Platelet-rich plasma for periodontal regeneration in the treatment of intrabony defects: a meta-analysis on prospective clinical trials

Objective. The aim of this systematic review and meta-analysis was to assess the influence of platelet-rich plasma (PRP) on the regeneration of periodontal intrabony defects by means of evaluating clinical and radiographic outcomes in prospective human clinical trials. Background. PRP is a high concentration of platelets suspended in a small volume of plasma and has been used for periodontal tissue regeneration. However, although it has been broadly studied, there is much controversy on its efficacy when used to treat infrabony periodontal defects. Methods. An electronic literature search was conducted by two reviewers (AR and AM) in several databases up to February 2014. The PICO question was: Does PRP have a higher or similar efficacy of regenerating periodontal intrabony defects compared with other conventional periodontal regeneration treatments (e.g., bone grafts, barrier membranes)? Articles were included in this systematic review if they were prospective clinical trials with 10 or more human patients, reporting the radiographic and/or clinical outcomes PRP for regeneration intrabony periodontal defects. Random effects meta-analyses of the selected studies were applied to avoid any bias being caused by methodologic differences among studies. Results. Twenty-two papers were obtained and reviewed. Of these, 21 articles fulfilled the inclusion criteria and subsequently were qualitatively analyzed. Eighteen of these could be meta-analyzed. Fourteen articles were included for evaluating of probing pocket depth (PPD). The weighted mean difference (WMD) was 0.55 mm, with a 95% CI = -0.09 to 1.20 mm (P = .09). For bone level (BL), 2 articles measured BL in millimeters, and the other two articles measured BL in percentage. The WMD was 0.76 mm (95% CI = 0.21-1.31 mm; P = .007) and 47.41% (95% CI = 32.48%-62.33%; P <.0001), respectively. For attachment level (AL) changes, 12 articles were included. The WMD was 0.58 mm, with a 95% CI = 0.24 to 0.91 mm (P = .0008). Sixteen articles were included for evaluation of marginal gingival level (MGL). The WMD = 0.10 mm, with a 95% CI = -0.19 to -0.01 (P = .03). Conclusions. High heterogeneity among studies made it difficult to draw clear conclusions. Nonetheless, within the limitations of this review, PRP might offer some beneficial effects on clinical and radiographic outcomes for regeneration of periodontal intrabony defects.