding agent to both<br />
<strong>carious</strong> <strong>and</strong> non<strong>carious</strong> dentin in 48 primary<br />
molars <strong>of</strong> 38 children aged 7 to 11 years. In one<br />
group, <strong>the</strong> clinicians removed <strong>carious</strong> dentin completely<br />
from <strong>the</strong> DEJ but only superficially from<br />
<strong>the</strong> remainder <strong>of</strong> <strong>the</strong> cavity; <strong>the</strong>y treated a second<br />
group by completely excavating caries. The investigators<br />
extracted 40 teeth (20 from each group)<br />
at about <strong>the</strong> time <strong>of</strong> exfoliation (approximately<br />
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CLINICAL PRACTICE CRITICAL REVIEW<br />
one year after treatment) <strong>and</strong> subjected <strong>the</strong> teeth<br />
to radiographic <strong>and</strong> scanning electron microscopic<br />
analysis. These results, as well as evaluations <strong>of</strong><br />
retention rates, marginal integrity <strong>and</strong> pulpal<br />
symptoms, indicated no significant differences<br />
between <strong>the</strong> two groups.<br />
A more recent study by Foley <strong>and</strong> colleagues 6<br />
compared <strong>the</strong> cariostatic effectiveness <strong>of</strong> alternative<br />
restorative materials in both partial <strong>and</strong> complete<br />
removal <strong>of</strong> <strong>carious</strong> tissue. The authors used<br />
a split-mouth design in 44 patients aged 3.7 to 9.5<br />
years who had at least one pair <strong>of</strong> previously<br />
unrestored primary molars that had no pulpal<br />
involvement. They treated one tooth <strong>of</strong> each pair<br />
by complete caries removal <strong>and</strong> <strong>the</strong> o<strong>the</strong>r by<br />
incomplete caries removal followed by restoration<br />
using copper phosphate cement, glass ionomer<br />
cement (GIC) or both, or a material “<strong>of</strong> <strong>the</strong> operator’s<br />
choice” (such as amalgam). At 24 months<br />
after treatment, teeth that had undergone partial<br />
caries removal followed by restoration with<br />
copper phosphate cement <strong>and</strong> GIC exhibited<br />
greater abscess or sinus formation than did teeth<br />
that had undergone o<strong>the</strong>r treatments. Restorations<br />
placed in teeth treated with GIC alone after<br />
partial caries removal, however, exhibited a durability<br />
<strong>and</strong> effectiveness comparable with those<br />
placed in teeth that had undergone complete<br />
caries removal.<br />
In an observational study, Maltz <strong>and</strong> colleagues<br />
7 investigated <strong>the</strong> effects <strong>of</strong> partial caries<br />
removal in 32 teeth with <strong>deep</strong> <strong>carious</strong> <strong>lesion</strong>s. On<br />
<strong>the</strong> basis <strong>of</strong> clinical, radiographic <strong>and</strong> microbiologic<br />
evidence at reentry six to seven months after<br />
treatment (after which <strong>the</strong>y placed a permanent<br />
restoration), <strong>the</strong> authors concluded that remineralization<br />
had taken place <strong>and</strong> that caries had<br />
been arrested. In follow-up studies <strong>of</strong> <strong>the</strong> same<br />
patients, <strong>the</strong> authors reported similar results 14<br />
to 18 months after treatment 8 <strong>and</strong> 36 to 45<br />
months after treatment. 9<br />
Fairbourn <strong>and</strong> colleagues 10 reported <strong>the</strong> effect<br />
<strong>of</strong> indirect pulp capping, after partial caries<br />
removal, on cultivable aerobic <strong>and</strong> anaerobic bacteria.<br />
These investigators restored 40 permanent<br />
asymptomatic teeth that had <strong>carious</strong> occlusal or<br />
interproximal <strong>lesion</strong>s approaching <strong>the</strong> pulp after<br />
partial excavation <strong>of</strong> infected dentin in which zinc<br />
oxide–eugenol (Caulk IRM Intermediate Restorative<br />
Material, Dentsply Caulk, Milford, Del.) with<br />
or without a calcium hydroxide base (Dycal,<br />
Dentsply Caulk) was used. After five months,<br />
<strong>the</strong>y isolated <strong>the</strong> teeth, excavated <strong>the</strong> remaining<br />
708 JADA, Vol. 139 http://jada.ada.org June 2008<br />
Copyright © 2008 American Dental Association. All rights reserved.<br />
infected dentin <strong>and</strong> cultivated it to identify bacterial<br />
species. Both groups showed a dramatic<br />
decrease in colony-forming units (CFUs); nine <strong>of</strong><br />
20 teeth treated with <strong>the</strong> calcium hydroxide liner<br />
<strong>and</strong> five <strong>of</strong> 20 teeth treated with zinc oxide–<br />
eugenol had become operationally sterile (< 300<br />
CFUs per milligram <strong>of</strong> dentin). The authors concluded<br />
that reentry to remove residual infected<br />
dentin with ei<strong>the</strong>r restorative material may be<br />
unnecessary, provided that <strong>the</strong> restoration maintains<br />
an effective seal.<br />
Marchi <strong>and</strong> colleagues 11 studied <strong>the</strong> effectiveness<br />
<strong>of</strong> two protective liners, calcium hydroxide<br />
<strong>and</strong> resin-modified glass ionomer, in <strong>the</strong> indirect<br />
pulp treatment <strong>of</strong> 27 primary molars. At four<br />
years after treatment, <strong>the</strong> success rate using <strong>the</strong><br />
former was 88.8 percent <strong>and</strong> using <strong>the</strong> latter was<br />
93 percent. The investigators defined “success”<br />
essentially as <strong>the</strong> absence <strong>of</strong> any “clinical radiographic<br />
signs or symptoms <strong>of</strong> irreversible pulp<br />
pathologies or necrosis.” The authors concluded<br />
that “indirect pulp capping in primary teeth<br />
arrests <strong>the</strong> progression <strong>of</strong> <strong>the</strong> underlying caries,<br />
regardless <strong>of</strong> <strong>the</strong> material used as a liner.” 11<br />
Several studies that did not focus on partial<br />
