In Vivo Evaluation of Chitosan/γPGA Hydrogel Dressing in Post-Extraction Sockets

Objectives: The healing of extraction wound takes 4 months and 4 mm of bone height were lost in average. This makes proceeding treatment such as implant or denture difficult. Chitosan has antiseptic, biocompatible, and degradable properties; besides, γPGA was reacted with chitosan to form hydrogel at controlled pH. The purpose of this study was to propose a novel chitosan/γPGA Hydrogel for extraction socket dressing and evaluate the effect on healing. Methods: Fifty female Wistar rats were used. Sixty-four extraction sockets were randomly selected and divided into 4 groups: no dressing material insertion, Spongostan®, chitosan-sponge, chitosan/γPGA Hydrogel. The rats were sacrificed at the time interval of 1, 2, 4, 6 weeks for further radiographic and histological evaluations. The results were analyzed statistically by chi-square test and a significance level of 0.05. Results: At 2nd week, radiopaque images were only noted in Chitosan/γPGA Hydrogel group. Histological findings showed Chitosan/γPGA Hydrogel could completely degrade in 4 weeks. It promoted more mature bone formation and rapid wound healing of extraction sockets with significant difference. Six weeks after implantation, extraction sockets were almost filled with new bone in Chitosan/γPGA Hydrogel group which showed significant difference to other groups(p<0.05). Conclusion: Chitosan/γPGA Hydrogel is a novel biomaterial with potential for promoting healing of extraction socket and maintaining the bone height.