Background information
Dr. Christian Ramel:
Hard tissue augmentation utilizing guided bone regeneration (GBR) has become the treatment
option to provide optimal bone support for osseointegrated dental implants in case of bony defects. Implants placed in demineralized bovine bone mineral (DBBM) and collagen membranes
regenerated bone do not perform differently from implants placed in native bone with respect to
implant survival, marginal bone height and peri-implant soft-tissue parameters1. For years though,
non-resorbable membranes made of expan ed PTFE have been considered as gold standard, esped
cially in larger defect situations like the one presented below. This is no longer true, since resorbable membranes such as Geistlich Bio-Gide® have been used for over 15 years by now and they
have proven their success in every day clinics and in literature. A recent study investigated the
long-term outcome of implants with GBR using resorbable (collagen) and non-resorbable (ePTFE)
membranes. The authors found no difference in implant survival after 12-14 years with respect to
the type of membranes utilized2. The major advantages of resorbable membranes are a facilitated
clinical handling during application, fewer wound dehicences3,4 and no need for surgical membrane
removal. On the other hand, stabilization of the augmentation material is limited, since this type
of membrane is not rigid. Therefore, over-augmentation of the site is often indicated. In addition,
reducing soft-tissue pressure by performing releasing incisions of the periosteum may be required.
Fig. 10 In horizontal aspect, a major bony defect is
visible. The ridge measures about 2 mm in width in
the central region.
Fig. 11 To enable a perfectly prosthodontically
driven implant position, the implant position was
determined with a conventional splint. By not placing
the implant in a central location, wider bucco-oral
dimensions were found.
Fig. 12 The implant shoulder was positioned 2 mm
apical of the future crown margin, leaving a periimplant defect of 3 mm.
Fig. 13 Geistlich Bio-Gide® was adapted, apically
positioned underneath the mucoperiosteal flap and
deflected, then Geistlich Bio-Oss® Collagen was
carefully put onto the defect region. The aim was
to over ugment the site, since considerable softa
tissue pressure was to be expected.
Fig. 14 The collagen membrane was then laid over
the implant, and tucked underneath the lingual
mucosa.
Fig. 15 To enable perfect wound margin adapation
without tension, the periosteum was cut on the
buccal side. Because of the rather large augmentation the implant was left to heal submucosally. Sutures
were performed with single knots made out of ePTFE.
Postoperatively the patient rinsed with chlohexi [