BACKGROUND: Two systematic reviews have evaluated the quality of research and reporting of observational studies investigating the prevalence of, the incidence of and the risk factors for peri-implant diseases and of experimental clinical studies evaluating the efficacy of preventive and therapeutic interventions.

MATERIALS AND METHODS: For the improvement of the quality of reporting for both observational and experimental studies, the STROBE and the Modified CONSORT recommendations were encouraged.

RESULTS: To improve the quality of research in peri-implant diseases, the following were recommended: the use of unequivocal case definitions; the expression of outcomes at the subject rather than the implant level; the implementation of study validation tools; the reporting of potential sources of bias; and the use of appropriate statistical methods.

CONCLUSIONS: In observational studies, case definitions for peri-implantitis were agreed. For risk factor determination, the progressive use of cross-sectional and case-control studies (univariate analyses), to prospective cohorts (multilevel modelling for confounding), and ultimately to intervention studies were recommended. For preventive and interventional studies of peri-implant disease management, parallel arm RCTs of at least 6-months were encouraged. For studies of non-surgical and surgical management of peri-implantitis, the use of a composite therapeutic end point was advocated. The development of standard control therapies was deemed essential.