Clinical effectiveness of a topical subgingival application 
of injectable platelet-rich fibrin as adjunctive therapy 
to scaling and root planing: a double-blind, split-mouth, randomized, prospective, comparative controlled trial

Objective: The purpose of this randomized, controlled, split-mouth clinical trial was to clarify the clinical efficacy of using injectable platelet-rich fibrin (i-PRF) as an adjunctive subgingival irrigation to scaling and root planing (SRP) in the treatment of periodontitis.
Method and materials: The study was conducted in 15 patients suffering from stage II to III with grade B to C periodontitis with bilateral periodontal pockets (≥ 5 mm) on a minimum of two teeth without degree II or III of furcation involvement or tooth mobility. The evaluated clinical parameters were: Plaque Index (PI), bleeding on probing (BOP), probing pocket depth (PPD), clinical attachment level (CAL), and gingival recession at baseline and after 3 months. After full-mouth supra- and subgingival SRP, the sites were randomly divided into test sites receiving the subgingival application of i-PRF and controls treated with saline. The Wilcoxon test and Mann-Whitney U test were used for intra- and inter-group comparisons, respectively.
Results: In total, 726 sites were treated (388 test group and 338 control group) with no uneventful healing effects. Statistically significant decreases in PI (P = .001), BOP (P = .001 for both groups), PPD (P = .001 and P = .000 for test and control groups, respectively), CAL (P = .015 and P = .001 for test and control groups, respectively) between pretreatment and 3 months posttreatment were noted in both test and control groups. For inter-group comparisons, there was no statistically significant difference in all clinical indices (P > .05).
Conclusion: In this study, both groups were clinically effective as nonsurgical periodontal treatments, without any clinical benefits of using i-PRF.