Picosecond laser-induced different patterned surface modification of dental zirconia ceramics and its effect on bonding properties
ZHOU Qiaozhen1, CHEN Rui2, LUO Yixuan3, ZHU Li1, WANG Siqian1, LIU Zhucheng2, MA Jianfeng1.
1.Department of Prosthodontics, School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou 325027, China; 2.Zhejiang Jingyao Optoelectronic Technology Company Limited,Shaoxing 311800, China; 3.Department of Stomatology, Dongyang People’s Hospital, Jinhua 322100, China
ZHOU Qiaozhen,CHEN Rui,LUO Yixuan, et al. Picosecond laser-induced different patterned surface modification of dental zirconia ceramics and its effect on bonding properties[J]. JOURNAL OF WEZHOU MEDICAL UNIVERSITY, 2024, 54(6): 431-437,445.
Abstract：Objective: To compare the effects of different patterned picosecond laser scanning on the surface treatment of zirconia by evaluating the bonding strength with self-adhesive resin cement. Methods: 160 sintered zirconia ceramic specimens were randomly divided into 8 study groups and treated as follows. Blank control (group A); Sandblasting control (group B); Picosecond laser treatment groups (group C-H), according to the different patterned picosecond laser scanning on the surface treatment of zirconia, divided to the following groups:picosecond laser honeycomb scanning (group C); honeycomb scanning with picosecond laser after alumina sandblasting (group D); picosecond laser transverse linear scanning (group E); picosecond laser transverse linear scanning after alumina sandblasting (group F); picosecond laser trellis scanning (group G); picosecond laser grid scanning after alumina sandblasting (group H). Scanning electron microscope was used to observe the microstructure of the samples, atomic force microscope was used to measure the surface roughness, X-ray diffractometer was used to observe the transformation of crystal phase composition on the surface, the electronic universal testing machine was used to measure the three-point bending strength and the shear bond strength (SBS) of zirconia samples and self-adhesive adhesive resin cement, the optical microscope was used to observe the fracture surface to judge the fracture mode. All data were analyzed by SPSS 26.0 software. Results: After picosecond laser scanning on the surface of zirconia ceramic, the honeycomb shape, parallel and equal spacing horizontal line pattern and criss-crossing and equal spacing tic-tac-toe pattern can be obtained. Different roughness was obtained, group F showed the largest roughness, which was 14.92 μm. Laser surface treatment does not lead to surface crystal phase transformation. The shear bond strength increased obviously after picosecond laser patterning treatment (P<0.05).The bonding strength of group C was the highest (26.86±1.53)MPa, which was about 7.4 times of group A. The fracture mode changed from complete bond failure of group A and group B to cohesive failure and mixed failure.The lowest flexural strength of the zirconia ceramic after laser treatment still met the requirements of clinical application. Conclusion: Patterning the surface of zirconia with picosecond lasers can improve the shear bond strength between zirconia and the resin cement, which is a promising surface modification method for zirconia.
