Evaluation of association between MMP13 and MMP20 gene polymorphisms with dental caries

The aim of this study was to evaluate whether polymorphisms in MMP13 and MMP20 (SNP) were associated with dental caries. Besides, the association between development of dental caries and dietary, oral hygiene habits, amount of dental plaque accumulation, socioeconomic status were investigated. This study was conducted on 200 subjects aged between 6 and 14 years who applied for dental caries or orthodontic treatment needs. The inclusion criteria were; no systemic diseases, not using medicine, maximum plaque index level of 2 (Silness&Löe). In order to collect the information for the study, a questionnaire form was filled concerning sociodemographic status, oral hygiene habits, and the frequency of using fluoride-containing products, consuming sweet drinks and consuming sweets between meals. DMFT+dmft values and plaque accumulation scores were determined for each subject. Subjects were divided into three groups: Group 1; caries free (DMFT + dmft = 0, n=67), Group 2; moderate caries (DMFT + dmft = 1-4, n=63), Group 3; high caries (DMFT + dmft = 5≤, n=70). Unstimulated whole saliva samples were collected from each subject. After extracting the genomic DNA from saliva, genetic polymorphisms of MMP13 rs2252070 (A/G) and MMP20 rs1784418 (G/A) were genotyped using real-time polymerase chain reactions (PCR). The chi-square test and logistic regression analysis was performed for statistical investigation. A correlation was found between dental caries and variant allele frequency of MMP13 (p=0.012). A allele increased the susceptibility to dental caries. No significant correlation was found between dental caries and MMP13 genotype distribution (p=0.171). Allelic and genotype frequencies of the polymorphism in MMP20 were similar between the groups (p=0.946 and p=0.367, respectively). Consuming sweet drinks every day (p=0.039), low income level (p=0.021), education level of mother (p=0.036), using fluoride-containing products irregularly or once a day (p <0.001) increased susceptibility to dental caries. Although it was not statistically significant, low education level of father (p= 0.154), consuming sweets between meals every day (p=0.073) and visible plaque accumulation (p=0.501) increased the susceptibility of dental caries. The factors found to be correlated with dental caries development according to logistic regression analysis were; income level, using fluoride-containing products and consuming sweet drinks. In addition education level of mother were correlated with income level and the frequency of tooth brushing with using fluoride-containing products. In this study it is concluded that MMP13 polymorphism may contribute the development of dental caries. No significant correlation was found between MMP20 polymorphism and dental caries. It was also found that environmental factors such as income level, education level of mother, consumption of sweet drinks, frequency of tooth brushing and using fluoride-containing products may be correlated with dental caries development.