caries removal never<strong>the</strong>less are relevant to <strong>the</strong><br />
treatment <strong>of</strong> <strong>deep</strong> <strong>carious</strong> <strong>lesion</strong>s. There has been<br />
evidence for several decades, for example, that<br />
caries development is arrested in sealed <strong>lesion</strong>s.<br />
H<strong>and</strong>elman <strong>and</strong> colleagues 13-17 have published<br />
extensively on this subject. Perhaps most frequently<br />
cited is <strong>the</strong>ir 1976 study, 13 in which <strong>the</strong>y<br />
placed sealants on 60 teeth with <strong>carious</strong> <strong>lesion</strong>s<br />
extending into <strong>the</strong> dentin; 29 unsealed teeth<br />
served as control specimens. They sampled teeth<br />
for bacterial culture at periods ranging from one<br />
week to two years; at <strong>the</strong> latter point, <strong>the</strong>y found<br />
a substantial decrease in <strong>the</strong> number <strong>of</strong> cultivable<br />
microorganisms in sealed <strong>lesion</strong>s when compared<br />
with <strong>the</strong> unsealed control teeth. Interestingly,<br />
<strong>the</strong>y found <strong>the</strong> greatest amount <strong>of</strong> bacterial<br />
reduction within two weeks after treatment. In a<br />
subsequent study, H<strong>and</strong>elman’s group, 14<br />
describing a radiographic analysis <strong>of</strong> teeth<br />
treated similarly to those in <strong>the</strong> 1976 study,<br />
reported a significant decrease in caries penetration<br />
in teeth in which <strong>the</strong> sealant remained<br />
intact. Bjorndal <strong>and</strong> colleagues, 18 performing stepwise<br />
excavation, cultured bacteria from <strong>the</strong><br />
dentin <strong>of</strong> 19 teeth after <strong>the</strong> initial procedure <strong>and</strong><br />
after intervals <strong>of</strong> six to 12 months; at <strong>the</strong> latter<br />
point, <strong>the</strong>y observed that CFUs had been reduced<br />
substantially.<br />
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Two r<strong>and</strong>omized controlled trials comparing<br />
stepwise <strong>and</strong> complete excavation, while only tangentially<br />
relevant to <strong>the</strong> partial caries removal<br />
technique, never<strong>the</strong>less are important for results<br />
relevant to <strong>the</strong> risk <strong>of</strong> pulpal complications after<br />
complete removal <strong>of</strong> <strong>deep</strong> caries. Magnusson <strong>and</strong><br />
Sundell 19 reported postprocedural pulpal complications<br />
in eight (15 percent) <strong>of</strong> 55 teeth treated by<br />
stepwise excavation <strong>and</strong> in 29 (53 percent) <strong>of</strong> 55<br />
teeth treated by direct excavation. Leksell <strong>and</strong><br />
colleagues 20 similarly reported pulpal exposure in<br />
10 (17.5 percent) <strong>of</strong> 57 teeth treated in stepwise<br />
fashion compared with 28 (40.0 percent) <strong>of</strong> 70<br />
teeth treated by direct excavation.<br />
A 2002 study comparing <strong>the</strong> efficacy <strong>of</strong> two<br />
materials used in conjunction with indirect pulp<br />
capping in 48 primary molars reported a success<br />
rate, as measured by absence <strong>of</strong> irreversible pulp<br />
pathology, <strong>of</strong> 96 percent for teeth treated with a<br />
proprietary adhesive resin system at two years<br />
after treatment. 21<br />
Al-Zayer <strong>and</strong> colleagues 22 retrospectively analyzed<br />
187 primary posterior teeth (132 patients)<br />
treated with indirect pulp capping in which sufficient<br />
<strong>carious</strong> dentin was left to preclude pulpal<br />
exposure. The authors <strong>the</strong>n followed up patients<br />
clinically <strong>and</strong> radiographically for periods ranging<br />
from two weeks to 73 months after treatment. Of<br />
<strong>the</strong> 187 teeth in <strong>the</strong> study, nine (4.8 percent)<br />
experienced complications, amounting to a 95 percent<br />
success rate.<br />
Kreulen <strong>and</strong> colleagues, 23 using a split-mouth<br />
model, sampled <strong>carious</strong> dentin from molars before<br />
restoring <strong>the</strong> teeth using ei<strong>the</strong>r a “biologically<br />
active” (that is, antimicrobial) resin-modified glass<br />
ionomer preparation or amalgam. They processed<br />
samples for viable bacteria <strong>and</strong> evaluated <strong>the</strong>m for<br />
color <strong>and</strong> consistency. Dentin from <strong>the</strong> same sites<br />
similarly sampled <strong>and</strong> evaluated at six months<br />
after treatment in 39 patients from both groups<br />
exhibited a significant decrease in <strong>the</strong> mean<br />
number <strong>of</strong> bacteria <strong>and</strong> a significant “overall<br />
treatment” effect for color <strong>and</strong> consistency.<br />
In a microbiological study <strong>of</strong> dentin samples<br />
taken from 40 <strong>carious</strong> <strong>lesion</strong>s before <strong>and</strong> after<br />
undergoing ART, Bonecker <strong>and</strong> colleagues 24 found<br />
significant reductions in <strong>the</strong> frequency <strong>and</strong> proportions<br />
<strong>of</strong> total viable cells as well as <strong>of</strong> mutans<br />
streptococci (but not lactobacilli) in restorations<br />
sealed with a GIC.<br />
Vij <strong>and</strong> colleagues 25 conducted a retrospective<br />
analysis <strong>of</strong> two approaches to treating <strong>carious</strong><br />
<strong>lesion</strong>s approaching <strong>the</strong> pulp in 226 primary<br />
Copyright © 2008 American Dental Association. All rights reserved.<br />
CLINICAL PRACTICE CRITICAL REVIEW<br />
molars (141 patients), including 133 teeth from a<br />
previous study 26 that used similar criteria for <strong>the</strong><br />
same treatments. The investigators treated all<br />
teeth in two stages (not to be confused with stepwise<br />
excavation). First, <strong>the</strong>y removed superficial<br />
