| In order to ensure an adequate space where new bone can be formed in guided bone regeneration (GBR), most surgeons fill bone defects with biomaterials. In this work we evaluated new bone regeneration in 10 patients using only a blood clot protected with titanium grids and non-resorbable membranes, without any filling material. A manual measurement of the size of the bone defect, using a plastic probe, was performed at 2 surgical steps. After 5 months of treatment, a biopsy was taken from each patient, fixed and embedded in PMMA, examined microradiographically and morphologically to evaluate the newly-formed bone. Our results showed a good repair of the defects by bone regeneration (about 85% overall), high mineral density of new bone around the implants after 5 months, and steady state deposition processes. These results in GBR, without filling material, appear very promising for implantology and reconstructive odontostomatology practice. ( info) |
2/447. guided tissue regeneration in the management of severe periodontal-endodontic lesions. diagnosis of combined periodontal-endodontic lesions can prove difficult and frustrating. They are often characterised by extensive loss of periodontal attachment and alveolar bone, and their successful management depends on careful clinical evaluation, accurate diagnosis, and a structured approach to treatment planning for both the periodontic and endodontic components. Recent advances in regenerative periodontics have led to improved management of periodontal-endodontic lesions. This paper reviews the management of such lesions in light of these recent advances and illustrates this through reports of two patients who had severe periodontal involvement. ( info) |
3/447. Tomodensitometric and histologic evaluation of the combined use of a collagen membrane and a hydroxyapatite spacer for guided bone regeneration: a clinical report. In this report, the problems of insufficient bone and soft tissue after extraction of maxillary incisors were addressed concurrently prior to endosseous implant placement, by combining the use of a diphenylphosphorylazide-cross-linked Type I collagen membrane and a resorbable space-making biomaterial composed of 200-micron porous hydroxyapatite granules blended in Type I collagen and chondroitin-4-sulfate. Upon flap reflection 8 months postsurgery, the horizontal deficiencies were almost completely resolved, membranes completely resorbed and the defects filled with hard, bonelike tissue, with a few superficial hydroxyapatite granules. Histologic evaluation of the bone biopsies obtained at the implantation sites revealed dense, well-reconstructed alveolar bone with a few traces of hydroxyapatite granules that had been completely resorbed. Tomodensitometric evaluation indicated that bone regeneration ranged from 14% to 58%, with an average bone gain of 29.77%. Four nonsubmerged ITI titanium implants placed in the augmented bone have been in function for more than 5 years, with no clinical or radiographic signs of hard or soft tissue breakdown. Bacterial sampling at dental sites with periodontitis 1 month prior to periodontal therapy and at implant sites for up to 30 months demonstrated rapid colonization of implant surfaces by periodontopathogens without causing any detrimental effect to implant integration. ( info) |
4/447. The profile prosthesis: an aesthetic fixed implant-supported restoration for the resorbed maxilla. This article discusses a method for the predictable fabrication of fixed detachable maxillary reconstructions that abut and precisely follow the gingival contours--regardless of implant angulation or position. The technique reorders the traditional implant protocol and delays abutment selection until the definitive tooth position has been established. In this manner, final abutment selection and framework design become a single, integrated process that results in improved aesthetics, reduced angulation difficulties, and elimination of the phonetic concerns traditionally associated with fixed maxillary prostheses. ( info) |
5/447. Tissue necrosis after subgingival irrigation with fluoride solution. Irrigation of periodontal pockets with fluoride solution after scaling and root planing is occasionally recommended to inhibit the growth of pathogenic bacteria in the periodontal pocket. At the same time, irrigation enables mechanical removal of loosely adhering plaque and debris. Due to its toxicity, fluoride solution deposited in the periodontium may lead to tissue damage. We report in this paper, a case of extensive periodontal tissue necrosis and permanent loss of alveolar bone after irrigation of periodontal pockets with stannous fluoride solution. The literature on the toxic effects of fluoride on the local tissues is briefly reviewed and arguments for a re-evaluation of the use of stannous fluoride for pocket irrigation are provided. ( info) |
| There continues to be increased expansion of implant services corresponding to the public's increased awareness of implant-borne prostheses as a regular part of treatment planning. This rise in public awareness as practitioners expand their skills will lead to the consideration of an implant option for growing groups of patients whose medical histories may have previously contraindicated implantology. This presentation is one such case. ( info) |
7/447. Spacemaking metal structures for nonresorbable membranes in guided bone regeneration around implants. Two case reports. This article presents a surgical technique to promote bone regeneration and enlargement of localized alveolar ridge defects in the mandible. The purpose of this study was to investigate the use of spacemaking gold frames used in combination with expanded polytetrafluoroethylene Gore-Tex augmentation membranes (WL Gore) on two patients to create and maintain adequate space for the regeneration of bone. The membrane was sutured under the frame and the assembly was bent and adapted over the residual bony defect to create a dome and prevent the expanded polytetrafluoroethylene barrier membranes from collapsing into the defects. The framed membranes have also been positioned over dehisced implants. After a healing period of 12 months, a second-stage surgery procedure was performed to remove the gold frames and expanded polytetrafluoroethylene membranes and to connect the healing abutments. The gain of bone dimension was assessed by standardized measurements. On both patients the spaces created by the framed membranes were completely filled with newly regenerated bone. Biopsies from the treated sites revealed new bone formation. ( info) |
8/447. Periodontal and peri-implant bone regeneration: clinical and histologic observations. The principle of guided tissue regeneration by barrier membranes to restore lost periodontal tissue around natural teeth has also been used around osseointegrated implants in an attempt to restore alveolar ridge defects. While most periodontal procedures in the literature describe root coverage by mucogingival surgery, which achieves healing through soft tissue attachment, regeneration of denuded root surfaces is performed by guided tissue regeneration using expanded polytetrafluoroethylene barrier membranes and demineralized freeze-dried bone allografts as inductive/conductive materials. In this study the technique is applied in two partially exposed cylindrical hydroxyapatite-coated implants in extraction sites in one patient. Surgical reentry in both sites is presented, with histologic examination revealing new bone formation on the exposed root surface and the hydroxyapatite-coated implants. ( info) |
9/447. guided tissue regeneration procedure applied to the treatment of endodontic-periodontal disease: analysis of a case. The clinical condition of a patient with chronic adult-type periodontal disease, as well as gingival recession reaching the tooth apex on a mandibular lateral incisor, is discussed. Because the use of conventional techniques would have resulted in tooth loss, the guided tissue regeneration procedure was applied, with successful results. ( info) |
10/447. bone regeneration around an osseointegrated implant. A simultaneous approach in a fenestrated defect: a case report. The use of a barrier membrane, with or without osseous allograft, has been shown to establish regeneration of osseous tissue around dental implants. Following three episodes of persistent symptomatic failed apicoectomy and subsequent tooth extraction, an osseointegrated implant was placed in a wide fenestrated defect. Demineralized freeze-dried bone allograft was covered by an occlusive expanded polytetrafluorethylene membrane. The reentry procedure revealed complete bone fill that followed the texture of the augmentation material beyond the previous buccal bony envelope. ( info) |