1.The effect of Er: YAG laser irradiation on bonding properties of IPS e.max CAD ceramics
HOU Yepo ; SHEN Renze ; CHEN Luyuan ; CHEN Yi ; JIANG Yingtong ; LI Jingmei ; GAO Jie
Journal of Prevention and Treatment for Stomatological Diseases 2018;26(2):95-98
Objective:
To investigate different Er:YAG laser power settings on the bonding properties of IPS e.max CAD ceramics.
Methods :
96 IPS e.max CAD ceramics blocks (5 mm × 5 mm × 5 mm) were prepared and randomly divided into 8 groups (n = 12), the untreated blocks served as the control, while one of the experimental groups was treated with 4.5% HF for 20 seconds, six remaining test group (C、D、E、F、G、H) were treated with different Er: YAG laser power settings: 100 mJ、200 mJ、300 mJ、400 mJ、500 mJ and 600 mJ. Morphology of the ceramic surface was observed by atomic force microscopy and its shear bond strength (SBS) was tested.
Results :
Higher shear bond strength values were found in group C-H compared to group B, the highest is group F (24.12 ± 1.91) MPa. The difference was statistically significant. The atomic force microscope observation of the surface structure showed that the control group was smooth and flat, and the HF-like etching group formed a uniform needle-like convex structure. The laser group gradually formed a regularly arranged cylindrical convex structure, in which the surface of the G and H groups was damaged.
Conclusion
The Er: YAG laser power settings of 400 mJ can be used as an effective pretreatment method before bonding of IPS e.max CAD ceramic.