Association of salivary physicochemical characteristics and peptide levels with dental caries in children

Aim: The purpose of this investigation was to evaluate the association of physicochemical properties and antimicrobial peptide levels of saliva with caries activity in children. Materials and Methods: The required volume of unstimulated saliva was collected from 41 children aged 3–12 years with no systemic diseases. Caries activity was calculated using DMFS and dmfs records for each participating child. Collected saliva samples were then examined for their flow rate, pH, and buffering capacity. The concentration of three peptides was assessed including LL-37, human neutrophil peptide (HNP) 1–3, and human beta-defensin (HBD)-3 through an enzyme-linked immunosorbent assay. The correlation between caries activity score (CAS) and salivary variables was looked using the linear regression and Spearman's correlation method. The comparison of CAS means between high- and low-value groups of salivary items was performed using independent sample t-test while the association of CAS and salivary parameters in categorical scale was tested by Chi-square test. Results: No statistically significant differences were found between the CAS means at low and high categories of each salivary physicochemical parameter and those of antimicrobial peptides. There was a negative correlation between HNP1–3 and CAS and also between HBD-3 and CAS, but these results were not statistically meaningful. High HNP1–3 concentration was noted in 67% of the low caries rate group and 29% of the high caries rate group, with a statistically significant difference between the low and high caries rate groups (P = 0.019). Conclusion: Salivary inherent factors are not dominant determinants in caries activity. The current results may suggest that α-defensins (HNP1–3) have a protective role against dental caries.