Antibacterial Activity of Dental Adhesive System: An invitro study

The development of caries is dependent on the interaction of four primary factors: tooth surface, diet, time, and the presence of oral bacteria. Bacteria are the main cause of secondary caries, which develop as a result of failures in resin composite restorations. Objective: The purpose of this study was to investigate the efficacy of antimicrobial dental bonding agent, Clearfil^TM SE Protect on planktonic and biofilm oral bacteria. Methods: Clearfil^TM SE protect bond (SEP) which contains MDPB, an antimicrobial agent and SE bond (SE) dental adhesive agents were purchased from Kuraray Inc. ATCC strains of Streptococcus mutans 31377, S. gordonii 10558, Enterococcus faecalis 11700, and Actinomyces viscosus 19246 were cultured for 24 hours and also 7 day old mixed biofilm of these bacteria were prepared in a 48-well culture dish. A stock 1% solution of SEP and SE primer was prepared in PBS. Minimal bactericidal concentration was determined by adding 0.1 ml of diluted SEP or SE to bacteria (1x10⁵). Biofilm bacteria (2x10⁶ cells) were incubated with conditioned media (CM) from UV-cured and un-cured discs of SEP and SE (5-120 minutes) and bacterial viability was tested by MTT assay. Results: Clearfil SEP displayed bactericidal properties at highest dilutions (1/4096) while Clearfil SE showed very little. More than 80% of the bacteria were killed in 60 minutes compared to less than 30% with SE. Biofilm-grown bacteria also found to be susceptible to SEP-CM. Only 780 viable bacteria were detected after treatment with CM prepared from SEP discs, compared to 8.22x10⁵ viable bacteria with SE-CM. Conclusion: Clearfil^TMSEP composite with MDPB proved to be highly antimicrobial against planktonic and biofilm oral bacteria and may aid in prevention of secondary caries.

Supported by the UTHSC College of Dentistry Alumni Endowment Fund and the Tennessee Dental Association Foundation