Physical and chemical aspects of saliva as indicat... - ResearchGate

dence that other electrolytes have any role in establishing
an increased risk for caries. 10,12,24,45,46,69 There is also
little to no evidence that salivary small molecules have
any role in establishing an increased risk for caries.
12,16,24,30,45,46,50,69,70,71,72 Interpretation of this information
is complicated, however, by the wide range of reported
measurements for these components in saliva.
Salivary immunoglobulins. Twenty-two studies
examined the relation between salivary immunoglobulins
and caries status. 12,16,29,30,45,46,50,73-87 The levels of specific
sIgA showed a modest inverse relationship with
caries risk, and the literature is nearly equally divided
for and against an anticaries role of specific sIgA. Seven
studies reported an inverse relationship between specific
sIgA antibodies in saliva (for example, anti-S.
mutans sIgA) and caries status, 74,79,81-85 while two studies
reported that caries was related to increased levels of
specific sIgA 80,86 and five studies reported no relationship
between specific sIgA immunoglobulins and caries.
16,29,30,77,87 With one exception, these reports examined
subjects who were healthy or had medical
conditions not directly related to immunoglobulin deficiency.
30 The levels of total sIgA, in contrast to specific
sIgA, were found not to be good risk indicators.
Although IgG and IgM may be compensatory in sIgA
deficient subjects, there is insufficient evidence to establish
a role for these immunoglobulins in caries risk.
Salivary innate non-immunoglobulin factors.
Fourteen studies examined the relationship between
caries and one or more of the following salivary factors:
total protein, acidic or basic proline-rich proteins
(PRPs), statherins, histatins, peroxidase/
myeloperoxidase, lysozyme, lactoferrin, amylase, sucrase
activity, salivary glycoconjugates,
and bacteria-aggregating glycoproteins
(BAGPs). 10,12,24,29,30,40,45,46,50,58,69,83,88,89 Virtually all these
studies found no relationship with caries status.
Sjögren’s syndrome and associated conditions.
Three studies evaluated both primary (pSS) and secondary
(sSS) forms of Sjögren’s disease, 1,8,90 and two
studies evaluated subjects having only pSS. 10,11 Both
pSS and sSS were found to be unequivocally associated
with increased caries risk, which was exclusively
due to the pathologically decreased flow rate observed
in Sjögren’s patients. Neither pSS nor sSS subjects had
any discernible alterations in mean salivary pH or buffer
capacity, and these were not associated with caries risk
in the studies. Scleroderma is a connective tissue disorder
associated with sSS, and one additional study
found a relationship between scleroderma-related xerostomia
and caries prevalence. 91
Radiation, chemotherapy, and surgery. Five
studies examined subjects who had received only chemotherapy
without any radiation to the jaws, 34,43,58,60,75
and two studies examined subjects who had received a
combination of chemotherapy and total body irradiation
(that is, bone marrow transplant patients). 23,37 No
evidence was found for an association between caries
and chemotherapy or total body irradiation. With respect
to local radiation damage of the head and neck
area, the literature contains sparse evidence based on
controlled clinical studies having adequate sample size;
much stronger associations come from descriptive studies
and individual case reports, which were excluded
here. One study reported equivocal findings on the effects
of surgical retropositioning of sublingual salivary
ducts (sialodochoplasty), 62 and no studies examined surgery
to the salivary glands per se.
Use of medications having xerostomic side effects.
Although somewhat limited, the evidence reported
here continues to support the belief that certain medications
that have xerostomic side effects may lead to an
increased risk of caries. 12,13,92,93 This risk results from
chronically lowered salivary flow rate rather than other
alterations in saliva, for example, poor buffering capacity.
It is important to note that none of the studies
measured the effect of discontinuing medication on
salivary output, so that these findings could be inaccurate
regarding the “increased risk” for dental caries.
Other conditions. A number of articles attempting
to correlate caries with salivary disturbances in several
other conditions were also found. These included
both insulin- and noninsulin-dependent diabetes,
35,39,51,52,54,94 anorexia and bulimia, 9,17,53,63 chronic
malnutrition, 7 Crohn’s disease, 50 cleft lip and cleft palate,
2 various heart conditions, 32,35,76 chronic renal failure,
27 common variable immunodeficiency, 30
asthma, 12,31,69,93 Down’s syndrome and non-Down’s mental
retardation, 95,96 spinal cord injury, 14 and thalassemia
major. 46 None of these articles provided convincing evi-
Table 2. Summary of the evidence according to the strength of association between salivary characteristics and
caries risk
Strong Association Weak-to-Moderate No Association
with Caries Risk Association with Caries Risk with Caries Risk
Flow Rate Buffering Capacity; Calcium/Phosphate; pH (static measurement); Glucose Clearance
Specific sIgA Immunoglobulin
Rate/Concentration; Other Electrolytes & Small
Organic Molecules; Total sIgA; IgG, IgM, Innate
Immunity Factors
October 2001 ■ Journal of Dental Education 1057