Background information
3. Surgical procedure
Dr. Dietmar Weng:
Directly after tooth extraction, alveolar sockets of single- and multirooted teeth present the dentist working in implantology with several problems. In molar alveoli, the prosthetically correct
implant position is in the region of the interradicular septa. However, the drilling procedures required for creating the implant osteotomy are difficult in this region and frequently lead to loss of
the septa. If this is the case, primary stability can only be achieved beyond the alveolar floor in the
remaining millimetres above the inferior alveolar nerve or below the maxillary sinus floor. After
implantation in the molar region, the question is furthermore, what to do with the remaining gap
between implant and alveolar wall. Moreover, closed healing is possible only in the rarest of cases,
unless one is willing to accept large flaps and extensive periostal slitting for primary closure of the
alveolus. Instead, gingiva formers are in most cases screwed onto the implant for open healing,
which in turn means that higher requirements with regard to primary stability must be met. In
single-rooted alveoli, the implant osteotomy must be performed along the oblique plane of the
oral alveolar wall in order to be able to position the implant slightly more oralwards. This is necessary due to the microgap activity of most implant systems1, and in order to create a fillable compensatory space between implant and vestibular alveolar wall to make up for the vertical component of post-extractional bundle bone loss along the thin vestibular alveolar wall2. The purpose of
this vestibular “air bag” is to prevent hard and soft tissue recession later on.
If these challenges to a three-dimensionally successful immediate implantation in prosthetically
correct position are to be avoided, or if the residual alveoli are too defective or inflamed for immediate implantation, ridge preservation must be considered3. In defective alveoli (> 1.5 mm height
loss in one or more alveolar walls and/or presence of apical fenestration, e.g. due to previous root
tip resection), ridge preservation as in the case described here is performed. The procedure for
intact alveoli is identical, except that no membrane is required because four walls are present.
Fig. 1 Tooth 46 had been fitted with a full cast
crown following endodontic treatment. Clinical
examination revealed significantly increased mesiobuccal probing depths.
Fig. 2 A region with markedly decreased radiopacity can be seen along the mesial root. After
consulting with the endodontist, the tooth was
assessed as not worth preserving due to suspected
longitudinal fracture.
Fig 3 After removal of the crown and buccolingual separation, the two halves of the tooth were
removed atraumatically from the alveolus.
Fig. 16 The postoperative radiograph shows an
adequate safety distance to the inferior alveolar
nerve as well as the still ongoing ossification in the
region of the former alveolar parts.
Fig. 17 Wound healing 1 week after implantation.
Fig. 18 Status 4 months after implantation on the
day of implant exposure.
Fig. 4 The longitudinal fracture of the mes ial root
was confirmed when the tooth was extracted.
Fig. 5 The mesio-buccal gingiva height as measured
with a probe placed on the remaining alveolar wall
was 10 mm, i.e. the vertical loss of alveolar wall was
7 mm.
Fig. 6 The periosteum was lifted off the buccal
bone wall over a vertical stretch of 3-4 mm using a
blunt micro-raspatory, and a Geistlich Bio-Gide®
membrane was inserted into the space between the
periost and the alveolar wall.
Fig. 19 A single-component sulcus former was
screwed on after minimally invasive exposure.
Fig. 20 The single-tooth radiograph taken immediately after exposure shows the radiologically
osseointegrated implant with more advanced
ossification of the peri-implant hard tissue.
Fig. 21 Status of the soft tissue funnel 4 weeks
after implant exposure on the day of fitting of the
superstructure.
Fig. 7 The alveolar space was filled up with Geistlich
Bio-Oss® Collagen. Condensing of the material right
into the apical root areas was not performed.
Fig. 8 The open part of the Geistlich Bio-Gide®
membrane was inserted lingually between the
periosteum and the alveolar wall.
Fig. 9 A gelatine sponge was placed on the Geistlich
Bio-Gide® membrane and secured in position with a
horizontal cross suture for initial crestal wound closure.
Fig. 22 Individual CAD/CAM titanium post screwed
onto the implant with 15 Ncm.
Fig. 23 VMK crown after being cemented onto the
implant post.
Fig. 24 The buccal view reveals that the soft tissue
boundary in the central buccal region is higher than
before the tooth was extracted.
Fig. 10 Status at suture removal 6 days after ridge
preservation treatment.
Fig. 11 Status 4 weeks after ridge preservation treatment.
Fig. 12 Status on the day of implantation 6 months
after ridge preservation treatment.
Fig. 25 Single-tooth radiograph after crown cementation to check for excess cement.
Fig. 13 Ridge incision reveals a horizontally very
well preserved ridge. The original mesio-buccal
dehiscence defect has been regenerated.
Fig. 14 An Ankylos C/X implant measuring 4.5 x 9.5 mm
was inserted. After insertion, a bone wall 1.5 mm thick
was present on the buccal side of the implant.
Fig. 15 The flaps could be closed again tension-free
with a two-row suture closure without periostal
slitting.
Medication used:
Clindamycin (2 x 600 mg for 7 days), ibuprofen (2 x 600 mg for 3 days), chlorhexidine digluconate
0.1% (twice daily for 4-6 weeks)
2. Treatment objectives
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The aim of ridge preservation therapy is to completely transform the alveolar inner space still
present at extraction into a hard-tissue implant bed with minimal surgical intervention and without
flap formation, and furthermore to regenerate the already missing alveolar portions by applying the
GBR technique.
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