Histological evaluation of oral implants inserted with different surgical techniques into the trabecular bone of goats.

Contains fulltext : 53500.pdf (publisher's version ) (Closed access)OBJECTIVE: The aim of this study was to investigate the influence of implant surface topography and surgical technique on bone response. MATERIAL AND METHODS: For the experiment, 48 screw-designed implants were used with two different surface finishes, i.e. machined and 'blasted, etched'. The implants were inserted into the left and right medial femoral condyle of eight goats using three different surgical approaches: press-fit (implant diameter=implant bed diamete(r), undersized (implant bed diameter<implant diameter) and osteotome. Each femoral condyle received three implants. After an implantation period of 12 weeks, the implants were retrieved and prepared for histological and histomorphometrical evaluation (bone contact and bone mass). RESULTS: Light microscopy revealed that in general, the bone response to all implants was very similar. On the other hand, histomorphometry suggested that the bone-to-implant contact for the 'blasted, etched' implants inserted by an undersized technique was higher compared with machined implants and the other surgical approaches, but the observed differences were not significant. Bone mass measurements did not reveal the occurrence of clear differences between groups and surgical approaches. CONCLUSION: Supported by our findings, we conclude that implants provided with a 'blasted, etched' surface and installed in trabecular bone using an undersized preparation technique appear to support an enhanced bone-implant contact. The use of an osteotome technique did not lead to improved results

Effect of absorbable membranes on sandwich bone augmentation

Objectives : This study was conducted to evaluate the effect of barrier membranes on sandwich bone augmentation (SBA) for the treatment of implant dehiscence defects. Material and methods : Twenty-six implant-associated buccal dehiscence defects in 22 patients were treated according to the SBA concept – mineralized human cancellous allograft (inner layer), mineralized human cortical allograft (outer layer) and coverage with barrier membrane. The defects were randomly assigned to the bovine collagen membrane (BME) group; acellular dermal matrix (ADM) group; and no membrane group. Measurements at baseline and 6 months re-entry included defect height (DH: from smooth–rough junction to the most apical part of the defect), defect width (DW: at the widest part of the defect), and horizontal defect depth (HDD: at three locations – smooth–rough junction, middle, and most apical portion of the defect). All measurements were taken from a reference stent. Statistical analyses were performed for comparison of intra- and inter-group comparisons. Results : All implants placed were successfully osseointegrated. DH at baseline for three groups were not significantly different ( P =0.858). Mean % DH reductions for ADM, BME, and control groups at 6 months were 73.9±17.6%, 68.1±30.1%, and 63.6±23.9%, respectively, with no significant difference among the groups ( P =0.686). Mean horizontal bone gain, however, was significantly greater for membrane groups (1.7 mm for ADM, 1.6 mm for BME) compared with control group (1 mm) ( P =0.044). Implant exposure resulted in significant reduction in total height gain (79.1±14.3% vs. 57±23.5%, P =0.021). Conclusions : Within the limit of this study, it is concluded that SBA technique achieved predictable clinical outcomes. The addition of absorbable membranes enhanced bone gain in thickness compared with membrane-treated sites. To cite this article: Park S-H, Lee K-w, Oh T-J, Misch CE, Shotwell J, Wang H-L. Effect of absorbable membranes on sandwich bone augmentation. Clin. Oral Impl. Res . 19 , 2008; 32–41. doi: 10.1111/j.1600-0501.2007.01408.xPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74133/1/j.1600-0501.2007.01408.x.pd