[Guided bone regeneration at a dehiscence-type defect using chitosan/collagen membranes in dogs].

OBJECTIVE: To compare a developed absorbable chitosan/collagen membrane (CCM) with a standard biodegradable collagen membrane for the treatment of implant dehiscence-type defect in dog model. METHODS: The right four mandibular premolars and the first molar were extracted in each of 10 beagle dogs.Four months later, acute buccal dehiscence-type defects were surgically created following implant site preparation in each dog. Using self-control, defects were randomly assigned to four different groups: CCM-1 (with the ratio of chitosan and collagen of 40: 1), CCM-2(with the ratio of chitosan and collagen of 20: 1), Bio-Gide collagen membrane (BG collagen), control. The animals were sacrificed after 4 (3 animals), 8 (3 animals) and 12 (4 animals) weeks of healing interval for histological observation and histomorphometrical analysis including defect length (DL), new bone height (NBH), bone-to-implant contact (BIC) and area of new bone fill (BA). RESULTS: Newly formed bone was observed in all the groups and became mature with time. At 8 weeks, increased mean NBH and BIC values were obtained for all the groups, the mean NBH values of the CCM-1, CCM-2 and BG groups [( 1.1 0 +/- 0.11) approximately (1.48 +/- 0.07) mm]were significantly higher than that of the control [(0.74 +/- 0.12) mm] (P < 0.05). At 12 weeks, the membranes treated groups obtained more mean NBH,BIC and BA values compared with the control. The CCM-1 groups showed the highest mean NBH value [(1.91 +/- 0.25) mm], which was significantly higher than the control [(1.20 +/- 0.34) mm](P < 0.05).However, no statistically significant differences in BIC and BA were found between membrane groups and control and among the membranes treated groups. CONCLUSIONS: The results of this study demonstrated that the developed CCM can enhance bone regeneration and obtaine similar amounts of newly formed bone compared with defects regenerated with a standard collagen membrane.