Abstract The aim of this review is to summarize the evidence on associations between diabetes mellitus (DM) and complications around dental implants. Electronic database searches of MEDLINE, EMBASE, JBI Database of Systematic Reviews and Implementation Reports, Cochrane Database of Systematic Reviews and the PROSPERO register were performed from 1990 up to and including May 2018, using MeSH terms and other keywords. Systematic reviews and meta-analyses investigating the associations of DM and implant complications (failure, survival, bone loss, peri-implant diseases, and post-surgery infection) were eligible. The quality of the included reviews was determined using the Assessment of Multiple Systematic Reviews Tool 2 (AMSTAR 2). Twelve systematic reviews were included. Implant survival rates ranged from 83.5% to 100%, while implant failure rates varied from 0% to 14.3% for subjects with DM. The three meta-analyses performed for event “implant failure” reported no statistically significant differences between diabetic and non-diabetic subjects. An apparently increased risk of peri-implantitis is reported in patients with DM. According to the AMSTAR 2 classification, 50% of the reviews were classified as being of “critically low”, 25% as of “low” and 25% as of “moderate” quality. Evidence indicates high levels of survival and low levels of failure of implants inserted in patients with DM. However, DM was assessed as a whole in the majority of studies and, the actual influence of hyperglycemia on implant survival/failure is still uncertain. DM/hyperglycemia seems to be associated with a high risk of peri-implantitis. However, this conclusion is based on a limited number of systematic reviews.

Abstract The aim was of this study was to determine the current weight of evidence for the existence of specific differences between the microbiota of healthy teeth and healthy implants, or of teeth with periodontitis and implants with peri-implantitis. A systematic review was conducted according to the PRISMA statement. The MEDLINE, EMBASE and Cochrane databases were searched up to February 2018 for studies comparing microbiological data of biofilm samples collected from healthy teeth and implants or from teeth with periodontitis and implants with peri-implantitis. The weight of evidence was defined in three categories (strong, moderate and mild/some), according to the difference in number of studies showing statistically significantly higher counts and/or proportions and/or abundance and/or prevalence of microorganisms in health or in disease. Of the 132 articles identified, 8 were included. A wide range of microorganisms were present in different conditions but no microorganisms showed strong, moderate or mild/some evidence for a specific association with either teeth or implants. The results of this systematic review indicated that there is insufficient evidence in the literature to support specific differences between microorganisms colonizing teeth and implants, either in health or in disease.