University Medical Center Groningen, The University of Groningen, Center for Dentistry and Oral Hygiene, Department of Restorative Dentistry and Biomaterials, Groningen, the Netherlands.
University Medical Center Groningen, The University of Groningen, Center for Dentistry and Oral Hygiene, Department of Restorative Dentistry and Biomaterials, Groningen, the Netherlands; St. Antonius Hospital Nieuwegein, Department of Oral-Maxillofacial Surgery, Prosthodontics and Special Dental Care, Nieuwegein, the Netherlands; University Medical Center Utrecht, Department of Oral-Maxillofacial Surgery, Prosthodontics and Special Dental Care, Utrecht, the Netherlands.
J Mech Behav Biomed Mater. 2020 Oct;110:103906. doi: 10.1016/j.jmbbm.2020.103906. Epub 2020 Jun 6.
The objectives of this study were to compare the in vitro, laboratory aging, fracture strength, failure mode and reparability of molars restored with lithium disilicate inlays and overlays in conjunction with or without immediate dentin sealing (IDS).
Forty extracted, sound human molars were selected and divided into four groups: 1) Inlays with IDS; 2) Inlays without IDS; 3) Overlays with IDS; 4) Overlays without IDS. Standard MOD preparations were made (3 mm wide, 5 mm deep) and in groups 2 and 4, all the cusps were reduced by 2 mm. Directly following tooth preparation, IDS was applied in specimens belonging to groups 1 and 3. The indirect restorations were luted with a heated composite. The restored teeth were subsequently challenged during aging (1.2 million cycles) and thermocycling loading (8000 cycles, 5-55 degrees C). Subsequently, the fracture strength was tested by a load to failure test at 45°. A failure analysis was performed using light- and scanning electron microscopy. The results were analyzed using two-way ANOVA and a Fisher exact test.
Mean fracture load + SD (N) were: Group 1 (n = 12): 1610 ± 419; Group 2 (n = 12): 1115 ± 487; Group 3 (n = 12): 2011 ± 496; Group 4 (n = 12): 1837 ± 406. Teeth restored with an onlay were stronger than those restored with an inlay restoration (p < .001). Teeth with IDS were stronger overall than those without IDS (p = .026). The interaction between preparation type and the mode of dentin conditioning had no statistically significant influence on fracture strength (p = .272). Subsequently, custom hypothesis tests showed that there was no statistically significant difference in fracture strength between inlays with IDS and overlays without IDS (p = .27). Overlays tend to fail in a more destructive, non-reparable way (p = .003).
Both variables IDS and overlay preparation improve overall fracture strength. Inlays with IDS and overlays without IDS didn't differ in fracture strength. Both inlays and overlays are strong enough to withstand physiological chewing forces.
本研究的目的是比较在体外、实验室老化、断裂强度、失效模式和可修复性方面，用锂硅玻璃陶瓷嵌体和贴面修复结合或不结合即刻牙本质封闭（IDS）的磨牙。
选择 40 颗提取的、完好的人磨牙，分为四组：1）有 IDS 的嵌体；2）无 IDS 的嵌体；3）有 IDS 的贴面；4）无 IDS 的贴面。制备标准 MOD 预备（3mm 宽，5mm 深），在组 2 和组 4 中，所有牙尖均被磨除 2mm。在牙体预备后，立即对属于组 1 和组 3 的样本进行 IDS 处理。用加热复合树脂粘固间接修复体。随后，在老化（120 万次循环）和热循环加载（8000 次循环，5-55°C）后对修复牙进行测试。随后，在 45°进行破坏载荷试验测试断裂强度。用光镜和扫描电镜进行失效分析。使用双因素方差分析和 Fisher 确切检验对结果进行分析。
平均断裂载荷+SD（N）为：组 1（n=12）：1610+419；组 2（n=12）：1115+487；组 3（n=12）：2011+496；组 4（n=12）：1837+406。用贴面修复的牙齿比用嵌体修复的牙齿强度更高（p<.001）。有 IDS 的牙齿总体上比没有 IDS 的牙齿强度更高（p=0.026）。预备类型和牙本质处理方式之间的相互作用对断裂强度没有统计学显著影响（p=0.272）。随后，定制假设检验显示，有 IDS 的嵌体和无 IDS 的贴面之间的断裂强度没有统计学显著差异（p=0.27）。贴面更容易以更具破坏性、不可修复的方式失效（p=0.003）。
IDS 和贴面预备这两个变量都可以提高整体断裂强度。有 IDS 的嵌体和无 IDS 的贴面在断裂强度方面没有差异。嵌体和贴面都足以承受生理咀嚼力。
