Methods for assessing peri-implant marginal bone levels on digital periapical radiographs: a meta-research

OBJECTIVES This meta-research assessed methodologies used for evaluating peri-implant marginal bone levels on digital periapical radiographs in randomized clinical trials published between 2019 and 2023. METHODS Articles were searched in four databases. Data on methods for assessing peri-implant marginal bone levels were extracted. Risk of bias assessment was performed. RESULTS During full-text reading, 108 out of 162 articles were excluded. Methodological issues accounted for these exclusions, including the absence of radiograph-type information, the lack of radiographic positioners, the missing anatomical references, and the use of panoramic radiographs or tomography. Fifty-four articles were included, most from Europe (70%) and university-based (74%). Radiographic positioners were specified in 54% of articles. Examiner calibration was unreported in 54%, with 69% lacking details. In 59%, no statistical measure assessed examiner agreement. Blinding was unreported or unused in 50%. Marginal bone level changes were the primary outcome of 61%. Most articles (59.3%) raised "some concerns" regarding bias, while 37% showed a high risk of bias, and only two articles (3.7%) demonstrated a low risk of bias. CONCLUSIONS Several limitations and areas for improvement were identified. Future studies should prioritize protocol registration, standardize radiographic acquisitions, specify examiner details, implement calibration and statistical measures for agreement, introduce blinding protocols, and maintain geometric calibration standards.