<strong>carious</strong> tissue <strong>and</strong> temporarily filled <strong>the</strong> cavity<br />
with ei<strong>the</strong>r zinc oxide–eugenol or GIC. Then, at a<br />
second appointment one to three months later,<br />
<strong>the</strong>y ei<strong>the</strong>r removed <strong>the</strong> remaining <strong>carious</strong> tissue<br />
completely <strong>and</strong> performed a pulpotomy followed<br />
by treatment with formocreosol or removed all<br />
but <strong>the</strong> <strong>deep</strong>est layer <strong>of</strong> remaining <strong>carious</strong> dentin<br />
<strong>and</strong> performed indirect pulp capping by using one<br />
<strong>of</strong> two GIC preparations. At three years after<br />
treatment, <strong>the</strong> success rate—as measured by <strong>the</strong><br />
absence <strong>of</strong> swelling, abnormal mobility, pain <strong>and</strong><br />
radiographic signs <strong>of</strong> pathology—was 94 percent<br />
for teeth treated by means <strong>of</strong> partial caries<br />
removal <strong>and</strong> indirect pulp capping <strong>and</strong> 70 percent<br />
for <strong>the</strong> group treated by means <strong>of</strong> formocreosol<br />
pulpotomy. While this study cannot serve to measure<br />
<strong>the</strong> relative merits <strong>of</strong> partial caries <strong>and</strong> complete<br />
caries removal per se, it demonstrates <strong>the</strong><br />
relative superiority <strong>of</strong> partial caries removal to a<br />
technique (formocreosol pulpotomy) that some<br />
consider a viable alternative.<br />
DISCUSSION<br />
Is it necessary to remove all <strong>carious</strong> tissue from<br />
<strong>lesion</strong>s approaching <strong>the</strong> pulp? Although <strong>the</strong>re is<br />
substantial evidence to <strong>the</strong> contrary, most practitioners<br />
continue to follow <strong>the</strong> basic principle<br />
guiding any surgeon: that one must eradicate any<br />
<strong>and</strong> all affected tissue from <strong>the</strong> site <strong>of</strong> an infection.<br />
It is not clear, however, whe<strong>the</strong>r this principle<br />
is, or ought to be, followed at all times. In<br />
conventional endodontic <strong>the</strong>rapy, for example,<br />
which has a high rate <strong>of</strong> clinical success, it is<br />
likely that viable bacteria <strong>and</strong> necrotic host tissue<br />
typically remain in <strong>the</strong> root canal system after<br />
instrumentation <strong>and</strong> obturation. 27<br />
The conventional treatment paradigm has a<br />
long history. G.V. Black, in his classic 1908 text,<br />
asserted that “it is better to expose <strong>the</strong> pulp <strong>of</strong> a<br />
tooth than to leave it covered only with s<strong>of</strong>tened<br />
dentine.” 28 More recently, <strong>the</strong> majority <strong>of</strong> respondents<br />
to a survey on this subject indicated that<br />
<strong>the</strong>y would remove all <strong>carious</strong> tissue even if <strong>the</strong><br />
procedure, in <strong>the</strong>ir judgment, would risk pulpal<br />
exposure; only about one in five respondents said<br />
<strong>the</strong>y would choose to proceed with partial caries<br />
removal, <strong>and</strong> a slightly higher proportion indicated<br />
that <strong>the</strong>y would initiate or refer <strong>the</strong> patient<br />
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for endodontic treatment. 29 In ano<strong>the</strong>r recent<br />
survey, conducted in 2006, <strong>the</strong> majority <strong>of</strong><br />
respondents opted for pulpotomy as <strong>the</strong> treatment<br />
<strong>of</strong> choice in a similar scenario. 30<br />
Ironically, G.V. Black also stated that it is<br />
imperative that dentists underst<strong>and</strong> <strong>the</strong><br />
pathology <strong>of</strong> <strong>the</strong> caries process lest <strong>the</strong>y be<br />
reduced to <strong>the</strong> role <strong>of</strong> mechanics. 31 It is interesting<br />
to speculate, given our ability to create a<br />
restoration with well-sealed margins <strong>and</strong> associated<br />
grooves <strong>and</strong> fissures, what Black would say<br />
about <strong>the</strong> subject <strong>of</strong> partial caries removal today.<br />
Several <strong>of</strong> <strong>the</strong> studies cited above (such as those<br />
by H<strong>and</strong>elman <strong>and</strong> colleagues, 13 Kreulen <strong>and</strong> colleagues,<br />
23 Maltz <strong>and</strong> colleagues 7-9 <strong>and</strong> Bonecker<br />
<strong>and</strong> colleagues 24 ) have demonstrated that bacterial<br />
counts under sealed restorations become<br />
drastically reduced. In <strong>the</strong>ir 2002 study, Maltz<br />
<strong>and</strong> colleagues, 7 citing significant decreases in<br />
counts <strong>of</strong> both aerobic <strong>and</strong> anaerobic viable bacteria<br />
<strong>and</strong> radiographic evidence <strong>of</strong> a mineral gain<br />
in affected areas, concluded that “complete<br />
dentinal caries <strong>lesion</strong> removal is not essential to<br />
<strong>the</strong> control <strong>of</strong> caries <strong>lesion</strong>s”—a conclusion that<br />
was repeated in two follow-up studies. 8,9 Kidd, 32<br />
who cited most <strong>of</strong> <strong>the</strong>se same sources <strong>and</strong> several<br />
o<strong>the</strong>rs, including studies <strong>of</strong> stepwise excavation<br />
<strong>and</strong> partial caries removal, concluded that “<strong>the</strong>re<br />
is no clear evidence that it is deleterious to leave<br />
infected dentine.”<br />
Some <strong>of</strong> <strong>the</strong> best evidence for <strong>the</strong> rationale<br />
underlying partial caries removal can be found in<br />
studies <strong>of</strong> a related technique, <strong>the</strong> stepwise excavation<br />
approach. The literature regarding stepwise<br />
excavation 18-20,33,34 has reported consistently<br />
that residual <strong>carious</strong> dentin recedes <strong>and</strong> hardens<br />
under temporary restorations in <strong>the</strong> interim<br />
