PURPOSE: This study compared antibacterial properties of five bonding agents with that of a control, Chlorhexidine (2.5%). Products evaluated were the self-etch primers (-P) and adhesives (-A) of Clearfil SE Bond (SE-P; SE-A) [Kuraray Dental], Clearfil Protect Bond (PB-P; PB-A) [Kuraray Dental], Optibond Solo Self-etch (OS-P; OS-A) [Kerr] and the one-bottle products, self-etch Clearfil Tri-S Bond (3S) [Kuraray Dental] and total-etch Adper Scotchbond 1 XT (XT) [3M ESPE].
METHODS: Spread plates of three different bacteria (Streptococcus mutans, Lactobacillus paracasei and Actinomyces naeslundii) were prepared on Casein-peptone-Soymeal-peptone Agar (CASO-Agar). Controls, Primers, Adhesives, and Primer & Adhesive combinations were placed on standardized, sterilized filtration paper or composite disks and then placed on the inoculated agar and incubated at 37°C for 48 hours. Inhibition zones were measured and data was statistically analyzed using the Student t-test. An additional test was performed by which growth inhibiting of 1/10 and 1/100 dilutions of the test suspensions were measured spectrophotometrically as turbidity at 600nm and expressed as percentage growth (%).
RESULTS: Compared to the controls, the only cured product which produced significant inhibition was Scotchbond 1 XT (XT), and that for Actinomyces naeslundii only. The primer of Clearfil Protect Bond (PB-P) showed statistically significant growth inhibition for all three test bacteria, the primer of SE Bond (SE-P) had significant inhibitive properties against Streptoccocus mutans and Actinomyces naeslundii and the primer of Optibond Solo Self-etch (OS-P) inhibited growth of Actinomyces naeslundii significantly. CONCLUSIONS: The primers of Clearfil Protect Bond, Optibond Solo Self-etch and the product Adper Scotchbond 1 XT may be beneficial in eliminating remaining bacteria after cavity preparation, but further research on a possible long-term antibacterial benefit of these products needs to be undertaken.