ORIGINAL ARTICLE Effects of air-abrasion pressure on mechanical and bonding properties of translucent zirconia Xinyan Zhang 1 & Wei Liang 2 & Feng Jiang 1 & Zonghua Wang 1 & Jiaxin Zhao 3 & Chuanjian Zhou 3 & Junling Wu 1 Received: 23 April 2020 /Accepted: 5 August 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract Objectives The purpose of this in vitro study was to investigate the effects of different air-abrasion pressures on flexural strength and shear bond strength of a translucent zirconia. Materials and methods The translucent zirconia surface was treated with 50 μm abrasive alumina particles at different pressure: 0.1 MPa; 0.2 MPa; 0.3 MPa; 0.4 MPa; 0.5 MPa; untreated specimens were used as control group (n = 33). For each group, three- point bending test was used to evaluate the flexural strength, and surface characterizations were analyzed. Following adhesive bonding and water storage for 24 h, specimens were subdivided into groups baseline and aged (5000 thermocycles). Then, shear bond strength was measured and failure mode was recorded. Statistical analysis was performed with one-way ANOVA and Tukey test (α = 0.05). Results Increasing air-abrasion pressure (0.3 MPa, 0.4 MPa, and 0.5 MPa) decreased the flexural strength. Higher air-abrasion pressure resulted in rougher zirconia surfaces and caused more microcracks. The highest shear bond strength was obtained for zirconia surfaces abraded at 0.2 MPa (15.88 ± 2.70 MPa) and 0.3 MPa (14.32 ± 1.12 MPa). Aging did not decrease the strength for all groups except control group (p < 0.001). Conclusions Air-abrasion with 50 μm abrasive alumina particles at 0.2 MPa could achieve good strength for translucent zirconia ceramics while maintaining adequate and durable bonding with resin cement. Clinical relevance A total of 0.2 MPa is recommended for air-abrasion procedure applied before a dental restoration fabricated with translucent zirconia is bonded to resin cement. Keywords Translucent zirconia . Air abrasion . Flexural strength . Bond strength Introduction Tetragonal zirconia polycrystalline with 3 mol% yttria (3Y- TZP) is extensively used in prosthetic dentistry because of the high fracture toughness and strength, and low material wear and opposing enamel wear [1–3]. However, their use in ante- rior region is limited due to the high opacity. The high opacity is mainly attributed to the tetragonal zirconia phase with an inherent birefringence, which could result in light scattering at the grain boundaries [4]. In addition, pores and additive im- purities (e.g., alumina) in zirconia ceramics with different re- fractive indices could also reduce the translucency [5]. To improve the esthetics of 3Y-TZP, porcelain has been veneered on a zirconia core [1]. However, the bilayer systems have several drawbacks, such as the complicated fabrication pro- cess and veneer chipping [6]. Monolithic translucent zirconia restorations may offer remedy to these shortcomings [7, 8]. Since 2014, more translucent zirconia with an increased Xinyan Zhang and Wei Liang are Co-first author. * Junling Wu doctorwujunling@163.com 1 Department of Prosthodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan 250012, China 2 Department of Endodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan 250012, China 3 Research Institute of Polymer Materials, School of Materials Science and Engineering, Shandong University, Jinan 250061, China Clinical Oral Investigations https://doi.org/10.1007/s00784-020-03506-y