Formation of Cariogenic Bacterial Biofilm on Vanillin-Incorporated Resin-Based Dental Sealant

Abstract

Tooth decay or dental caries is an important oral health problem involving people of all age groups. The disease is the outcome of the demineralize process in which aciduric and acidogenic bacteria in a biofilm decompose tooth structure. Dental sealant, a resin material, which is applied on the occlusal pit and fissure surfaces of the teeth as a protective layer has been commonly used to prevent dental caries. However, the microbial effect on food residue is found to be a major cause of microleakage of sealant and secondary caries. Several types of antimicrobial agents were introduced to increase the caries preventive effect of dental sealants. Vanillin, the main component of flavoring agent vanilla, has been found to have antimicrobial property against Gram-positive and Gram-negative bacteria. The objective of this study was to investigate the antimicrobial effect of vanillin-incorporated dental sealant against biofilm formation of cariogenic bacteria. Dental sealant resin samples (Clinpro; 3M ESPE, USA) were prepared in 96-well plate in accordance with the amount of vanillin adding (0%, 0.5%, 1% and 5% vanillin). The cariogenic bacterial suspensions of Streptococcus mutans ATCC 25175 and Lactobacillus casei ATCC 334 were added to saliva-coated samples and incubated at 37°C in 5% CO2 atmosphere for 48 h to allow the biofilm formation. The quantity of vital biofilm was determined by WST Microbial Cell Counting Kit (Dojindo Molecular Technologies, USA) at 460 nm. One-way ANOVA and Tukey’s test were applied to the statistical analysis. A significant inhibitory effect against L. casei biofilm was observed in all vanillin incorporated samples (0.5%, 1% and 5% vanillin) compared with samples without vanillin. The percentage of biofilm reduction was 32-39%. For S. mutans, the suppressive effect was noticed only at >1% vanillin with 18-25% biofilm reduction. In conclusion, the incorporation of vanillin to dental sealants could decrease biofilm formation of cariogenic bacteria (S. mutans and L. casei). The use of dental sealants containing vanillin could be a promising measure to prevent dental caries due to their antibacterial biofilm formation property.