The relationship between dental caries and salivary mucin

Abstract

Background: The World Health Organization (WHO) has announced that dental caries is the leading oral disease in children, and it is a chronic infectious disease derived by multiple causes. The vision of WHO is to hold that the dental caries score in 12-year-old children have to lower than 1.5 DMF/t by 2025. Saliva is the main test and biomarker of high research importance, which is an internal factor of dental caries. Despite the fact that salivary proteins are a very small part of the composition, they play a role in inhibiting the growth of caries-causing bacteria and enamel demineralization and remineralization. For example, salivary mucin accounts for 20-30% of the total protein in saliva and is the most commonly studied. In 2018, in 6-and 12-year-old children in India, and in 2015 in Thailand, 9-11-year-old children, the saliva flow rate and salivary MUC5B and MUC7 proteins were found to be related to dental caries in children. Aim: The aim of this study was to assess the relationship between the dental caries and salivary mucin. Materials and Methods: The study population was consisted of 190 children aged 12 years old, studying 84th secondary school. We obtained according to the informed consent No.2022/3-03-36 of the Ethical Committee. The oral examination was done according to the recommendation of WHO, 2013. Saliva sample was collected between 9:00 AM and 11:00 AM. All children abstained from eating and drinking 2 h. Salivary mucin protein was analyzed by Sunlong Biotech Co., Ltd. Human Mucin-5B, Mucin-7, ELISA Kit (SL1210Hu, SL1211Hu) in the Medical Pathology Laboratory of MNUMS. Results: The prevalence and DMF/t score of dental caries were 88.6% and 2.79 among all children. The unstimulated salivary flow rate were 0.34±0.2 ml/min among selected children, 0.41±0.22 ml/min in control-I group, 0.36±0.19 ml/min in control-II group and 0.26±0.17 ml/min in the case group (p<0.05). The mean concentrations of MUC7 and MUC5B amounted to 0.38±0.22 ng/ml and 0.31±0.09 ng/ml in the control I group, 0.42±0.19 ng/ml and 0.35±0.11 ng/ml in the control II group, 0.45±0.07 ng/ml and 0.38±0.13 ng/ml in control group, respectively (p<0.001). Unstimulated salivary flow rate was significantly difference between groups (p=0.018), but concentration of salivary MUC5B (p=0.96) and MUC7 (p=0.78) glycoproteins was no significantly difference. Conclusion: 1. Among 190 12-year-old children who participated in the study, caries prevalence was 88.6%, and the intensity index was 2.79. 2. The rate of saliva secretion at rest in all children was 0.34±0.2 ml/min, while it was 0.41±0.22 ml/min in the control group I, 0.36±0.19 ml/min in the control group II, and 0.26±0.17 ml/min in the case group (p<0.05). was 3. A weak and inverse correlation was observed between caries and saliva secretion rate in children, while a weak and direct correlation was observed between caries and MUC5B and MUC7 proteins in saliva.