To develop a novel zirconia surface modification method to improve the shear bond strength of resin cement. Yttrium-stabilized tetragonal zirconia (Y-TZP) discs were cut from prefabricated ceramic blocks and polished through 1200-grit SiC abrasive. Based on the immersion time of zirconia disc in HF solution, zirconia samples were divided into four groups. Then, put samples to CaCl2 solution, dipped in NaOH solution from 20 degrees C to 80 degrees C in a water bath, kept at 80 degrees C for 2 h. After final sintering, surface appearance and chemical components were characterized with scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray diffraction (XRD), respectively. The surface roughness of discs was measured as well. Shear bond strength of zirconia to resin cement was tested and the failure mode was analyzed. Three point bending tests were done to determine the flexural strength of samples. The statistical analysis was also done for all above data. ZrO2 polycrystalline particulates were in situ synthesized on the surface of zirconia substrates. The Ra values of the four groups were 0.27 +/- 0.05 mu m, 0.89 +/- 0.34 mu m, 1.04 +/- 0.41 mu m and 1.41 +/- 0.38 mu m, respectively. The treated group was statistically significant different from the control group (p < 0.05). Shear bond strength values of the four groups were 7.88 +/- 1.94 MPa, 11.87 +/- 3.7 MPa, 17.84 +/- 6.21 MPa and 16.27 +/- 5.87 MPa, respectively, and those of I-5 and 17 were statistically different from that of C (p < 0.05). The failure mode was mainly adhesive in group C and mixed in I-5. Three point bending strength values of the four groups were 730.21 +/- 56.91 MPa, 689.81 +/- 73.75 MPa, 704.25 +/- 91.44 MPa and 702.28 +/- 86.05 MPa, respectively, without statistically significant difference between each other (p >0.05). In the conclusion, in situ synthesized polycrystalline particulates on zirconium ceramic surface can effectively improve the bonding strength of resin, avoid micro cracks and maintain the mechanical strength of ceramics. (C) 2015 Elsevier B.V. All rights reserved.