between <strong>the</strong> initial excavation <strong>and</strong> reentry. But<br />
as Kidd 32 stated, “Why re-enter?” In o<strong>the</strong>r words,<br />
if <strong>the</strong> goal is to avoid pulpal exposure <strong>and</strong><br />
residual <strong>carious</strong> dentin poses no threat to <strong>the</strong><br />
dentition, why subject <strong>the</strong> patient to a second<br />
excavation?<br />
Assuming it is preferable to leave caries in<br />
<strong>deep</strong> restorations, must <strong>the</strong> practitioner alter his<br />
or her restorative technique? The previously cited<br />
survey <strong>of</strong> dentists conducted by <strong>the</strong> Practitioners<br />
Engaged in Applied Research <strong>and</strong> Learning<br />
(PEARL), a practice-based research network at<br />
<strong>the</strong> New York University College <strong>of</strong> Dentistry<br />
sponsored by <strong>the</strong> National Institutes <strong>of</strong> Health, 29<br />
may hold an answer to that. The survey’s<br />
respondents, who represented a wide range <strong>of</strong><br />
710 JADA, Vol. 139 http://jada.ada.org June 2008<br />
Copyright © 2008 American Dental Association. All rights reserved.<br />
approaches to restoration, stated that <strong>the</strong>y<br />
expected that roughly <strong>the</strong> same percentage <strong>of</strong><br />
<strong>the</strong>ir patients would require endodontic treatment<br />
three to five years after treatment regardless<br />
<strong>of</strong> whe<strong>the</strong>r <strong>the</strong> respondent favored complete<br />
or partial caries removal in <strong>deep</strong> <strong>lesion</strong>s <strong>and</strong><br />
regardless <strong>of</strong> <strong>the</strong> respondent’s restoration technique.<br />
Evidence from <strong>the</strong> literature also suggests<br />
that a change <strong>of</strong> approach is unnecessary. Even<br />
before <strong>the</strong> advent <strong>of</strong> dentin bonding, <strong>the</strong> efficacy<br />
<strong>of</strong> bonding to enamel alone was demonstrated in a<br />
17-year recall study <strong>of</strong> a large-particle ultraviolet<br />
light–cured resin-based composite in Class I <strong>and</strong><br />
Class II restorations. 35 Moreover, Mertz-Fairhurst<br />
<strong>and</strong> colleagues 4 demonstrated that bonding to<br />
enamel alone (with <strong>carious</strong> dentin remaining) was<br />
sufficient at 10 years. Dentin bonding adds to our<br />
ability to seal restorations, but its long-term efficacy<br />
is still in question. 36<br />
Partial removal <strong>of</strong> caries from <strong>deep</strong> <strong>lesion</strong>s usually<br />
involves complete removal <strong>of</strong> <strong>carious</strong> tissue<br />
from cavity walls but limited removal from <strong>the</strong><br />
pulpal floor <strong>and</strong> axial wall, which are sites <strong>of</strong><br />
reduced bond strength. Resin-based composite<br />
restoration polymerization shrinkage can result<br />
in retraction <strong>of</strong> <strong>the</strong> bonding agent from <strong>the</strong> pulpal<br />
floor or axial wall <strong>of</strong> sound dentin. 37,38 The<br />
resulting gap can fill with fluid, <strong>and</strong> with tooth<br />
deformation, <strong>the</strong> fluid is forced down open<br />
dentinal tubules, causing postoperative “occlusal<br />
loading sensitivity.” While clinicians may find<br />
pulpal floor gaps more <strong>of</strong>ten when <strong>deep</strong> caries<br />
remains because <strong>of</strong> composite’s inability to bond<br />
completely to caries-infected <strong>and</strong> caries-affected<br />
dentin, 39-42 <strong>the</strong> chance <strong>of</strong> postoperative hypersensitivity<br />
might be reduced because <strong>the</strong> pulp is protected<br />
from fluid flow in <strong>the</strong> tubules by <strong>the</strong> lowpermeability<br />
zone in <strong>deep</strong> infected dentin. 43,44 On<br />
<strong>the</strong> basis <strong>of</strong> <strong>the</strong>se findings, one might suggest<br />
that infected dentin be removed completely from<br />
preparation walls but selectively from <strong>the</strong> pulpal<br />
floor or axial wall.<br />
Finally, it is worthwhile to consider <strong>the</strong> recent<br />
meta-analysis 1 that pooled <strong>the</strong> results <strong>of</strong> four <strong>of</strong><br />
<strong>the</strong> r<strong>and</strong>omized controlled trials discussed earlier:<br />
those by <strong>the</strong> Mertz-Fairhurst, 2 Ribeiro, 5 Magnusson<br />
19 <strong>and</strong> Leksell 20 research groups. The<br />
review is entitled “Complete or Ultraconservative<br />
Removal <strong>of</strong> Decayed Tissue in Unfilled Teeth,”<br />
<strong>and</strong> while one can argue that “ultraconservative”<br />
does not apply to <strong>the</strong> focus <strong>of</strong> <strong>the</strong> studies by Magnusson<br />
<strong>and</strong> colleagues 19 <strong>and</strong> Leksell <strong>and</strong> colleagues<br />
20 (stepwise excavation), <strong>the</strong> authors nev-<br />
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er<strong>the</strong>less came to <strong>the</strong> conclusion—tempered by<br />
<strong>the</strong>ir observation that <strong>the</strong> number <strong>of</strong> <strong>the</strong>se trials<br />
is small—that “partial caries removal is …<br />
preferable to complete caries removal in <strong>the</strong> <strong>deep</strong><br />
<strong>lesion</strong>, in order to reduce <strong>the</strong> risk <strong>of</strong> <strong>carious</strong> exposure<br />
[<strong>of</strong> <strong>the</strong> pulp].” 1 Apparently, dentists need<br />
more evidence before <strong>the</strong>y will accept this determination—despite<br />
<strong>the</strong> fact that (to our knowledge)<br />
no study has been initiated to prove <strong>the</strong><br />
desirability <strong>of</strong> removing all infected dentin. An<br />
observational study under way within <strong>the</strong><br />
PEARL practice-based research network will<br />
