The preparation of antibiotic polymeric dental restorative materials was carried out using inorganic antibiotic agent(Ag/Zr-phosphoric acid, AZPA) and/or chitosan. To improve the mechanical properties of microfilled dental composites, surface of silica filler was treated with γ-Methacryloxypropyltrimethoxysilane. Diametral tensile strength, flexural strength, and Knoop hardness of composites were measured. Antibiotic and antibacterial effects were also investigated. The optimum concentration of AZPA was 2~4 wt% of silica filler used based upon 60 wt% of loading onto 2,2'' -Bis-4-(3-methacryloxy-2-hydroxypropoxy)phenyl/Triethyleneglycoldimethacrylate matrix resin. Addition of chitosan to AZPA enhanced antibiotic properties of polymeric dental restorative materials.