EDI - European Association of Dental Implantologists

70 EDI
Case Studies
were also required to refrain from wearing a denture
for at least two weeks after implant placement to
facilitate soft-tissue healing [25]. After the submerged
healing period, a second intervention to uncover the
implants was required. The original concern was that
any implant micromovement might lead to fibroustissue
encapsulation of the implant as a reparative
response to physical trauma, resulting in failure to
achieve osseointegration [53-55]. While the importance
of the contribution by Brånemark and coworkers
[25] should not be underestimated given the high
success rates and predictable results that have been
documented for more then 30 years, it is important to
note that delayed loading was an empirical principle
that had never been experimentally demonstrated.
The current trend is not to consider implant movement
per se as detrimental to osseointegration, but
rather to consider a threshold of acceptable micromovement.
It has been suggested that micromovement
of 150 μm or more is excessive and therefore
deleterious for osseointegration, while micromovement
of less of 50 μm seems to be tolerated [53-55].
During the 1970s, Ledermann [31] introduced the technique
of immediately splinting and loading four
transmucosal implants in the edentulous mandible
with a bar-supported overdenture. The underlying
theory was that rigid splinting of implants in the
dense bone of the mandibular symphysis would prevent
implant micromovement and allow effective
healing and osseointegration under immediate-loading
conditions. Since then, an increasing number of
publications on immediate loading have been published
citing high success rates in mandibular and
maxillary sites for single-tooth replacement, partial
fixed restorations and full-arch prostheses [31-52].
Most authors agree that good bone quality, primary
stability with insertion torques up to 35-40 Ncm
and rigid splinting of implants are important factors
for the long-term survival of implants [45]. Several
studies by Piattelli and coworkers [41-43] on both animals
and humans have demonstrated that not only
may immediate loading lead to successful osseointegration,
but it may also increase the quantity of bone
in direct contact with the implant surface.
The dense structure of cortical calvarial bone grafts
[21-24], which gives implants a high level of primary
stability, and the immediate rigid splinting of fixtures
with a screw-retained provisional restoration
allowed us to immediate load implants inserted in
previously grafted maxillary sites. The Teeth-in-an-
Hour concept along with the Procera 3D planning
software (Nobel Biocare AB, Gothenburg, Sweden)
allowed us to provide patients with fixed well-functioning
restorations on implants in a single one-hour
procedure. By using a custom template created from
the primary CT scan, the provisional teeth can be fabricated
before the implant procedure and inserted at
the same time the implants are placed [58-62]. This
system offers more accurate and safer positioning of
dental implants via flapless surgery, reducing postoperative
pain, oedema and bleeding [58-62].
Conclusions
The clinical results reported here have shown that
immediate loading is feasible even in grafted anterior
maxillary sites, shortening treatment times in
patients with bone defects.
The therapy is a clinical option even in correctly
diagnosed patients with inadequate bone structure,
provided that a proper reconstructive treatment plan
is made. Patients expect good aesthetic results as
much as they expect functional rehabilitation.
Implant treatment in the aesthetic zone following
injuries or the resection of a tumour present both
aesthetic and functional challenges and require the
use of the entire scientific, biological and technological
armamentarium, from diagnosis to final therapy.
An accurate CT scan showing the available bone
supply plus the correct identification of viable
implant positions using state-of-the-art diagnostic
software constitute an appropriate approach toward
a three-dimensional determination of the bone
quantity required for the implants and their superstructures.
Decisions related to harvesting, donor
sites and bone-block sizes can be made subsequent
to the virtual planning phase.
A computer driven approach seems to be a new
“gold standard” for implant placement, as it assists in
identifying the correct position of the implant and
prosthetic platform, respecting adjacent anatomical
structures and creating a correct emergence profile of
the final restorations. In addition, this clinical approach
offers an opportunity to perform a safe and accurate
flapless procedure with favourable outcomes.
The use of cortical multi-layered split calvarial bone
grafts with a very low resorption rate and highly dense
structure, high primary stability and rigid connection of
the implants and accurate computer-guided planning
and implant insertion are the keys to success. However,
more studies and randomized clinical trials are needed
to asses the predictability of the procedure.
Contact Address
Dr Alessandro Acocella
Via Dante da Castiglione, 16/A Cercina, Sesto Fiorentino,
Firenze, 5010, ITALY
Phone: +39 333 2317982 (cell.)
alessandroacocella@yahoo.it
A list of references
will be supplied by
the editorial office
on request.