STATEMENT OF PROBLEM: Studies focusing on the effect of zwitterionic polymer content on the physical and biological properties of additively manufactured (AM) ceramic-reinforced resin for dental applications are lacking. PURPOSE: The purpose of this in vitro study was to evaluate the effect of different concentrations of 2-methacryloyloxyethyl phosphorylcholine (MPC) on the surface properties, mechanical properties, microbial adhesion, and cellular responses of ceramic-reinforced resins. MATERIAL AND METHODS: Four different groups of AM resins filled with 60 wt% silicate-based composites and varying concentrations of MPC were prepared: 0 wt% (CRN), 1.1 wt% (CRM1), 2.2 wt% (CRM2), and 3.3 wt% (CRM3). Test specimens were fabricated from the resins using digital light processing and were tested for surface roughness (S RESULTS: CRM2 exhibited significantly lower R CONCLUSIONS: Incorporating low-concentration MPC into AM ceramic-reinforced resins significantly changed the surface properties, mechanical properties, microbial adhesion, and biocompatibility. CRM2 provided an optimal balance between structural integrity and bacterial-repellent activity while maintaining biocompatibility.