Abstract: Objective To explore wound healing status after the guided bone regenerationsurgery using bone collagen and to compare changes of alveolar bone density before the surgery,1 month and 4 months after the surgery.Methods 21 teeth from 15 chronic periodontitis patients(6 males，9 females) with bone defects requiring prevention of alveolar bone absorption were selected in this research.Physical examination was used to examine the healing status after teeth extraction.The grey values of alveolar crests and dental crowns were measured with PLANMECA digital panorama tomograph.Oneway analysis of variance was used to compare the preoperative and postoperative changes of the grey values.Results The grey values of the alveolar crests and dental crowns before the surgery,1 and 4 months after the surgery were 0.35±0.06,0.43±0.03,and 0.54±0.04,respectively.There were statistical differences between groups(P＜0.01).Conclusions Guided bone regeneration with bone collagen is a simple and practical method for bone augmentation,which can significantly improve the alveolar bone condition.Besides,it can provide favorable conditions for stage IIpreprosthetic treatment and aesthetic restorations.

Key words: digital panoramic tomograph, guided bone regeneration surgery, bone density