To evaluate the effect of platelet-rich fibrin (PRF) and Haiao collagen membrane on the site preservation after tooth extraction with guided bone regeneration (GBR) .

A total of 84 cases received site preservation after tooth extraction with GBR from June 2016 to September 2018, were selected and grouped with the random number table method. Both the test and control group enrolled 42 cases for each. A bone substitute (Bio-Oss) was filled in the socket after minimally invasive tooth extraction. The test and control groups were covered with PRF and Haiao collagen membrane, respectively. Then, the wound healing rate, alveolar bone width and height, and aesthetic score of two groups were recorded and compared with the independent sample t test.

The wound healing rate after two weeks in the test group was (77.1 ± 6.14) %, compared with the control group of (65.8 ± 3.7) %, which was significantly higher (t= 10.188, P<0.001) . The wound healing rate after four weeks in the test group was (98.8 ± 12.5) %, compared with the control group of (78.7 ± 7.1) %, which was significantly higher (t = 9.084, P<0.001) . There was no significant difference in alveolar bone height between the two groups before extraction (t = 0.022, P = 0.982) . After extraction for one month, the alveolar bone height in the test group was (15.1 ± 1.9) mm. Compared with the control group of (14.2 ± 1.8) mm, it was significantly higher (t = 2.091, P=0.039) . After extraction for three months, the alveolar bone height in the test group was (14.2 ± 1.8) mm. Compared with the control group of (14.0 ± 1.3) mm, the test group was significantly higher (t = 2.608, P = 0.010) . There was no significant difference in alveolar bone width between the two groups before extraction (t = 0.062, P = 0.950) . After extraction for one month, the alveolar bone width in the test group was (7.1 ± 0.6) mm. Compared with the control group of (6.8 ± 0.7) mm, it was significantly wider (t = 2.392, P = 0.019) . After extraction for three months, the alveolar bone width in the test group was (6.9 ± 0.4) mm. Compared with the control group of (6.4 ± 0.5) mm, it was significantly wider (t = 5.748, P<0.001) . There was no significant difference in the PES scores between the two groups after immediate restoration (t = 0.142, P = 0.887) . After three months, the PES score in the test group was (12.4 ± 4.0) , and the control group was (10.5 ± 2.0) . The former was significantly higher (t = 2.644, P = 0.009) . After six months, the PES score in the test group was (12.9 ± 4.18) . Compared with the control group of (12.5 ± 3.7) , the test group was significantly higher (t = 0.617, P = 0.538) . There was no significant difference in the WES scores between two groups after immediate restoration (t = 0.261, P = 0.794) . After three months, the WES score in the test and control groups were (9.1 ± 1.0) and (8.1 ± 0.7) , respectively, indicating the former was significantly higher (t = 5.176, P<0.001) . After six months, there was no significant difference in the WES score between the two groups (t = 1.318, P = 0.191) .

The effect of PRF on the site preservation after tooth extraction with GBR was better than that of Haiao membrane, which indicated that PRF can improve the wound healing rate, maintain the width and height of alveolar bone, and achieve satisfactory short-term aesthetic effect.