Mechanical and optical performance of crown restorations fabricated by milling and additive manufacturing

Aims: While growing demand for aesthetically pleasing, durable, and digitally compatible dental restorations increases, monolithic zirconia and three-dimensional (3D) printed permanent resin have become prominent in prosthodontics. Methods: Sixty crown specimens (n=10 per group) were fabricated from monolithic zirconia (group Z; Katana YML, A2) and a 3D-printed permanent resin (group S; Sprintray Crown, A2). Specimen received one of three surface-finishing protocols: polishing, glazing, or polishing plus glazing. Baseline surface roughness (Ra), color values, and Vickers microhardness were recorded. After thermocycling to simulate one year of clinical aging, the measurements were repeated. Data were analyzed using two-way repeated-measures ANOVA followed by Turkiye’s post-hoc test (α=0.05). Results: Group Z showed superior microhardness compared to group S (p