Effect of surface treatment on dentin rebonding after laser non-destructive removal of zirconia prosthesis
10.12016/j.issn.2096-1456.202440485
- Author:
LI Xiaoting
1
;
JIANG Lei
2
;
LU Zhicen
2
;
CAI Chunyan
2
;
YU Hao
2
Author Information
1. 1.School of Stomatology, Department of Prosthodontics, Hospital of Stomatology, Fujian Medical University, Fujian Key Laboratory of Oral Diseases 2.Minjiang Teachers College
2. School of Stomatology, Department of Prosthodontics, Hospital of Stomatology, Fujian Medical University, Fujian Key Laboratory of Oral Diseases
- Publication Type:Journal Article
- Keywords:
sandblasting / zirconia / dentin / Er: YAG laser / bonding strength / dentin bonding / thermal cycle / adhesive remnant index
- From:
Journal of Prevention and Treatment for Stomatological Diseases
2025;33(3):195-202
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the changes of dentin surface and the effects of different surface treatments on the rebonding effect following non-destructive restoration removal by an Er:YAG laser and to provide reference for oral clinical operation
Methods:This study was approved by the ethics review committee of the unit. Using computer-aided design and computer-aided manufacturing (CAD/CAM) technology, 102 zirconia specimens (4 mm × 4 mm × 1.5 mm) were fabricated. In total, 110 impacted third molar teeth were extracted, and 102 dentine blocks (4 mm × 4 mm × 2 mm) were prepared. The zirconia specimen and dentin blocks were bonded with resin cement before removal with an Er: YAG laser. Three disassembled dentin blocks were randomly selected, and the components of dentin surface elements were analyzed by energy dispersive X-ray spectroscopy (EDX). The removed dentin blocks were randomly divided into three groups (n = 33) based on the different surface treatments: control group (no treatment), sandblasting group (50 μm, Al2O3 sandblasting), and laser irradiation group (Er: YAG laser irradiation, parameters were set to 10 Hz, 60 mJ, 0.6 W). Three dentin blocks were randomly selected in each group for scanning electron microscopy (SEM) observation, and the residual resin on dentin surface of remaining 30 dentin blocks in each group were observed under an optical microscope at 20 times magnification. Scores were obtained using the adhesive remnant index (ARI) method. Three groups of dentin blocks (n = 30) that underwent different surface treatments were rebonded with resin cement according to standard procedures and then divided into two subgroups for aging (n = 15). One subgroup was subjected to a 37 ℃ water bath for 24 h, and the other subgroup was subjected to 5 000 thermal cycles after a 37 ℃ water bath for 24 h, and the micro-shear bonding strength of each group was measured. The microshear bonding strength of each group was measured, and fracture modes were analyzed. The differences of dentine surface ARI between the three groups, as well as the inter-group differences in fracture mode, and bonding strength, and the intra-group differences before and after aging were compared between the three groups.
Results:When zirconia was removed by Er: YAG laser, there was no obvious damage on the dentin surface, but C and Si elements in dentin increased significantly. After different surface treatments, the ARI scores of the sandblasting and laser irradiation groups were lower than those of the control group (P<0.05), while ARI was not significantly different between the sandblasting and laser irradiation groups (P>0.05). The dentin surface morphology was also different. There was a large amount of residual resin on the dentin surface of the control group. In the sandblasting group, the residual resin was lower, the dentin surface was rough, and the dentin tubules were visible. A large amount of residual resin was observed on the dentin surface of the laser irradiation group. After 24 h of water bath at 37 ℃, the bonding strengths of the control group, sandblasting group, and laser irradiation group were (6.13 ± 2.40) MPa, (9.39 ± 2.00) MPa, and (5.85 ± 1.44) MPa, respectively, and the bonding strength of the sandblasting group was significantly higher than that of the other two groups (P<0.05). After being subjected to 24 h of water bath at 37 ℃ and 5 000 thermal cycles, the bonding strengths of the control group, sandblasting group, and laser irradiation group were (5.39 ± 0.83) MPa, (8.45 ± 1.20) MPa and (4.84 ± 1.43) MPa, respectively. The bonding strength of the sandblasting group was significantly higher than that of the other two groups (P<0.05). There was no significant difference between the control group, sandblasting group, and laser irradiation group before and after 5 000 thermal cycles following 24 h of water bath at 37 ℃ (P>0.05). In the control group, sandblasting group, and laser irradiation group, cohesive fracture was not observed. The fracture mode was mainly adhesive fracture. Before and after 5 000 thermal cycles, the frequency of mixed fracture in the sandblasting group was significantly higher than that in the other two groups (P<0.05).
Conclusion:Er: YAG laser removal of zirconia does not damage dentin, but a large amount of resin remains on the dentin surface after removal. The sandblasting process can effectively remove these residual resins, thereby improving the dentine rebonding effect.
- Full text:2025031910191760861表面处理对激光非破坏性拆除氧化锆修复体后牙本质再粘接效果的影响.pdf
