光固化壳聚糖-明胶复合三维支架对维持拔牙后牙槽嵴高度和宽度的影响

目的 研究新型光固化壳聚糖 明胶复合三维支架在拔牙后动物模型位点保存中的应用。方法 采用二甲基亚砜/光固联技术合成新型光固化壳聚糖 明胶复合三维支架，并采用乳液冷冻干燥法，制备了支架/rhBMP 2复合体。取8只Beagle犬，取下颌拔牙窝为实验位点，左右两侧共计64个位点，随机分为空白对照组（Control组）、空白支架组（S0组）、支架+肝素组（SH组）、支架+BMP2组（SB组），并植入相应支架。术后90 d处死动物，采集术前、术后牙槽嵴髙度及宽度数据，并取下牙槽窝加上近远中两个牙位的牙槽骨，行显微 CT扫描和组织学检查。结果 在牙槽骨宽度、高度丧失上，S0、SH、SB组均小于Control组（P<0.05），组间比较中，SB组均小于S0、SH组（P<0.05）；显微CT 三维重建后显示S0、SH、SB组较好的保留了原牙槽嵴宽度和外形，Control组牙槽嵴则明显变窄，并出现局部吸收；组织学上，SB组基本未见吸收，形成了成熟的骨小梁,骨质钙化程度高于Control组、S0组、SH组。结论 新型三维支架在动物模型上可以实现良好的成骨效果，较好地维持了拔牙后牙槽嵴的高度和宽度。

Effect of photocured chitosan-gelatin 3D scaffold on the height and width of alveolar ridge after tooth extraction

Objective To analyze the application of the novel chitosan gelatin 3D scaffold in socket preservation therapy. Methods The novel chitosan gelatin 3D scaffold was composed by dimethyl sulfoxide (DMSO)/UV crosslink. Then the scaffold was compounded with rhBMP 2. Eight beagle dogs, sixteen sockets after teeth extraction in the left and right mandibles were selected. The sockets were divide into control group, empty scaffold group (S0 group), scaffold+ heparin group (SH group), scaffold+BMP2 group (SB group) by random. The scaffolds were implanted in each group following the group division. The animals were put into death 90 days after the surgery. The heights and widths of each socket’s alveolar bone were measured. Then the socket’s alveolar bones were analyzed by micro CT and histology. Results The alveolar bone width and height loss in S0, SH, SB groups were less than those of control group (P<0.05). By comparison between groups, SB group and SH group were less than S0 (P<0.05). Micro CT 3D reconstruction showed that S0 group, SH group and SB group were better in retaining the original alveolar ridge width and shape. The control group obviously had narrow alveolar ridge, and there were some local absorptions; histologically, in SB group no bone was absorbed, a mature bone trabeculae formed and bone calcification degree was higher than other groups. Conclusion The new three dimensional scaffold can achieve good bone formation in animal models, which can maintain the height and width of alveolar ridge after tooth extraction.