title: The effect of platelet-rich plasma on clinical outcomes of the surgical treatment of periodontal intrabony defects: A systematic review and meta-analysis.
abstract: BACKGROUND
  Studies investigating the use of platelet-rich plasma (PRP) in the treatment of intrabony defects have yielded mixed results. The aim of our study was to evaluate the efficacy of PRP by comparing clinical attachment level (CAL) and pocket depth (PD) for patients who received PRP as an adjunct to periodontal intrabony defect therapy with those for patients who did not. We also analyzed the influence of guided tissue regeneration (GTR) and different study designs (parallel and split-mouth studies) on the clinical outcomes of intrabony defects.
  
  
  METHODS
  We performed a systematic review of articles published in any language up to June 7, 2015 by searching PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials. We included only randomized controlled clinical trials (RCTs) that compared clinical outcomes between patients who received PRP as an adjunct to periodontal intrabony defect therapy and patients who did not. We combined data from randomized trials to assess clinical outcomes using a random-effects model.
  
  
  RESULTS
  Of the 307 abstracts that were initially identified, 12 RCTs related to the treatment of periodontal intrabony defects were included in the final analysis. Clinically and significantly greater CAL gains and PD reductions were observed in subjects who received PRP as an adjunct to periodontal intrabony defect therapy than in subjects who did not (CAL: WMD 0.76 mm, 95 % CI = 0.34 to 1.18 mm, P = 0.0004; PD: WMD 0.53 mm, 95 % CI = 0.21 to 0.85 mm, P = 0.001). Subgroup meta-analyses of patients who underwent GTR demonstrated that this approach did not significantly affect treatment outcomes (CAL: WMD 0.08 mm, 95 % CI = -0.30 to 0.46 mm, P = 0.67), as indicated by a comparison with patients who did not undergo GTR (CAL: WMD 1.22 mm, 95 % CI = 0.88 to 1.57 mm, P < 0.00001). Univariate meta-regression analyses revealed that the use of GTR explained the heterogeneity among the included studies (P < 0.05).
  
  
  CONCLUSIONS
  Within its limitations, this review suggests that PRP may be beneficial as an adjunct to graft materials for the treatment of periodontal intrabony defects, except in cases involving the use of GTR.
authors.affiliation: The Oral Medicine Clinical Center, The First Affiliated Hospital of Xinjiang Medical University, No. 137 South Liyushan Road, Urumqi, 830054, People's Republic of China.
authors.forename: Xinshan
authors.initials: X
authors.lastname: Hou
authors.affiliation: The Oral Medicine Clinical Center, The First Affiliated Hospital of Xinjiang Medical University, No. 137 South Liyushan Road, Urumqi, 830054, People's Republic of China.
authors.forename: Jingwen
authors.initials: J
authors.lastname: Yuan
authors.affiliation: The Oral Medicine Clinical Center, The First Affiliated Hospital of Xinjiang Medical University, No. 137 South Liyushan Road, Urumqi, 830054, People's Republic of China.
authors.forename: Absijiang
authors.initials: A
authors.lastname: Aisaiti
authors.affiliation: The Oral Medicine Clinical Center, The First Affiliated Hospital of Xinjiang Medical University, No. 137 South Liyushan Road, Urumqi, 830054, People's Republic of China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Stomatology Disease Institute of Xinjiang Uyghur Autonomous Region, No. 137 South Liyushan Road, Urumqi, 830054, People's Republic of China. merryljin@sina.com.
authors.forename: Jin
authors.initials: J
authors.lastname: Zhao
mesh_terms: D016301:Alveolar Bone Loss / Q000628:therapy*; D005500:Follow-Up Studies; D016557:Guided Tissue Regeneration, Periodontal; D006801:Humans; D017622:Periodontal Attachment Loss; D053657:Platelet-Rich Plasma; D016896:Treatment Outcome
keywords: Meta-analysis; Periodontal disease; Platelet-rich plasma; Randomized controlled trial