Shear bond strength of MDP-containing light-cured veneer adhesive system to zirconia with different surface preparations Nguyen Viet Anh a , Tong Minh Son a , Vo Truong Nhu Ngoc a , Pham Thanh Ha b , Dang Trieu Hung a , Mai Hang Nga c and Nguyen Thu Tra a a School of Dentistry, Hanoi Medical University, Hanoi, Vietnam; b Deparment of Endodontics, National Hospital of Odonto-stomatology, Hanoi, Vietnam; c Institute for Translational Research in Dentistry, Kyungpook National University, Daegu, Republic of Korea ABSTRACT This study aimed to evaluate the effects of different surface prep- aration techniques on the surface microstructure, the shear bond strength (SBS) between zirconia and an MDP-containing light- cured veneer adhesive system, and the adhesive failure mode. Sixty-four zirconia specimens were divided into four groups based on surface preparation methods (n ¼ 16), including zirconia sand- blasting (ZSB), zirconia vitrification or glaze-on (ZVG), zirconia sur- face architecture technique (ZSAT), and ZSAT-ZVG combined technique (ZSATVG) groups. Sixteen lithium disilicate specimens prepared by etching with hydrofluoric acid (HF) were used as a positive control group (LDE). Surface roughness measurement and scanning electron microscopy (SEM) evaluation were performed before and after surface preparation. All specimens were then bonded with an MDP-containing light-cured adhesive system, fol- lowed by SBS testing and adhesive failure mode analysis. The ZVG and ZSATVG groups showed the greatest differential rough- ness value and microscopic irregularities, while the ZSAT and LDE groups had the least surface change but the most micromechani- cal retentive structures for resin infiltration. SBS values were sig- nificantly different among groups (p < 0.001) with the highest SBS observed in the ZSAT group, followed by the ZSB group, LDE group, ZSATVG group, and lastly, the ZVG group. There was a statistically significant difference in failure types among the sur- face preparation groups (p < 0.001). The ZSAT group had the highest frequency of mixed failure, followed by the ZSB group, LDE group, and the ZSATVG and ZVG groups. Establishing direct micromechanical retention within zirconia itself yields a higher bond strength than indirect micromechanical retention within a glass ceramic layer. ARTICLE HISTORY Received 19 March 2023 Revised 27 November 2023 Accepted 1 December 2023 KEYWORDS Zirconia; surface preparation; glaze-on; light- cured cement; vitrification CONTACT Vo Truong Nhu Ngoc nhungoc@hmu.edu.vn School of Dentistry, Hanoi Medical University, Hanoi, Vietnam. � 2023 Informa UK Limited, trading as Taylor & Francis Group JOURNAL OF ADHESION SCIENCE AND TECHNOLOGY https://doi.org/10.1080/01694243.2023.2293382