Abstract: PURPOSE: To evaluate the effect of concentrated growth factor (CGF) membrane and Haiao oral repair membrane on the preservation of extraction sites in the posterior area of teeth. METHODS: A total of 96 patients requiring site preservation after posterior tooth extraction from January 2020 to December 2022 were selected and divided into groups A and B by random number table method, with 48 cases in each group. After tooth extraction, Bio-Oss bone powder was used to cover tooth extraction wound in group A with CGF membrane, and in group B with Haiao oral repair membrane. The healing of the operative area, the changes of vertical height and horizontal width of alveolar bone, visual analog scoring (VAS) of pain, the changes of buccal and palatal tissue thickness and the rate of bone replantation were compared between the two groups. RESULTS: One week after operation, the tooth extraction wound in group A healed well, while 2 cases in group B healed poorly, but there was no significant difference between the two groups(P>0.05). Before surgery, there was no significant difference in vertical height and horizontal width of alveolar bone between the two groups(P>0.05); at 6 months after operation, the vertical height of alveolar bone was significantly increased and the horizontal width was significantly decreased(P<0.05), but there was no significant difference between the two groups(P>0.05).The VAS score of pain 1 week after surgery in 2 groups was lower than that 3 days and 24 hours after surgery, and the VAS score of pain in group A was lower, and the interaction between groups, and time points were significantly different(P<0.05).There was no significant difference in the thickness of buccal and palatal tissues between the two groups before and 6 months after surgery(P>0.05); at 6 months after surgery, the tissue thickness of the palatal side in group B was significantly lower than before surgery(P<0.05). Six months after surgery, the bone replantation rates in group A and group B were 4.17% and 6.25%, respectively, with no significant difference between the two groups(P>0.05). CONCLUSIONS: Both CGF membrane and Haiao oral repair membrane have good efficacy in the preservation of tooth extraction sites in the posterior region, which can effectively delay alveolar bone mass absorption, and CGF has a better effect in reducing short-term postoperative pain in patients.

Key words: Preservation of tooth extraction site, Concentrated growth factor, Haiao oral repair membrane, Alveolar bone