Anti-Bacterial Properties of Adhesive Resins and Glass-Ionomers

Objectives: The primary role of bacteria in the progression of oral disease is well established. Many antimicrobial products exist and are used regularly in dental treatment and prevention.As an adjunct therapy, antibacterial restorative materials would be beneficial. This study examined ten restorative materials to determine any antibacterial effect against Streptococcus mutans, Actinomycetes viscosus and Porphyomomas gingivalis. Methods: 1. Agar plates were streaked with bacterial cultures and standardised sterile discs of each material placed on the surface. The plates were incubated and inhibition zones measured. 2. Discs of the materials that produced inhibitory zones against S. mutans were placed in 1.0ml of broth culture and incubated. Dilution series were prepared from the broths and streaked onto agar plates, and colony growth counted and compared against control plates. Results: The inhibition zones for S. mutans were greatest with Prompt-L-Pop, with an average zone of 7.5mm, compared with 5.0mm, 3.5mm and 3.0mm for Vitrebond, Singlebond and Kuraray ABF respectively. The bonding agents produced larger average inhibitory zones when uncured. All other materials had no effect on S. mutans. With A. viscosus, Prompt-L-Pop produced the largest average inhibition, 6.0mm, compared with Kuraray ABF, 2.0mm and Singlebond, 1.0mm. All materials produced some inhibition with P. gingivalis with bonding agents (12.0 mm) and Vitrebond (6.0mm) most effective. In the dilution series, Singlebond and Kuraray ABF produced an average three log reduction in S. mutans colony numbers. Prompt-L-Pop caused an average four log reduction and Vitrebond an average two log reduction in growth. Conclusions: The results of this study indicate restorative dental materials demonstrate a range of antibacterial properties. This may provide a short term clinical potential for reduction in plaque formation adjacent to restorations. The long term effects are yet to be determined. This project was supported by the Australian Dental Research Foundation.