attempt to fill in some <strong>of</strong> <strong>the</strong> gaps in our underst<strong>and</strong>ing<br />
<strong>of</strong> <strong>deep</strong> caries treatment <strong>and</strong> may provide<br />
<strong>the</strong> basis for a clinical trial.<br />
CONCLUSION<br />
On <strong>the</strong> basis <strong>of</strong> <strong>the</strong> studies cited in this review,<br />
one can state that <strong>the</strong>re is substantial evidence<br />
that <strong>the</strong> removal <strong>of</strong> all infected dentin in <strong>deep</strong><br />
<strong>carious</strong> <strong>lesion</strong>s is not required for successful<br />
caries treatment—provided that <strong>the</strong> restoration<br />
can seal <strong>the</strong> <strong>lesion</strong> from <strong>the</strong> oral environment<br />
effectively. However, before this concept is<br />
accepted generally by <strong>the</strong> dental pr<strong>of</strong>ession, additional<br />
clinical trials may be needed. ■<br />
Disclosures. None <strong>of</strong> <strong>the</strong> authors reported any disclosures.<br />
The authors acknowledge <strong>the</strong> support <strong>of</strong> <strong>the</strong> National Institute <strong>of</strong><br />
Dental <strong>and</strong> Crani<strong>of</strong>acial Research, National Institutes <strong>of</strong> Health,<br />
through grant U-01-DE016755-01 awarded to <strong>the</strong> New York University<br />
College <strong>of</strong> Dentistry, New York City.<br />
1. Ricketts DN, Kidd EA, Innes N, Clarkson J. Complete or ultraconservative<br />
removal <strong>of</strong> decayed tissue in unfilled teeth. Cochrane Database<br />
Syst Rev 2006;3:CD003808.<br />
2. Mertz-Fairhurst EJ, Call-Smith KM, Shuster GS, et al. Clinical<br />
performance <strong>of</strong> sealed composite restorations placed over caries compared<br />
with sealed <strong>and</strong> unsealed amagam restorations. JADA<br />
1987;115(5):689-694.<br />
3. Mertz-Fairhurst EJ, Richards EE, Williams JE, Smith CD,<br />
Mackert JR Jr, Schuster GS, et al. Sealed restorations: 5-year results.<br />
Am J Dent 1992;5(1):5-10.<br />
4. Mertz-Fairhurst EJ, Curtis JW Jr, Ergle JW, Rueggeberg FA,<br />
Adair SM. Ultraconservative <strong>and</strong> cariostatic sealed restorations:<br />
results at year 10. JADA 1998;129(1):55-66.<br />
5. Ribeiro CC, Baratieri LN, Perdigao J, Baratieri NM, Ritter AV. A<br />
clinical, radiographic, <strong>and</strong> scanning electron microscopic evaluation <strong>of</strong><br />
adhesive restorations on <strong>carious</strong> dentin in primary teeth. Quintessence<br />
Int 1999;30(9):591-599.<br />
6. Foley J, Evans D, Blackwell A. Partial caries removal <strong>and</strong> cariostatic<br />
materials in <strong>carious</strong> primary molar teeth: a r<strong>and</strong>omised controlled<br />
clinical trial. Br Dent J 2004;197(11):697-701; discussion 689.<br />
7. Maltz M, de Oliveira EF, Fontanella V, Bianchi R. A clinical,<br />
microbiologic, <strong>and</strong> radiographic study <strong>of</strong> <strong>deep</strong> caries <strong>lesion</strong>s after<br />
incomplete caries removal. Quintessence Int 2002;33(2):151-159.<br />
8. Oliveira EF, Carminatti G, Fontanella V, Maltz M. The monitoring<br />
<strong>of</strong> <strong>deep</strong> caries <strong>lesion</strong>s after incomplete dentine caries removal: results<br />
after 14-18 months. Clin Oral Investig 2006;10(2):134-139.<br />
9. Maltz M, Oliveira EF, Fontanella V, Carminatti G. Deep caries<br />
<strong>lesion</strong>s after incomplete dentine caries removal: 40-month follow-up<br />
study. Caries Res 2007;41(6):493-496.<br />
10. Fairbourn DR, Charbeneau GT, Loesche WJ. Effect <strong>of</strong> improved<br />
Dycal <strong>and</strong> IRM on bacteria in <strong>deep</strong> <strong>carious</strong> <strong>lesion</strong>s. JADA<br />
1980;100(4):547-552.<br />
Copyright © 2008 American Dental Association. All rights reserved.<br />
CLINICAL PRACTICE CRITICAL REVIEW<br />
11. Marchi JJ, de Araujo FB, Froner AM, Straffon LH, Nor JE. Indirect<br />
pulp capping in <strong>the</strong> primary dentition: a 4 year follow-up study. J<br />
Clin Pediatr Dent 2006;31(2):68-71.<br />
12. Ryge G, Snyder M. Evaluating <strong>the</strong> clinical quality <strong>of</strong> restorations.<br />
JADA 1973;87(2):369-377.<br />
13. H<strong>and</strong>elman SL, Washburn F, Wopperer P. Two-year report <strong>of</strong><br />
sealant effect on bacteria in dental caries. JADA 1976;93(5):967-970.<br />
14. H<strong>and</strong>elman SL, Leverett DH, Solomon ES, Brenner CM. Use <strong>of</strong><br />
adhesive sealants over occlusal <strong>carious</strong> <strong>lesion</strong>s: radiographic evaluation.<br />
Community Dent Oral Epidemiol 1981;9(6):256-259.<br />
15. Leverett DH, H<strong>and</strong>elman SL, Brenner CM, Iker HP. Use <strong>of</strong><br />
sealants in <strong>the</strong> prevention <strong>and</strong> early treatment <strong>of</strong> <strong>carious</strong> <strong>lesion</strong>s: cost<br />
analysis. JADA 1983;106(1):39-42.<br />
16. H<strong>and</strong>elman SL, Leverett DH, Espel<strong>and</strong> M, Curzon J. Retention <strong>of</strong><br />
sealants over <strong>carious</strong> <strong>and</strong> sound tooth surfaces. Community Dent Oral<br />
Epidemiol 1987;15(1):1-5.<br />
17. H<strong>and</strong>elman S. Therapeutic use <strong>of</strong> sealants for incipient or early<br />
<strong>carious</strong> <strong>lesion</strong>s in children <strong>and</strong> young adults. Proc Finn Dent Soc<br />
1991;87(4):463-475.<br />
18. Bjorndal L, Larsen T, Thylstrup A. A clinical <strong>and</strong> microbiological<br />
study <strong>of</strong> <strong>deep</strong> <strong>carious</strong> <strong>lesion</strong>s during stepwise excavation using long<br />
treatment intervals. Caries Res 1997;31(6):411-417.<br />
19. Magnusson BO, Sundell SO. Stepwise excavation <strong>of</strong> <strong>deep</strong> <strong>carious</strong><br />
<strong>lesion</strong>s in primary molars. J Int Assoc Dent Child 1977;8(2):36-40.<br />
20. Leksell E, Ridell K, Cvek M, Mejare I. Pulp exposure after stepwise<br />
