A comparative study of the effects of advanced platelet-rich fibrin and resorbable collagen membrane in the treatment of gingival recession: a split-mouth, randomized clinical trial.

Aim: This study aimed to assess the effectiveness of advanced platelet-rich fibrin (A-PRF) combined with the pinhole surgical technique (PST) for enhancing root coverage (RC) in individuals with Miller class I or II gingival recessions (GR). Additionally, it compared the clinical effect of A-PRF and resorbable collagen membrane (RCM).

Materials and methods: A total of 18 patients, encompassing 36 treatment sides of 18 Miller class I or II, were randomly assigned to the PST + A-PRF side (18 sides) and the PST + RCM side (18 sides). Clinical assessments of various parameters, including plaque index (PI), clinical attachment level (CAL), keratinized tissue width (KTW), recession depth (RD), recession width (RW), and gingival thickness (GT) were conducted at baseline and three months after the surgical procedure. A numeric rating scale (NRS) was also evaluated during the 1st, 2nd, 3rd and 4th days. This study was formally recorded under the TCTR identification number TCTR20230613005 in the Thai Clinical Trials Register-Medical Research Foundation of Thailand (MRF) on 13/06/2023. Furthermore, it was ethically approved by Sana'a University's Ethical Committee for Medical Research.

Results: When comparing the values of 3 months follow-up with the baseline values, intra-side comparison of the PST + A-PRF group showed significant improvements in PI (P = 0.02), CAL (P = 0.01), and RD (P = 0.04), and GT values (P < 0.01). The improvements in the PST + A-PRF group were through the reduction of baseline values of PI, CAL, and RD; the mean reductions in PI, CAL, and RD were 0.44 ± 0.71, 0.33 ± 0.45, and 0.22 ± 0.43 respectively, and a significant increase in GT value (0.44 ± 0.24). While there was an insignificant increase in KTW value with no change in RW values (4.50 ± 0.71, P = 1). In contrast, intra- side comparison of PST + RCM side showed only a significant reduction in PI value (0.44 ± 0.71, P = 0.02) and a significant increase in GT value (0.42 ± 0.26, P = < 0.01). Meanwhile, there were insignificant improvements in CAL (2.89 ± 0.95), KTW (3.97 ± 0.74), and RD (1.94 ± 0.87) values. Regarding inter-side comparison, there were no statistically significant among all variables (p > 0.05). The pain scores of the numeric rating scale were significantly lower on the PST + A-PRF sides compared with the PST + RCM sides, especially on the 1st, 2nd, and 3rd days (P < 0.001).

Conclusion: Both A-PRF and RCM showed not wholly satisfactory outcomes in gingival recession treatment. Interestingly, the combination of PST with A-PRF has proven more effective than combining PST with RCM. Additionally, the localized application of A-PRF has been shown to reduce post-operative pain following the pinhole surgical technique.