The aim of the present review was to assess randomized controlled trials (RCTs) on bone grafting procedures that included religious belief as an eligibility criterion. Indexed databases were searched up to and including February 2019 using different search strategies. In strategy 1, the following terms were used: (a) belief; (b) bone graft; (c) faith; (d) inclusion; (e) exclusion; (f) eligibility; (g) criteria; (h) randomized clinical trial; (i) religion; and (j) xenograft. In strategy 2, the following terms were used in addition to those used in strategy 1: Xenografts AND oral surgery OR xenografts AND maxillofacial OR xenografts AND dental implants. These searches were filtered using the terms "Randomized clinical trial" and "human studies". The initial search yielded 3932 studies. Filtration of results using the terms "Randomized clinical trial" and "human studies" showed 0 studies. Evaluation of patients' religious beliefs seems to be undervalued in RCTs related to the placement of xenografts. This is an essential and ethical criterion that should be taken into consideration prior to inclusion of participants and signing the informed consent form for RCTs related to the placement of bone grafts.
Keywords: Criteria; Exclusion; Inclusion; Randomized clinical trial; Religion.