versus direct complete excavation <strong>of</strong> <strong>deep</strong> <strong>carious</strong> <strong>lesion</strong>s in young<br />
posterior permanent teeth. Endod Dent Traumatol 1996;12(4):192-196.<br />
21. Falster CA, Araujo FB, Straffon LH, Nor JE. Indirect pulp treatment:<br />
in vivo outcomes <strong>of</strong> an adhesive resin system vs. calcium<br />
hydroxide for protection <strong>of</strong> <strong>the</strong> dentin-pulp complex. Pediatr Dent<br />
2002;24(3):241-248.<br />
22. Al-Zayer MA, Straffon LH, Feigal RJ, Welch KB. Indirect pulp<br />
treatment <strong>of</strong> primary posterior teeth: a retrospective study. Pediatr<br />
Dent 2003;25(1):29-36.<br />
23. Kreulen CM, de Soet JJ, Weerheijm KL, van Amerongen WE. In<br />
vivo cariostatic effect <strong>of</strong> resin modified glass ionomer cement <strong>and</strong><br />
amalgam on dentine. Caries Res 1997;31(5):384-389.<br />
24. Bonecker M, Toi C, Cleaton-Jones P. Mutans streptococci <strong>and</strong> lactobacilli<br />
in <strong>carious</strong> dentine before <strong>and</strong> after Atraumatic Restorative<br />
Treatment. J Dent 2003;31(6):423-428.<br />
25. Vij R, Coll JA, Shelton P, Farooq NS. Caries control <strong>and</strong> o<strong>the</strong>r<br />
variables associated with success <strong>of</strong> primary molar vital pulp <strong>the</strong>rapy.<br />
Pediatr Dent 2004;26(3):214-220.<br />
26. Farooq NS, Coll JA, Kuwabara A, Shelton P. Success rates <strong>of</strong><br />
formocresol pulpotomy <strong>and</strong> indirect pulp <strong>the</strong>rapy in <strong>the</strong> treatment <strong>of</strong><br />
<strong>deep</strong> dentinal caries in primary teeth. Pediatr Dent 2000;22(4):278-286.<br />
27. Oguntebi BR. Dentine tubule infection <strong>and</strong> endodontic <strong>the</strong>rapy<br />
implications. Int Endod J 1994;27(4):218-222.<br />
28. Black GV. A Work on Operative Dentistry. Volume 2: The Technical<br />
Procedures in Filling Teeth. Chicago: Medico-Dental Publishing<br />
Company; 1908.<br />
29. Oen KT, Thompson VP, Vena D, Caufield PW, Curro F,<br />
Dasanayake A, et al. Attitudes <strong>and</strong> expectations <strong>of</strong> treating <strong>deep</strong> caries:<br />
a PEARL Network survey. Gen Dent 2007;55(3):197-203.<br />
30. Qudeimat MA, Al-Saiegh FA, Al-Omari Q, Omar R. Restorative<br />
treatment decisions for <strong>deep</strong> proximal <strong>carious</strong> <strong>lesion</strong>s in primary<br />
molars. Eur Arch Paediatr Dent 2007;8(1):37-42.<br />
31. Black GV. A Work on Operative Dentistry. Volume 1: The<br />
Pathology <strong>of</strong> <strong>the</strong> Hard Tissues <strong>of</strong> <strong>the</strong> Teeth. Chicago: Medico-Dental<br />
Publishing Company; 1908.<br />
32. Kidd EA. How “clean” must a cavity be before restoration? Caries<br />
Res 2004;38(3):305-313.<br />
33. Bjorndal L, Thylstrup A. A practice-based study on stepwise excavation<br />
<strong>of</strong> <strong>deep</strong> <strong>carious</strong> <strong>lesion</strong>s in permanent teeth: a 1-year follow-up<br />
study. Community Dent Oral Epidemiol 1998;26(2):122-128.<br />
34. Bjorndal L, Larsen T. Changes in <strong>the</strong> cultivable flora in <strong>deep</strong> <strong>carious</strong><br />
<strong>lesion</strong>s following a stepwise excavation procedure. Caries Res<br />
2000;34(6):502-508.<br />
35. Wilder AD Jr, May KN Jr, Bayne SC, Taylor DF, Leinfelder KF.<br />
Seventeen-year clinical study <strong>of</strong> ultraviolet-cured posterior composite<br />
Class I <strong>and</strong> II restorations. J Es<strong>the</strong>t Dent 1999;11(3):135-142.<br />
36. De Munck J, Van L<strong>and</strong>uyt K, Peumans M, et al. A critical review<br />
<strong>of</strong> <strong>the</strong> durability <strong>of</strong> adhesion to tooth tissue: methods <strong>and</strong> results. J<br />
Dent Res 2005;84(2):118-132.<br />
37. Cho BH, Dickens SH, Bae JH, Chang CG, Son HH, Um CM.<br />
Effect <strong>of</strong> interfacial bond quality on <strong>the</strong> direction <strong>of</strong> polymerization<br />
shrinkage flow in resin composite restorations. Oper Dent<br />
2002;27(3):297-304.<br />
38. Lopes GC, Baratieri LN, Monteiro S Jr, Vieira LC. Effect <strong>of</strong> pos-<br />
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jada.ada.org<br />
on October 20, 2008
CLINICAL PRACTICE CRITICAL REVIEW<br />
terior resin composite placement technique on <strong>the</strong> resin-dentin interface<br />
formed in vivo. Quintessence Int 2004;35(2):156-161.<br />
39. Doi J, Itota T, Yoshiyama M, Tay FR, Pashley DH. Bonding to<br />
root caries by a self-etching adhesive system containing MDPB. Am J<br />
Dent 2004;17(2):89-93.<br />
40. Palma-Dibb RG, de Castro CG, Ramos RP, Chimello DT,<br />
Chinelatti MA. Bond strength <strong>of</strong> glass-ionomer cements to cariesaffected<br />
dentin. J Adhes Dent 2003;5(1):57-62.<br />
41. Yoshiyama M, Tay FR, Doi J, et al. Bonding <strong>of</strong> self-etch <strong>and</strong> total-<br />
712 JADA, Vol. 139 http://jada.ada.org June 2008<br />
Copyright © 2008 American Dental Association. All rights reserved.<br />
etch adhesives to <strong>carious</strong> dentin. J Dent Res 2002;81(8):556-560.<br />
42. Yoshiyama M, Tay FR, Torii Y, et al. Resin adhesion to <strong>carious</strong><br />
dentin. Am J Dent 2003;16(1):47-52.<br />
43. Allen KL, Salgado TL, Janal MN, Thompson VP. Removing <strong>carious</strong><br />
dentin using a polymer instrument without anes<strong>the</strong>sia versus a<br />
carbide bur with anes<strong>the</strong>sia. JADA 2005;136(5):643-651.<br />
44. Pashley EL, Talman R, Horner JA, Pashley DH. Permeability <strong>of</strong><br />
normal versus <strong>carious</strong> dentin. Endod Dent Traumatol 1991;<br />
7(5):207-211.<br />
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jada.ada.org<br />
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Deep or partial caries removal: which is best?<br />
In <strong>deep</strong> <strong>carious</strong> <strong>lesion</strong>s, should all infected <strong>and</strong> affected dentine be removed<br />
prior to restoration?<br />
