3D-Printed Zirconia With Surface Textures Enhances Bonding Performance

This study aimed to investigate the influence of textured surface design via nanoparticle jetting(NPJ) technology on bonding strength and durability of zirconia to resin Six groups of NPJ-printed zirconia with different surface textures (circular depth: 20 μm, 40 μm; circular void density: 15%, 30% and 60%) were prepared. Control groups included conventional machinable zirconia (CZ) and NPJ-printed zirconia(NZ) without surface textures. Specimens underwent sandblasting (50 μm Al2O3, 2 bar, 20 s) follow by surface characterization through SEM and contact angle measurements. After applying primer via conditioning protocols, resin cylinders (d = Ø3.5 mm × 2 mm) were bonded using dual-cure resin cement. Shear bond strength (SBS) was tested before and after 5,000 thermocycles, with data analyzed via ANOVA. All textured groups exhibited significantly higher immediate/aged SBS versus controls (P<0.05), with depth showing greater influence than void density. The 30% void density/40 μm depth group achieved the highest immediate SBS values (26.27±2.38 MPa), surpassing NZ and CZ by 40% and 80% respectively. Aged SBS values showed no intergroup differences among experimental groups (P > 0.05). Surface wettability of textured zirconia was improved through reduced contact angles. Failure analysis revealed 80-90% mixed failure (10-20% cohesive) in 30% void density/40 μm depth group, demonstrating effective mechanical interlocking. NPJ-based texturing approach significantly enhances the bonding performance and provides novel strategies for dental zirconia restorations.