Background: The antibacterial properties are beneficial and desired for dental restorative composite materials. The incorporation of various antimicrobial agents into resin composites may compromise their physical and mechanical properties hence limiting their applications.
Objective: The aim of the current study is to evaluate the antibacterial activity and the hardness of microhybrid and flowable resin based composites (RBCs) modified using novel antimicrobial agent chitosan (CS).
Methods: The antibacterial activity of microhybrid and flowable RBCs modified with 0, 0.25, 0.5 and 1% w/w chitosan (CS) against Actinomyces viscous bacteria was explored using agar diffusion test and direct contact methods. The hardness of control and experimental RBCs was determined by Vickers hardness (VH) tester.
Results: The results revealed that control and experimental flowable and microhybrid RBCs did not demonstrate growth inhibition zone in the lawn growth of Actinomyces viscous. The direct contact test revealed that colony forming unit (CFU) count of Actinomyces viscous was comparable among the experimental and control materials. The flowable RBCs containing 1% CS had significantly higher VH compared to control and other experimental flowable RBC groups. The microhybrid RBCs consisting of 0.50% CS exhibited significantly higher VH compared to experimental microhybrid RBC group containing 1% CS.