Early childhood caries and type 1 diabetes mellitus – Evidence on primary teeth and oral health: A systematic review

Early childhood caries (ECC) among children with type 1 diabetes mellitus (T1D) remains poorly characterized in the primary dentition (≤71 months), despite frequent reports of salivary and periodontal alterations that could plausibly increase caries susceptibility. This systematic review aimed to compare ECC prevalence and severity in children with T1D versus healthy controls and to examine associations with glycemic control, salivary parameters, periodontal indices, and preventive-care behaviors. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 and International Prospective Register of Systematic Reviews (PROSPERO) registration (CRD42024602599), we searched five databases and Google Scholar for eligible observational studies; due to substantial heterogeneity in age ranges, dentition stages, and outcome reporting, findings were synthesized narratively. Twelve studies met inclusion criteria. Evidence on caries experience in primary teeth was inconsistent, with some studies reporting higher dmft in T1D and others showing comparable or lower values than controls. In contrast, secondary outcomes showed more coherent patterns: T1D was frequently associated with reduced salivary flow, diminished buffering capacity, lower salivary pH, and early gingival inflammation, while poorer glycemic control was commonly linked to worse oral-health parameters; preventive dental attendance and fluoride-related practices were variably reported and often irregular. Overall, current evidence does not conclusively demonstrate a higher ECC burden in T1D, but consistent salivary and periodontal vulnerability supports early, integrated preventive oral-health care within pediatric diabetes management.