Clinical research on peri-implant diseases: consensus report of Working Group 4

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.

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

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.

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.