Role of Salivary Biomarkers in Caries Risk Assessment

Objective: This study was performed to quantify the association of salivary alpha-defensins HNP1 to -3 with caries activity in children and identify salivary defenses that may reduce or stop dental caries development. Methods: At patients' convenience, unstimulated whole saliva was collected from patients visiting the dental teaching hospital. Laboratory investigations were performed to evaluate salivary PH, α-defensin, total antioxidant, total protein, and cariogenic microorganisms' levels. After that, participants' dental records were reviewed for dental caries activity. Results: The results showed a significant association between caries activity and different salivary biomarkers (salivary pH, α-defensin, streptococcus mutans, and lactobacilli). For every one-unit increase in salivary pH, the odds of having active dental caries decreased by 89% (OR=0.11, P=0.018), and for every one-unit increase in α-defensin the odds of having active dental caries decreased by 25% (OR=0.75, P=0.004), and the odds of having active dental caries for the participant with salivary streptococcus mutans or lactobacilli levels more than or equal to 105 cfu/ml were 8.8 (OR=8.8, P=0.001) and 22 (OR=22, p≤0.001) times higher than those with levels less than 105 cfu/ml respectively. On the other hand, there were no significant associations between salivary total protein, total antioxidant, and caries activity. However, for every one-unit increase in salivary total protein, the odds of having active dental caries increased by 211% (OR=2.11, P=0.072). Conclusion: The levels of α-defensin, salivary pH, and cariogenic bacteria can be used as risk assessment markers for screening and assessing caries susceptibility.