Biomimetic nanosilica-lithium infiltration enhances the bonding durability of high translucent zirconia to resin

Achieving a long-term, durable bond to zirconia remains a significant clinical challenge due to its chemically inert surface. In this study, we used a novel nanosilica-lithium infiltration (SI) strategy as an alternative method for modifying the surface of high translucent zirconia. This approach created a well-integrated, silica-rich reactive interface, offering a more efficient and conservative method that preserves the crystalline stability of high translucent zirconia. We compared surface characteristics and shear bond strength (SBS) before and after artificial aging for four treatment groups: no treatment (NT), SI, airborne-particle abrasion (APA), and SI followed by APA (SI-APA). Our findings demonstrated that this SI method produced a homogeneous, well-integrated, silica-rich layer (approximately 12 μm thick, with 2 μm of subsurface penetration). This layer significantly increased surface roughness (Ra SI = 0.86 ± 0.01 μm, Ra NT = 0.40 ± 0.01 μm; P < 0.05) without causing a phase transformation, whereas the APA group caused approximately 2% monoclinic transformation. Although the APA group exhibited the highest immediate SBS (20.67 ± 3.28 MPa), the SBS value decreased significantly after aging (12.39 ± 3.83 MPa, P < 0.05). Conversely, the SI group combined with 10-methacryloyloxydecyl dihydrogen phosphate (MDP)/silane-containing primer exhibited the highest post-aging SBS (16.83 ± 1.53 MPa), which was similar to that before aging (16.99 ± 1.39 MPa, P＞0.05). Evidence from micro-topographical and spectroscopic analyses confirmed that this enhanced bond stability resulted from the synergistic effects of optimized surface wettability, mechanical interlocking, and chemical coupling. In conclusion, the nanosilica-lithium infiltration technique provides a feasible and less destructive solution for significantly enhancing the long-term bonding reliability of high translucent zirconia in clinical applications. • Nanosilica–lithium infiltration creates a uniform 12 μm silica-infiltrated layer on zirconia. • The method prevents detrimental phase transformation in high translucent zirconia. • Modified zirconia shows significantly improved bond strength and long-term durability to resin cements. • Enhanced aging durability is achieved via mechanical retention, optimized wettability, and chemical adhesion.