Thompson V, Craig RG, Curro FA, Green WS, Ship JA.<br />
Treatment <strong>of</strong> <strong>deep</strong> <strong>carious</strong> <strong>lesion</strong>s by complete excavation or partial<br />
removal. A critical review. J Am Dent Assoc 2008; 139:705–712<br />
Data sources Searches for studies were made using <strong>the</strong> databases:<br />
Medline, Evidence-based Medicine Reviews, Cochrane Database <strong>of</strong><br />
Systematic Reviews, Cochrane Central Register <strong>of</strong> Controlled Trials <strong>and</strong><br />
OVID’s Database <strong>of</strong> Abstracts <strong>of</strong> Reviews <strong>of</strong> Effects.<br />
Study selection Only studies reported in English with human<br />
participants were included. R<strong>and</strong>omised controlled trials (RCT) <strong>and</strong><br />
relevant observational studies were included. No o<strong>the</strong>r inclusion or<br />
exclusion criteria are described.<br />
Data extraction <strong>and</strong> syn<strong>the</strong>sis A formal data extraction process<br />
is not described <strong>and</strong> a qualitative description <strong>of</strong> <strong>the</strong> included studies<br />
is provided.<br />
Results Ten articles reporting six studies were included. The results <strong>of</strong><br />
three RCT, one with a followup period <strong>of</strong> 10 years, provide evidence supporting<br />
<strong>the</strong> practice <strong>of</strong> leaving behind infected dentine, <strong>the</strong> removal <strong>of</strong><br />
which would risk pulp exposure. A number <strong>of</strong> o<strong>the</strong>r studies show that<br />
cariogenic bacteria, once isolated from <strong>the</strong>ir source <strong>of</strong> nutrition by a<br />
restoration <strong>of</strong> sufficient integrity, ei<strong>the</strong>r remain dormant or die <strong>and</strong> thus<br />
pose no risk to <strong>the</strong> health <strong>of</strong> <strong>the</strong> dentition.<br />
Conclusions There is substantial evidence that, for caries management,<br />
it is not necessary to remove all vestiges <strong>of</strong> infected dentin from<br />
<strong>lesion</strong>s approaching <strong>the</strong> pulp.<br />
Address for correspondence: Dr R Craig, Department <strong>of</strong> Basic Sciences <strong>and</strong><br />
Crani<strong>of</strong>acial Biology, New York University College <strong>of</strong> Dentistry, 345 East 24th<br />
Street/ 1001S, New York NY 10010-4086, USA. E-mail: rgc1@nyu.edu<br />
SUMMARY REVIEW/RESTORATIVE DENTISTRY<br />
Commentary<br />
Since <strong>the</strong> days <strong>of</strong> GV Black, complete caries removal has been<br />
regarded as <strong>the</strong> gold st<strong>and</strong>ard in cavity preparation <strong>and</strong>, despite<br />
<strong>the</strong> lack <strong>of</strong> evidence to support this approach, it remains common<br />
practice today. In <strong>deep</strong> cavities, <strong>the</strong> <strong>carious</strong> process itself <strong>and</strong><br />
<strong>the</strong> trauma <strong>of</strong> such radical caries removal can cause detrimental<br />
inflammatory changes within <strong>the</strong> pulp. If such caries removal<br />
leads to exposure <strong>of</strong> a vital pulp, a direct pulp cap, commonly<br />
using calcium hydroxide, is considered. Although most research<br />
on <strong>the</strong> direct pulp cap has focussed on <strong>the</strong> favourable outcome for<br />
traumatically exposed pulps which are healthy prior to <strong>the</strong> injurious<br />
incident, <strong>the</strong> prognosis following a <strong>carious</strong> exposure is not<br />
good: 5- <strong>and</strong> 10-year success rates <strong>of</strong> 37% <strong>and</strong> 13% respectively<br />
have been reported. 1 This critical review is <strong>the</strong>refore appropriate,<br />
with its systematic search <strong>of</strong> <strong>the</strong> literature for evidence that might<br />
elucidate whe<strong>the</strong>r complete caries removal <strong>and</strong> its concomitant<br />
complications is necessary.<br />
Carefully designed prospective RCT provide <strong>the</strong> strongest evidence<br />
for any intervention. Such trials were <strong>the</strong> focus <strong>of</strong> our 2006 Cochrane<br />
review 2 comparing complete or ultraconservative caries removal. The<br />
authors <strong>of</strong> this paper are correct, however, to draw attention to <strong>the</strong><br />
fact that studies <strong>of</strong> a different design can also add to our underst<strong>and</strong>ing<br />
<strong>and</strong> can <strong>of</strong>ten provide compelling evidence for an intervention.<br />
Not including such studies may be regarded by some as “throwing<br />
<strong>the</strong> baby out with <strong>the</strong> bathwater”. The aim here was <strong>the</strong>refore to<br />
extend <strong>the</strong> search <strong>and</strong> look for additional studies comparing complete<br />
or partial caries removal. In addition to two RCT included in<br />
<strong>the</strong> Cochrane review, four fur<strong>the</strong>r studies were found, specifically<br />
three observational studies <strong>and</strong> one more RCT.<br />
The main aim <strong>of</strong> <strong>the</strong> additional RCT was to investigate <strong>the</strong> cariostatic<br />
effect <strong>of</strong> black copper cement when partial caries removal<br />
was carried out in primary teeth. In <strong>the</strong> partial caries removal group,<br />
<strong>the</strong> durability <strong>of</strong> glass ionomer restorations lined with black copper<br />
cement was poor, but glass ionomer restorations alone performed as<br />
well following partial caries removal as <strong>the</strong>y did following complete<br />
caries removal.<br />
Of <strong>the</strong> three observational studies included here, two were stepwise<br />
excavation in all but name. 3,4 Although o<strong>the</strong>r similar clinical studies<br />
on stepwise excavation were not included in <strong>the</strong> main results <strong>of</strong> this<br />
paper, <strong>the</strong>y were mentioned in <strong>the</strong> text (those cited in <strong>the</strong> Cochrane<br />
