In Situ Formation of Calcium Zirconate Particles on the Surface of High-Translucent Zirconia: A New Way to Strongly...

High-translucency zirconia (HTZ) has superior esthetic properties, but its unreliable resin bonding limits minimally invasive anterior restorations. An in situ surface modification was developed to synthesize CaZrO₃ particulates on pre-sintered HTZ for enhanced bonding durability. HTZ specimens were randomized into control (Zr-c) and calcium-modified (Zr-Ca) groups; Zr-Ca was treated with NaF/HCl mixture, calcium chloride glycerol solution, NaOH incubation (80 °C, 2 h), and sintering. Surface characteristics were characterized by SEM/EDS, AFM, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and FTIR. Flexural strength was tested via three-point bending; shear bond strength (SBS) was evaluated immediately and after 5000 thermocycles with resin cements (with/without 10-MDP). Zr-Ca showed uniform surface particulates, increased roughness, enhanced wettability, and surface Ca; XRD/FTIR/XPS confirmed CaZrO₃ and Ca-O-P species (after MDP). Zr-Ca with 10-MDP-containing resin adhesive had significantly higher SBS before/after aging (predominantly mixed failures), with flexural strength within clinical limits. In situ CaZrO₃ formation on HTZ strengthens MDP-mediated resin bonding and thermocycling resistance while preserving mechanical integrity, providing a feasible strategy for durable adhesion.