ObjectivesThe purpose of this paper was to systematically evaluate the effectiveness of non-surgical therapy for the treatment of peri-implant diseases including both, mucositis and peri-implantitis lesions.Material and MethodsAn electronic search in two different databases was performed including MEDLINE (PubMed) and EMBASE from 2011 to 2016. Human studies reporting non-surgical treatment of peri-implant mucositis and peri-implantitis with more than 10 implants and at least 6 months follow up published in English language were evaluated. A systematic review was performed to evaluate the effectiveness of the different methods of decontamination employed in the included investigations. Risk of bias assessment was elaborated for included investigations.ResultsTwenty-five articles were identified of which 14 were further evaluated and included in the analysis. Due to significant heterogeneity in between included studies, a meta-analysis could not be performed. Instead, a systematic descriptive review was performed. Included investigations reported the used of different methods for implant decontamination, including self-performed cleaning techniques, and professionally delivered treatment such as laser, photodynamic therapy, supra-/sub-mucosal mechanical debridement, and air-abrasive devices. Follow-up periods ranged from 6 to 60 months.ConclusionsNon-surgical treatment for peri-implant mucositis seems to be effective while modest and not-predictable outcomes are expected for peri-implantitis lesions. Limitations include different peri-implant diseases definitions, treatment approaches, as well as different implant designs/surfaces and defect characteristics.