Selective Infiltration Etching as a surface modification for high-translucency zirconia: Comparative analysis of roughness, composition, and bond strength

<ns5:p>Background Zirconia is widely regarded as a highly promising material for dental prosthetics due to its excellent biocompatibility and mechanical strength, making it an attractive alternative to metal restorations. However, its chemical inertness and high hardness pose challenges for bonding with resin cements, potentially leading to clinical debonding. Methods Thirty-six high-translucency zirconia cubes (10 × 10 × 10 mm) were randomly assigned to three groups: Group 1 – sandblasting; Group 2 – CoJet system; Group 3 – SIE. Surface roughness, morphology, and composition were assessed using a profilometer, SEM/EDX, and AFM. Following bonding with resin cement, all specimens underwent 5,000 thermocycles. Shear bond strength was then measured. Results The SIE group demonstrated significantly greater surface roughness and bond strength compared with the other groups. SEM analysis revealed that SIE generated a well-defined nanoporous surface promoting deep resin infiltration. In contrast, sandblasting and CoJet treatments produced irregular, less retentive surface morphologies. Conclusion These findings indicate that SIE provides a superior micromechanical and chemical interface, thereby enhancing the durability of zirconia–resin bonding.</ns5:p>