Objective. To evaluate bacterial growth inhibition, mechanical properties, and compound release rate and stability of copolymers incorporated with anthocyanin (ACY; Vaccinium macrocarpon). Methods. Resin samples were prepared (Bis-GMA/TEGDMA at 70/30 mol%) and incorporated with 2 w/w% of either ACY or chlorhexidine (CHX), except for the control group. Samples were individually immersed in a bacterial culture (Streptococcus mutans) for 24 h. Cell viability (n = 3) was assessed by counting the number of colony forming units on replica agar plates. Flexural strength (FS) and elastic modulus (E) were tested on a universal testing machine (n = 8). Compound release and chemical stability were evaluated by UV spectrophotometry and 1H NMR (n = 3). Data were analyzed by one-way ANOVA and Tukey's test (α = 0.05). Results. Both compounds inhibited S. mutans growth, with CHX being most effective (P < 0.05). Control resin had the lowest FS and E values, followed by ACY and CHX, with statistical difference between control and CHX groups for both mechanical properties (P < 0.05). The 24 h compound release rates were ACY: 1.33 μg/mL and CHX: 1.92 μg/mL. 1H NMR spectra suggests that both compounds remained stable after being released in water. Conclusion. The present findings indicate that anthocyanins might be used as a natural antibacterial agent in resin based materials.

Caries is a multifactorial and transmittable disease that results mainly from bacteria present in the oral cavity. Oral microorganisms can produce metabolic acids that diffuse through dental tissues and interfaces leading to dissolution of mineral. In dentine, after mineral is dissolved, organic matrix is also exposed to breakdown by host enzymes such as matrix metalloproteinases (MMPs) that are activated by low pH followed by neutralization. This review aims to discuss the activity of different antibacterial and antiproteolytic compounds such as chlorhexidine and natural polyphenols in the control of caries progression.