Shear bond strength, finite element analysis, flexural strength and accuracy analysis of additively manufactured bio-inspired 3Y-TZP for dental applications

Weak shear bond strength (SBS) has always been a challenge for clinical bonding of 3mol% yttria-stabilized tetragonal zirconia (3Y-TZP). With the development of additive manufacturing technology, vat photopolymerization (VPP) is an alternative that allows zirconia to form precise complex structures and achieve bionic structure molding based on the natural advantages of different organisms in relation to biological structure, microstructure, and mechanical behavior. As report goes, the toe structure of tree frog can effectively achieve friction enhancement on humid and flooded surfaces. In this paper, we present a new type of 3Y-TZP material loaded with tree -frog bionic structures via VPP additive manufacturing to improve SBS between resin cement and 3Y-TZP for clinical requirements. And flexural strength, finite element analysis and accuracy analysis of bioinspired 3Y-TZP is carried out to verify its feasibility of clinical application. The SBS of the bio-inspired group with 250 mu m width and 250 mu m height reached a maximum of 22.7 +/- 1.3 MPa before hydrothermal aging, the flexural strength of the bio-inspired group with 250 mu m width and 150 mu m height decreased the least, reaching 825 +/- 30 MPa, and the accuracy analysis of the central -incisor veneer restoration loaded with the bionic structures showed that the average deviation value was 0.033 +/- 0.036 mm. This study has found that these bionic structures can effectively improve the SBS of the interface between zirconia and resin cement, while flexural strength and accuracy can also meet requirements of clinical dental application.