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

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.

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).

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)∼(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.

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.