Caries-related salivary parameters and oral microbial flora in patients with type 1 diabetes: A meta-analysis

This study aimed to conduct a meta-analysis by synthesising the outcomes of studies that investigated the relationship between type 1 diabetes (T1D) and salivary flow rate (SFR), salivary pH (SpH), salivary buffer capacity (SBC), streptococcus Mutans (SM), and lactobacillus (LB) counts.

The PRISMA statement guide was followed for the meta-analysis. Electronic databases were searched, and study selection and data collection processes were performed. The risks of bias in individual studies and across studies were assessed. Mean differences (MD) and Odds Ratio (OR) were used to measure the effect estimates in the comparisons.

29 studies were included in the qualitative and quantitative syntheses. Significantly higher SFR (MD = -0.22, CI: -0.26, -0.18; p < 0.001) and SpH (MD = -0.59, CI: -0.81, -0.36; p < 0.001) were observed in the healthy individuals than T1D individuals. No significant difference was observed among groups in terms of SBC (MD = 0.10, CI: -0.46,0.66; p = 0.73). An increased odds ratio of SM counts were observed regarding the T1D (OR = 3.09, 95% CI: 1.16, 8.20; p = 0.02). No association was found between LB counts and T1D (OR = 2.15, 95% CI: 0.38, 11.98; p = 0.38).

Subjects with T1D have a significantly lesser SFR and SpH than healthy individuals. But no significant difference is available in terms of SBC. Lower SM counts were observed in individuals with T1D, while no association was observed regarding LB counts. The tendency to dental caries is more likely in subjects with T1D due to lower SFR, SpH, and higher SM.