Martande 2016.

Methods	Trial design: randomised, parallel trial Location: Department of Periodontics, Government Dental College and Research Institute, Bangalore, India Number of centres: 1 Recruitment period: March 2013 to February 2014 Source of funding: not stated Ethical approval: Institutional Ethical Committee and Review Board of the Government Dental College and Research Institute, Bangalore, India Number of surgeons: 1
Participants	Inclusion criteria: patients with moderate‐to‐severe chronic periodontitis, based on the 1999 consensus classification of periodontal diseases; and presence of a 3‐walled infrabony defect ≥ 3 mm deep in which depth was measured radiographically from the alveolar crest to the base of defect on an intraoral periapical radiograph (IOPA) and the architecture of the 3‐walled infrabony defect confirmed upon surgical exposure of the defect Exclusion criteria: patients with aggressive periodontitis; patients with systemic diseases affecting periodontal condition; those who had received periodontal therapy during the previous 6 months and/or are taking antibiotics for any chronic inflammatory conditions; smokers; pregnant and/or lactating females. Individuals with unacceptable oral hygiene (PI > 1.5) after re‐evaluation of phase I therapy, and teeth with questionable to poor prognosis including: furcation defects; gingival recessions; carious teeth requiring extensive restorations; and non‐vital teeth were also excluded. In addition, 1‐walled and combined 1‐ and 2‐walled defects confirmed upon surgical exposure were also excluded from the study Age at baseline: 30 to 50 years; mean age = 37.6 years Gender: F 48/M 48 (for all 3 groups) Smokers: excluded Teeth treated: 42 sites were from maxillary and mandibular single‐rooted teeth, and the remaining 48 sites were from maxillary and mandibular multirooted teeth Number randomised (participants/teeth): 64/64 (96/96 for all 3 groups) Number evaluated (participants/teeth): 60/60 (90/90 for all 3 groups)
Interventions	Comparison: OFD + PRF versus OFD alone Test group: OFD + PRF (n = 30) Control group: OFD alone (n = 30) Surgical technique: full thickness mucoperiosteal flap with PRF in test site and full thickness mucoperiosteal flap alone in control site Follow‐up duration: 9 months
Outcomes	Clinical: PI, modified sulcus bleeding index, PD, relative attachment level, gingival margin level Radiographic: radiographic bone filling Other: none
Notes	Sample size calculation: yes Radiographs were standardized using customized bite blocks and parallel angle technique and scanned with a scanner of 6400 dots per inch Comparability at baseline: yes, assessed Complications reported: no complications Dropouts: reported, 4 dropouts (6 for all 3 groups, 2 for each group) 3rd group data (OFD + PRF + 1.2% atorvastatin gel) not included in this review
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Selected sites were divided randomly (computer‐generated tables) into control and test groups (PRF or PRF + 1.2% ATV [atorvastatin])" Comment: random sequence generation likely to have been done properly
Allocation concealment (selection bias)	Unclear risk	Quote: "Patients were masked regarding their allocation to specific group and treatment" Comment: insufficient information is provided for the allocation concealment method
Blinding of participants and personnel (performance bias) All outcomes	High risk	Impossible to blind the operator given the surgical nature of the treatment. For the same reason, blinding of the patient, even though it was done, does not influence the outcome of the treatment
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: "To avoid interoperative and inter‐examiner bias, all surgical procedures were performed by a single operator (SSM) and all clinical and radiographic measurements were performed by a single examiner (ARP)" Comment: insufficient information is provided regarding blinding of the outcome assessment
Incomplete outcome data (attrition bias) All outcomes	Low risk	Only 6 patients did not complete the study (4 patients for the 2 groups considered in this review)
Selective reporting (reporting bias)	Low risk	All results properly reported