Adhesion performance of 3D-Printed and milled titanium alloys to zirconia-based materials

Title: Adhesion performance of 3D-Printed and milled titanium alloys to zirconia-based materials

Abstract:

Background: Titanium alloys and zirconia are commonly employed in dental implants and restorations. While CAD/CAM technologies like milling and 3D printing have improved their manufacturing processes, the bonding strength between titanium abutments and zirconia crowns fabricated through different digital techniques remains underexplored.
Objective: This study aimed to evaluate the bond strength and long-term stability of titanium alloys joined with zirconia-based materials fabricated through both additive and subtractive digital manufacturing techniques
Methods: Two groups of titanium alloys (N=20) and two groups of zirconia ceramics (N=60) were fabricated using CAD-CAM milling from prefabricated discs (Ti-ML and Zr-ML) and 3D printing via selective laser melting (SLM) for titanium (Ti-3D) and DLP/LCM systems for zirconia (Zr-3D). These materials were bonded together using dental cement to create four experimental groups: Zr-ML/Ti-ML, Zr-ML/Ti-3D, Zr-3D/Ti-ML, and Zr-3D/Ti-3D. To evaluate the impact of aging, half of the specimens in each group underwent thermocycling. The study assessed density, microhardness, surface morphology, shear bond strength, and failure modes. Statistical analysis was performed using one-way ANOVA followed by Tukey’s HSD test to determine significant differences among the group
Results: The 3D-printed specimens of both titanium and zirconia demonstrated greater microhardness and surface roughness compared to their milled counterparts. Among the tested combinations, the Ti-ML/Zr-ML group exhibited the highest shear bond strength (SBS) both before and after thermocycling, and showed a higher incidence of cohesive failure. In contrast, the Ti-3D/Zr-ML group recorded the lowest bond strength.
Conclusion: The strongest adhesion between titanium and zirconia-based materials was observed when both components were produced using subtractive manufacturing methods. This was followed by combinations where both were fabricated additively, while mixed-method pairings showed comparatively weaker bonding.

Biography:

Omar Alageel is an Associate Professor in the Dental Health Department at the College of Applied Medical Sciences, King Saud University. He is a qualified dental technologist with an MSc in Dental Sciences and a PhD from McGill University in Montreal, Canada. Dr. Alageel has served as both a faculty member and a former Head of the Dental Health Department. His academic and research interests center around dental materials and advanced manufacturing technologies, particularly 3D printing. He has published numerous peer-reviewed articles in the field of 3D printing applications in dentistry and contributed a book chapter on digital restorative dentistry methodologies. Dr. Alageel’s work continues to advance the integration of digital technologies into clinical and laboratory dental practice.