DIABETES MELLITUS MAY NEGATIVELY INFLUENCE THE OUTCOME OF CONVENTIONAL NONSURGICAL ROOT CANAL TREATMENT

Subjects or Study Selection The umbrella review was developed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and registered a priori in the PROSPERO database (CRD42019141684). The literature search was conducted using multiple electronic databases (PubMed, EBSCOhost, Cochrane, and Scopus electronic databases) from inception to July 2019. Additional searches were performed using citation mining but without gray literature. This review included systematic reviews with or without meta-analysis, published only in English, and evaluating any root canal treatment outcomes comparing diabetic and nondiabetic patients. All other types of studies (eg, case reports, clinical studies, laboratory studies, animal studies, and narrative reviews) were excluded. Two reviewers independently screened titles and abstracts to identify relevant articles, and a third senior reviewer was consulted in cases of disagreement and doubt. Key Study Factor This umbrella review included 4 systematic reviews with a total of 30 primary studies (case-control, cross-sectional, and prospective longitudinal) that investigated the outcome of root canal treatment in diabetic compared with nondiabetic patients. All included reviews were published between 2016 and 2019. In addition, all included reviews performed quality assessment of the primary included studies, while only two conducted a meta-analysis. Main Outcome Measure The main outcome measure was the prevalence of persistent apical periodontitis, measured radiographically, associated with the clinical outcome of root filled teeth in diabetic compared with nondiabetic patients. A quality assessment of included systematic reviews was completed. Main Results Two out of 4 systematic reviews reported that diabetic patients had a greater prevalence of periapical radiolucencies associated with root filled teeth on radiographs. One of the 4 systematic reviews revealed a relationship between diabetes and increased frequency of loss of root filled teeth. In contrast, one systematic review concluded that there was no overall effect of diabetes on root canal treatment outcome. The quality of each individual systematic review included in the current umbrella review was appraised using "A MeaSurement Tool to Assess systematic Reviews" (AMSTAR) and categorized as "medium". Of the two previous meta-analyses carried out, one reported high heterogeneity of included studies while the other reported low heterogeneity. A meta-analysis was not conducted in this umbrella review. Conclusions Diabetes mellitus is associated with the outcome of conventional nonsurgical root canal treatment and should be considered as an important preoperative prognostic factor; however, high-quality clinical studies with improved control of confounding factors and longer follow-up are required to improve the quality of the primary studies in this area.