The effects of optimized microstructured surfaces on bond strength and durability of NPJ-printed zirconia

• Published in: Dental materials
• Main Authors: Ma, Yuhan, Wang, Huihua, Xiang, Yang, Li, Mingxing, Shen, Dongni, Zhang, Sisi, Zhou, Xiaojian, An, Jun, Shi, Ying, Fu, Baiping
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 24.09.2024
• Subjects: Finite element analysis; Morphological optimization; Nanoparticle jetting; Shear bond strength; Zirconia; Nanoparticle jetting; Zirconia; Finite element analysis; Morphological optimization; Shear bond strength
• ISSN: 0109-5641; 1879-0097; 1879-0097
• DOI: 10.1016/j.dental.2024.09.016

This study was to investigate the effects of optimized microstructured surfaces on bond strength and bond durability of the latest nanoparticle jetting (NPJ)-printed zirconia. Zirconia microstructured surfaces with different geometries and void volume were analyzed through three-dimensional finite element analysis for surface micromorphology optimization. Zirconia disks and cylinders were additively manufactured by an NPJ 3D printer (N = 128). They were randomly divided into four groups based on surface micromorphology optimization and airborne-particle abrasion (APA) treatment before they were bonded using 10-methacryloloxydecyl dihydrogen phosphate (MDP) containing resin cement (Clearfil SA luting cement). The shear bond strengths (SBSs) were tested before and after 10,000 thermocycles and were analyzed by one-way ANOVA analysis. Failure modes were determined by optical microscopy. Zirconia surfaces were analyzed with X-ray diffraction, scanning electron microscopy, and three-dimensional interference microscopy. The optimized microstructured surface was characterized by circular microstructures with 60 % void volume, about 20 µm of depths, about 10 µm of undercuts, and consistent beam widths. The optimized microstructured surface combined with APA treatment and MDP-containing resin cement possessed the highest SBSs both before and after thermocycling aging (P＜0.05). The greater reductions of zirconia bond strengths occurred when the zirconia were not treated with APA (P＜0.05). The optimized microstructured zirconia surface with circular microstructures and 60 % void volume fabricated by the latest NPJ printing technology could greatly enhance the zirconia bond strength and durability in combination with APA treatment and application of MDP-containing resin cement, which might be promising for adhesively bonded indirect restorations of NPJ-printed zirconia. •Nano-particle Jetting (NPJ) technology had high printing accuracy.•The optimized zirconia surface had circular microstructures with 60 % void volume.•APA treatment and MDP application can enhance zirconia bond performance.•The optimized microstructured surface can improve zirconia bond durability.