Pages 525-537, Language: English
This study evaluated candidate carriers for recombinant human bone morphogenetic protein-2 (rhBMP-2)-driven periodontal regeneration. Previous experiments indicated the ability of rhBMP-2 in a particulate delivery system to result in substantial regeneration of bone and periodontal attachment. In the present study, canine demineralized bone matrix (DBM), bovine deorganified crystalline bone matrix (Bio-Oss), an absorbable collagen sponge (ACS) of type I bovine collagen, poly(D,L-lactide-co-glycolide) microparticles (PLGA), and polylactic acid granules (Drilac) were tested for their ability to support rhBMP-2 (0.2 mg/mL implant volume)-driven periodontal regeneration. The implants were tested in routine critical size canine supra-alveolar periodontal defects with transgingival tooth positioning. Contralateral defects in six beagle dogs were semirandomly assigned to receive: DBM/rhB MP-2, DBM (no rhBMP-2), Bio-Oss/rhBMP-2, ACS/rhBMP-2, PLGA/rhBMP-2, or Drilac/rhBMP-2. Animals were sacrificed 8 weeks postsurgery, and block sections of the defects were processed for light microscopy. Substantial bone regeneration was observed in all defects implanted with rhBMP-2. Other measures of periodontal healing, including cementum regeneration and presence of ankylosis, were more variable between the implants. DBM and Bio-Oss performed well as carriers for rhBMP-2-driven periodontal regeneration, although other impediments to their clinical use exist. This study indicates that qualities of the carrier system, including its space-maintaining capacity, can affect the ability of rhBMP-2 to regenerate both alveolar bone and periodontal attachment.
Pages 539-545, Language: English
Subepithelial connective tissue grafts and guided tissue regeneration have been shown to be effective means to obtain root coverage. The purpose of this study is to compare statisticaly the results obtained with these techniques 1 year after the surgical procedures were performed. Thirty-six gingival recessions belonging to Class I and Class II of the Miller classification were treated: 18 cases with subepithelial connective tissue grafts (SCTG) and 18 cases with guided tissue regeneration (GTR). Each patinet was randomly assigned to a group. At baseline, the group treated with subepithelial connective tissue grafts presented a mean recession of 4.88 mm, whereas the group treated with guided tissue regeneration presented a mean recession of 5.88 mm (P = 0.82). After 1 year, the mean root coverage was 77.08% in the SCTG group and 80.88% in the GTR group. The difference was not statistically significant (P > .05). The mean root coverage was 3.83 mm for the SCTG group and 4.61 mm for the GTR group. The mean gain in probing attachment level was 3.05 mm for the SCTG group and 5.55 mm for the GTR group. The difference was statistically significant (P = .01). In conclusion, the mean root coverage obtained was similar for the two groups, whereas the clinical attachment gain was greater in the GTR group. Therefore, it appears that the GTR technique is preferable when severe mucogingival defects are present and gain of clinical attachment level is mandatory.
Pages 547-559, Language: English
A new surgical approach for interproximal regenerative procedures has been utilized in conjunction with bioresorbable barrier membranes in the treatment of deep intrabony defects. The purpose of this study was to test the effectiveness of the modified papilla preservation technique in obtaining and maintaining primary closure of the interdental space over bioresorbable membranes. Ten patients (10 sites) with optimal plaque control were treated according to the modified papilla rpeservation technique. Baseline probing attachment level and probing pocket depth were 10.1 ± 1.9 mm and 8.9 ± 2.4 mm, respectively. The intrabony component of the defects was 6.5 ± 1.7 mm. Polylactic acid barrier membranes were positioned just coronal to the interproximal bone crest. Primary closure over the membranes was obtained in 100% of the cases. In two cases only a slight dehiscence of the interproximal tissues was observed after 2 weeks. Healing was uneventful in all the treated sites. Probing attachment level gains of 4.5 ± 0.9 mm and a probing pocket depth reduction of 5.8 ± 2.3 mm were observed at 1 year. It can be concluded that the modified papilla preservation technique is a suitable alternative for interproximal regenerative procedures in conjunction with bioresorbable barrier membranes.
Pages 561-569, Language: English
Provisional restorations represent a key element in the reali zation of extensive esthetic rehabilitations. In particular, they provide indispensible diagnostic information, contribute significinatly to adjacent soft tissue conditioning, and ensure the patient's comfort during the intermediate phase of treatment. The treatment outcome strongly depends on the treatment approach chosen. This article describes a treatment rationale comprising the use of a diagnostic template. This type of work stratgey, documented with clinical cases, integrates diagnostic waxups and indirect provisional restorations using simplified and efficient fabrication techniques
Pages 571-581, Language: English
Three cases are presented demonstrating that soft tissue augmentation procedures can be accomplished on previously restored root surfaces. Diagnostic techniques to help determine ideal tooth length are discussed, and clinical examp les of how to surgically manage the previously restored root surfaces are presented.
Pages 583-593, Language: English
The purpose of this study was to evaluate soft tissue healing and osseointegration of dental implants after the use of vestibular incision or crestal incision flap designs during placement of the dental implant fixture. A split-mouth design was used in 10 patients. The vestibular flap technique was used for half the implant fixtures and the crestal incision for the other half. Postsurgical healing was monitored for 30 days, and osseointegration at second-stage surgery was evaluated. The short-term results suggest that the use of either the vestibular incision or the crestal incision technique did not affect overall clinical healing or osseointegration.
Pages 595-601, Language: English
The purpose of this study was to compare the characteristics of three different restorative materials for the treatment of subgingival root lesions. Eighteen recently extracted teeth were used to test the depth of cure and the surface characteristics of these products. Although none of the materials tested exhibited all of the author's ideal characteristics for a subgingival restorations, one restorative material displayed the most favorable result.