Caroliene Meijndert

120 Chapter 7 The following study criteria were handled: Inclusion criteria: − Human subjects included in the studies should be ≥ 18 years of age; − Titanium, bone level implants; − Implants supporting single crowns placed in the anterior region of the maxilla (second premolar to second premolar); − Only healed sites (at least 3 months healing time after extraction); − Follow-up of at least 1 year after implant placement; − Detailed information on bone level changes measured on peri-apical radiographs; − Randomized clinical trials or prospective clinical studies with a minimum sample of 10 participants per study-group. Exclusion criteria: − External implant-abutment connections; − No details of the implant type; − Did not report bone level changes; − Bone level measurements obtained with cone beam computer tomography (CBCT) or orthopantomograms; − Animal studies, in vitro studies, retrospective studies, reviews. Study selection Two reviewers (C.M.M., H.J.A.M.) independently screened the results from the electronic searches, according to the inclusion and exclusion criteria, in two rounds. Articles were first screened by title and abstract. In case of disagreement or doubt, the study was moved to the next round (full text assessment). The Cohen’s κ and percentage of agreement were calculated to determine the measure of agreement between the two reviewers. Any disagreement regarding the inclusion was resolved by a consensus discussion. In case of persistent disagreement, an external independent reviewer (G.M.R) with experience in implant dentistry could be consulted. Quality assessment Methodological quality and risk of bias were assessed using the Cochrane risk of bias tool (RoB 2.0) (Sterne et al., 2019) for randomised controlled trials and the ROBINS-1 tool (Sterne et al., 2016) for prospective clinical non-randomised trials by the same two reviewers (C.M.M., H.J.A.M.), independently. Any disagreement was resolved by consensus between the reviewers.