Conditions for success in guided bone regeneration: retrospective study on 376 implant sites.

BACKGROUND: Used alone or in association with bone, guided bone regeneration is a clinically accepted method to increase the volume of bone during implant placement. Concerns about appropriate surgical techniques and the predictability of the results questions still exist. The aim of this study was to assess the conditions for success. METHODS: Three-hundred-seventy-six implants were placed in association with 214 non-resorbable membranes. In 109 implants, the membrane was secured on a blood clot; for 213 implants, membrane was placed with autogenous bone; and for 54 implants it was placed with allogenic bone. The surgical procedure, the primary closure, the timing of re-entry, and the density of regenerated tissue were studied. RESULTS: In 19 membranes, barrier exposure occurred before 3 months in these instances, the regenerated tissue was removed; another 7 membranes were exposed between 3 and 6 months. The 188 non-exposed membranes were removed between 6 and 12 months. In cases of exposure before 3 months, the regenerated tissue was soft and then removed. After closure for 6 months or more, the regenerated tissue was dense and resistant to probe pressure. The best results were obtained when the membranes were placed with autogenous bone. CONCLUSIONS: If all the clinical steps are appropriately followed, guided bone regeneration using an autogenous bone graft and implant placement is a predictable technique for increasing bone volume.

Clinical evaluation of guided bone regeneration at exposed parts of Brånemark dental implants with and without bone allograft.

This investigation evaluated guided bone regeneration with a polytetrafluoroethylene barrier membrane at exposed parts of Brånemark dental implants with and without concomitant use of decalcified freeze-dried bone allograft. Density of the regenerated tissue was also determined using a No. 23 probe at a pressure of 25 g and was graded from 1 to 5. The higher index was associated with a higher resistance of newly formed tissue to the pressure of the probe. In 19 patients, 23 defects were treated by barrier membrane alone and 11 defects by bone allograft with barrier membrane. The width and the depth of the defects were determined at the time of the implant placement and at the second-stage implant surgery. When success was defined as 0 mm of residual defect, the mean success rate was 68% for the membrane group and 90% for the membrane group with bone allograft, with no statistically significant difference between the two treatment groups. The two groups did not demonstrate a significant difference in median density index. There was a significant positive relationship between time of membrane coverage and density index. A density index of 4 was only recorded after 7 months of membrane coverage. The present findings suggest beneficial clinical effect with the use of membrane alone and freeze-dried bone allograft with membrane for guided bone regeneration. This study proposed the use of a novel density index for clinical evaluation of regenerated tissue.

[Periodontal reconstruction using the guided tissue regeneration technique. Apropos of a case]. / Reconstruction parodontale par la technique de la régénération tissulaire guidée. A propos d'un cas.

Different surgical techniques have been used to treat periodontal osseous defects. Periodontists were very full of hope with osseous grafts but the results were disappointing or unpredictable. A best knowledge of the biologics determinants of periodontal healing has lead to the concept of guided regeneration. A case of deep osseous defect of a mandibular incisor was treated by the placement of a Gore Tex membrane. The clinical and radiographic result is satisfactory.

Repair potential in localized juvenile periodontitis. A case in point.

An aggressive form of localized juvenile periodontitis (LJP) in a 12-year old West African female is reported. The case was treated with scaling, root planing, debridement, and tetracycline therapy, which resulted in complete resolution of the disease, including elimination of periodontal inflammation, regeneration of lost periodontal structures, and spontaneous repositioning of teeth that had pathologically migrated. A hopelessly involved mandibular right first molar was successfully replaced by an incompletely developed maxillary third molar tooth bud whose roots and pulp structure continued to develop after autotransplantation. It is suggested, that LJP can be successfully treated without periodontal surgery and that the potential for repair in LJP cases is apparently greater than what one can anticipate in adult forms of periodontitis.

[Function of polynuclear neutrophils in patients with juvenile periodontitis and rapidly progressing periodontitis]. / Fonction des polynucléaires neutrophiles chez des patients atteints de parodontite juvénile et de parodontite à progression rapide.

It is generally assumed that early onset forms of periodontal disease (including Juvenile and Rapidly Progressive Periodontitis) are associated with a defect in neutrophil behaviour. We have investigated neutrophil functions in patients with Juvenile (J.P.) and Rapidly Progressive Periodontitis (R.P.P.). In the group of J.P. patients the directed mobility (FMLP and zymosan activated plasma) is significantly decreased. The superoxide generation in response to FMLP decreases while the PMA response is normal. In the group of R.P.P. patients no significant abnormality has been reported.

[Guided tissue regeneration: clinical and microscopic study]. / Régénération tissulaire guidée: étude clinique et microscopique.

A case of furcation involvement of a maxillary molar is reported. The treatment consisted in applying the concept of Controlled Tissue Regeneration using a Goretex membrane. After removal of the membrane the result is satisfactory. The membrane is then examined under transmission electronic microscope. The lateral aspect of the membrane (in contact with the proliferating epithelial tissue) show a marked bacterial proliferation.

[Histological study of periodontal healing of surgically displaced human teeth]. / Etude histologique de la cicatrisation parodontale de dents humaines déplacées chirurgicalement.

Mandibular incisors had to be extracted on a 52 years old patient. The aim of this investigation was to study, the periodontal healing of teeth surgically displaced after bone resections (alveolar, buccal and apical). 3 years later, the teeth were extracted and treated for microscopic observation. No new attachment was seen on the curetted roots, except where the periodontal ligament had been preserved. The concept of cellular sociology was suggested to explain the sites of radicular resorption. An hypothesis was then put forward: epithelial formations present in the periodontal ligament are not of an embryologic origin (Malassez debris) but are issued from the migration of epithelial cords during new formation of the junctional epithelium.

[Cellular competition and healing]. / Compétition cellulaire et cicatrisation.

Different therapeutic solutions have been tried to obtain a new attachment. Several animal experiments have studied cellular colonization of radicular surfaces exposed to the disease then planed. Only the cells from the periodontal ligament seem to be able to form a new attachment. The interposition of a membrane seem to prevent gingival and osseous tissues to interfere with the periodontal ligament. The periodontal ligament cells colonize then the radicular surface.

[Current therapy of gingival recession]. / Thérapeutique actuelle des récessions gingivales.

The muco-gingival surgery represents one of the facet of periodontal surgery. The gingival recessions, characterized by a total attachmentless uncovering the root surface, become an esthetic and painful problem for our patients. The recessions can be treated by different surgical procedures. After a review of the etiologic factors and of the different type of wound healing, the authors describe and illustrate respectively the gingival graft for root coverage and the laterally positioned flap.