Evaluation of the relationship between salivary antimicrobial peptides and severe early childhood caries in Turkish children

Early Childhood Caries (ECC) is an infectious disease that is very common among young children and can lead to various problems. Identifying caries risk in children at an early stage, preventing caries before they occur, and stopping the progression of potential caries in later stages is of great importance. Today, the effect of antimicrobial peptides found in saliva on caries risk has become a current topic of interest, yet there are only a limited number of studies on this subject involving children. In our study, we aim to compare the salivary levels of cathelicidin (LL-37), histatin-5 (HST-5), and human beta-defensin-3 (hBD-3) peptides, as well as the levels of Streptococcus mutans and Candida albicans in saliva, among a total of 50 children aged 3-6 years—specifically, those with severe early childhood caries (S-ECC) and those without any dental caries. In our study, 25 children with S-ECC were included in the study group, while 25 caries-free children formed the control group. The children underwent oral examinations, and the number of decayed, missing, and filled teeth (dmft), as well as the International Caries Detection and Assessment System (ICDAS) scores, were recorded. A questionnaire was administered to parents to evaluate their children's dietary habits, oral hygiene practices, socioeconomic factors, and birth history. Additionally, the Early Childhood Oral Health Impact Scale (ECOHIS) was used to assess the impact of caries on quality of life. Unstimulated saliva samples were collected from both groups to analyze the levels of cathelicidin LL-37, HST-5, hBD-3, Streptococcus mutans, Candida albicans, as well as salivary pH and buffering capacity. Statistical analysis was performed using IBM SPSS Statistics 22. Upon analyzing the saliva parameters, it was found that the levels of Streptococcus mutans and Candida albicans in the saliva were significantly higher in the study group compared to the control group. The levels of LL-37, hBD-3, and HST-5 antimicrobial peptides were higher in the control group than in the study group, but a statistically significant difference was observed only for LL-37 levels. A significant negative correlation was found between salivary LL-37 peptide levels and the levels of Streptococcus mutans and Candida albicans. However, no significant relationship was identified between the levels of HST-5 and hBD-3 peptides and these microorganisms. There was no statistically significant difference in saliva pH levels between the groups. However, the salivary buffering capacity was significantly lower in the study group compared to the control group. No significant correlation was found between saliva pH, buffering capacity, and dmft scores, nor between the levels of Streptococcus mutans and Candida albicans in saliva.When evaluating the survey data, no statistically significant differences were found between the groups regarding birth-related factors, socioeconomic status, dietary habits, and oral hygiene practices. Similarly, there was no significant difference between these factors and dmft scores. However, the consumption of foods or drinks containing sugar more than three times a day was significantly higher in the study group compared to the control group. Additionally, tooth brushing starting from the eruption of the first tooth was significantly lower in the study group than in the control group.No statistically significant relationship was found between dietary and oral hygiene habits and the levels of Streptococcus mutans and Candida albicans in saliva. However, in both groups, children who consumed sugary foods or drinks more than three times a day had significantly higher levels of Streptococcus mutans in their saliva. ECOHIS scores were significantly higher in the study group compared to the control group, and a significant positive correlation was found between ECOHIS scores and dmft scores. In conclusion, while our study suggests that antimicrobial peptides may be a protective factor against ECC, further studies with larger populations are needed to confirm the use of salivary antimicrobial peptides as biomarkers for caries and to determine whether their modulation may provide therapeutic benefits. Keywords: Early Childhood Caries, Histatin-5, Beta-Defensin-3, Cathelicidin LL-37, Streptococcus mutans, Candida albicans