“…11,47 For quantitative analysis 13 articles were included, 9 articles about third molar 8, 25, 26, 28, 29, 32, 48-50 , 2 articles about sinus lift 35, 38 and 2 articles about dental implants 46, 51 . Seventeen articles were excluded and the reasons for exclusion were as follows: 4 non-randomized controlled clinical trial 52-55 ; 4 studies which outcomes of interest were not reported [56][57][58][59] ; 2 studies that used other PRF protocol 60,61 ; 1 study which did not test PRF 62 ; 1 retrospective study 63 ; 2 prospective studies 64,65 ; 1 study that used the same patients sample as other studies 66 ; 1 full text was not found 67 ; and 1 study was written in persa and not translated 68 . The value of Kappa was 0.84, thus it was considered an excellent agreement.…”