Objective: To study the microstructure of e-polytetra fluoroethylene (e-PTFE) membrane and chitin membrane and to observe the growth of osteoblasts on the membrane. Methods: Light microscope and scanning electronic microscope were used to study the microstructure of e-PTFE membrane and chitin membrane. Cell culture methods and cell counting were used to observe the growth of osteoblasts on the two kinds of membrane. Results: The chitin membrane showed a compact structure without any pore in it. There were many shallow dents with the diameter of 5-8 ?m on it's surface. However, in e-PTFE membrane many tiny lined cracks (1-5 ?m in width and 5-15 ?m in length) in elliptic structure were observed. The adhesion and proliferation of osteoblasts on the two kinds of membranes were both well. ALP measurement showed that there were no significant difference between each of the two membrane groups and the control. Conclusions: Both membranes have no negative effects on the growth of osteoblasts. Both membranes are biocompatibile and their microstructure is appropriate for guided bone regeneration materials.

OBJECTIVETo 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.

METHODSThe 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).

RESULTSNewly 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.

CONCLUSIONSThe 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.

Animals ; Bone Regeneration ; Chitosan ; Collagen ; Dental Implantation, Endosseous ; Dogs ; Membranes, Artificial ; Surgical Wound Dehiscence ; Tooth Extraction ; Wound Healing