review 1 <strong>and</strong> <strong>the</strong> review by Bjørndal <strong>and</strong> Larsen, 2005). Three <strong>of</strong> <strong>the</strong>se<br />
studies showed that caries that is left <strong>and</strong> sealed into <strong>the</strong> tooth after<br />
partial caries removal appears to arrest, so that when <strong>the</strong> cavities<br />
are re-entered <strong>the</strong> number <strong>of</strong> viable organisms within <strong>the</strong> <strong>lesion</strong>s is<br />
significantly reduced. 3–5<br />
The final study included looked at <strong>the</strong> success <strong>of</strong> indirect pulp caps<br />
in primary molar teeth using ei<strong>the</strong>r a calcium hydroxide lining material<br />
or resin-modified glass ionomer. The success rates presented at<br />
4 years were 89% <strong>and</strong> 93%, respectively.<br />
www.nature.com/ebd 71
RESTORATIVE DENTISTRY<br />
Although partial caries removal may sit uncomfortably with some<br />
dentists, <strong>the</strong> authors <strong>of</strong> this paper also describe a series <strong>of</strong> studies in<br />
which occlusal caries is arrested by simply fissure-sealing <strong>the</strong> <strong>lesion</strong>s<br />
with no caries removal at all. O<strong>the</strong>r studies are described that add fur<strong>the</strong>r<br />
weight to <strong>the</strong> partial caries removal argument. These all show<br />
that by depriving <strong>the</strong> organisms within <strong>lesion</strong>s <strong>of</strong> <strong>the</strong> intra-oral<br />
substrate <strong>the</strong>y require to survive, both <strong>the</strong> number <strong>and</strong> diversity <strong>of</strong><br />
organisms decline, with only those able to metabolise pulpal serum<br />
proteins surviving. 6 These organisms are not associated with active<br />
<strong>carious</strong> <strong>lesion</strong>s, <strong>and</strong> even pulpal nutrients will decline with time<br />
because <strong>of</strong> pulp-dentine complex reactions <strong>of</strong> tubular sclerosis <strong>and</strong><br />
reactionary dentine formation.<br />
Unfortunately, it is not clear from this review, or <strong>the</strong> original<br />
papers, what constitutes <strong>deep</strong> caries or partial caries removal. Some<br />
authors have described <strong>lesion</strong>s reaching up to halfway to <strong>the</strong> pulp,<br />
determined on a radiograph, whereas o<strong>the</strong>rs have given little specific<br />
information o<strong>the</strong>r than saying <strong>the</strong> <strong>lesion</strong> is <strong>deep</strong>, or adding that <strong>the</strong><br />
extent means pulpal exposure is likely if caries is completely removed.<br />
Similarly, partial caries removal varies from simply bevelling enamel<br />
at <strong>the</strong> entrance to <strong>the</strong> fissure to carrying out only peripheral caries<br />
removal <strong>and</strong> leaving s<strong>of</strong>t infected <strong>carious</strong> dentine pulpally; to removal<br />
<strong>of</strong> caries until firm, stained dentine is reached <strong>and</strong> <strong>the</strong>n placement<br />
<strong>of</strong> an indirect pulp cap.<br />
The studies cited are <strong>the</strong>refore heterogeneous, but <strong>the</strong> evidence<br />
stemming from <strong>the</strong>m all is that removal <strong>of</strong> all <strong>carious</strong> tissue is not<br />
necessary. In light <strong>of</strong> <strong>the</strong> substantial evidence cited to support partial<br />
caries removal, <strong>the</strong> authors <strong>of</strong> this paper point out that <strong>the</strong>re<br />
have, as yet been no studies to prove <strong>the</strong> desirability <strong>of</strong> removing all<br />
infected dentine. They conclude that, “before this concept (<strong>of</strong> partial<br />
removal) is generally accepted by <strong>the</strong> pr<strong>of</strong>ession additional clinical<br />
trials may be needed”. This, I am sure, is true. These trials should<br />
be carried out in primary care with detailed, specific information on<br />
<strong>lesion</strong> extent <strong>and</strong> what constitutes partial caries removal. The success<br />
<strong>of</strong> such interventions also needs to be assessed along with research<br />
into techniques for monitoring sealed caries.<br />
David Ricketts<br />
Department <strong>of</strong> Restorative Dental Care <strong>and</strong> Clinical Dental<br />
Sciences, University <strong>of</strong> Dundee Dental School, Dundee, Scotl<strong>and</strong>, UK<br />
1. Bar<strong>the</strong>l CR, Rosenkranz B, Leuenberg A, Roulet JF. Pulp capping <strong>of</strong> <strong>carious</strong> exposures:<br />
treatment outcome after 5 <strong>and</strong> 10 years: a retrospective study. J Endod 2000;<br />
26:525–528.<br />
2. Ricketts DN, Kidd EA, Innes N, Clarkson J. Complete or ultraconservative removal <strong>of</strong><br />
decayed tissue in unfilled teeth. Cochrane Database Syst Rev 2006; issue 3.<br />
3. Maltz M, de Oliveira EF, Fontanella V, Bianchi R. A clinical, microbiologic, <strong>and</strong><br />
radiographic study <strong>of</strong> <strong>deep</strong> caries <strong>lesion</strong>s after incomplete caries removal.<br />
Quintessence Int 2002; 33:151–159.<br />
4. Fairbourn DR, Charbeneau GT, Loesche WJ. Effect <strong>of</strong> improved Dycal <strong>and</strong> IRM on<br />
bacteria in <strong>deep</strong> <strong>carious</strong> <strong>lesion</strong>s. J Am Dent Assoc 1980; 100:547–552.<br />
5. Bjørndal L, Larsen T. Changes in <strong>the</strong> cultivable flora in <strong>deep</strong> <strong>carious</strong> <strong>lesion</strong>s following<br />
a stepwise excavation procedure. Caries Res 2000; 34:502–508.<br />
6. Paddick JS, Brailsford SR, Kidd EA, Beighton D. Phenotypic <strong>and</strong> genotypic selection<br />
<strong>of</strong> microbiota surviving under dental restorations. Appl Environ Microbiol 2005;<br />
71:2467–2472.<br />
Evidence-Based Dentistry (2008) 9, 71-72. doi:10.1038/sj.ebd.6400592<br />
72 © EBD 2008:9.3