Clinical outcome of autogenous bone blocks or guided bone regeneration with e‐PTFE membranes for the reconstruction of narrow edentulous ridges

Abstract

The aim of this study was to analyse the clinical outcome of two different surgical methods for the reconstruction of narrow edentulous ridges before implant installation: guided bone regeneration with e-PTFE membranes and autologous bone chips or grafting of autologous bone blocks without e-PTFE membranes. Thirty partially edentulous patients, presenting insufficient bone width (less than 4 mm) in the edentulous sites for installation of screw-type titanium implants, were selected and assigned to two different treatment modalities. Fifteen patients (group 1) were treated by means of guided bone regeneration with e-PTFE membranes supported by stainless steel screws and autologous bone chips taken from intraoral sites. Fifteen patients (group 2) were treated by means of autologous bone blocks taken from intraoral or extraoral sites (anterior iliac crest and calvaria) and stabilized with titanium microscrews. Six to 8 months later, during re-entry for implant insertion, the gain of ridge width obtained was measured. In group 1 the average amount of bone gain was 2.7 mm, whereas in group 2 the value was 4.0 mm. Five to 6 months after implant placement prosthetic rehabilitation was started. The mean follow-up after prosthetic load has been 22.4 months. Success rates of implants according to Albrektsson criteria has been 93.3% in group 1, and 90.9% in group 2. Although a statistical comparison between the two treatment modalities may not be feasible, due to the bias resulting from the choice of treatment by the clinician and from the differences in donor sites and defect extension, some considerations can be made: 1) both methods are a reliable means for the correction of narrow edentulous ridges; 2) both techniques necessitate overcorrection of the defect because of interposition of connective tissue beneath the membrane in the first group and bone resorption in the second one; 3) the use of semipermeable barriers increases the costs of the surgical procedure, as compared to bone grafting without membranes; 4) guided bone regeneration presents a higher risk of infection because of wound dehiscence and membrane exposure. Therefore, in case of wide edentulous areas, reconstruction of narrow ridges should be performed with bone blocks without membranes.

Guided bone regeneration using a hydrophilic membrane made of unsintered hydroxyapatite and poly(L-lactic acid) in a rat bone-defect model

“…Membranes used for GBR include those made of nonresorbable materials, such as nitrocellulose or expanded polytetrafluoroethylene (e-PTFE); however, these membranes require surgical removal after bone augmentation [8][9][10][11][12][13] . Thus, resorbable GBR membranes are more desirable.…”

Treatment planning of implants in posterior quadrants

“…Due to advances in bone augmentation techniques, sinus floor elevation and distraction osteogenesis virtually no limits exist to placement of implants. [6][7][8] The broad use of implants in posterior quadrants is not exclusively based on favourable long term reports; [3][4][5] other factors such as biomechanical advantages and the availability of prefabricated components have made this treatment modality appealing to the clinician.…”

“…Advances in onlay grafting, distraction osteogenesis and maxillary sinus augmentation allow the surgeon to place implants in sites which were previously contraindicated. [6][7][8] Sinus augmentation provides adequate bone volume to place implants but does not correct for vertical space deficiencies (Figs 35-36). The patient must be aware that prosthetically, long teeth with root form or pink porcelain will be required (Fig.…”

The Use of Cancellous Bone-Block Allograft for Reconstruction of the Atrophic Alveolar Ridge

“…Block grafts were indicated for bony deficiencies measuring at least 3 mm horizontally and up to 3 mm vertically on computed tomography (CT) para-axial reconstruction, as recommended (Chiapasco et al, 1999). Surgery was performed under local anesthesia.…”