Enhancing zirconia-porcelain bond: Effects of additively manufactured surface textures, surface treatment, veneering workflow and thermocycling

Porcelain-veneered zirconia restorations are prone to chipping. While airborne-particle abrasion (APA) enhances zirconia-porcelain bond, it risks substrate damage. This study introduces a non-destructive alternative utilizing engineered surface textures (30%, 50%, and 70% protrusions) on zirconia fabricated via Advanced Customized Jetting (ACJ) to improve adhesion. The effects of additively manufactured textures, APA, veneering workflow (hand-layered feldspathic porcelain vs. heat-pressed lithium disilicate), and thermocycling on shear bond strength (SBS) and failure modes were evaluated. Results indicated that surface textures significantly enhanced SBS (P < 0.001) compared to non-textured controls. The combination of protrusion designs (both 30% and 70%) with the heat pressing workflow and no thermocycling, yielded optimal bond strength. Conversely, the specific APA protocol tested showed no significant effect on surface morphology (P = 0.465) and a much weaker effect on SBS (η 2 p = 0.015, P = 0.035) compared to surface textures (η 2 p = 0.604, P < 0.001). The integration of surface textures and veneering workflow significantly influenced failure mode distributions (P < 0.001), with textured and hand-layered groups reducing adhesive failure rates. These findings suggest that ACJ-fabricated surface textures, as a non-destructive and highly effective method, may offer a potential alternative to APA for enhancing the zirconia-porcelain interface.