Deptartment of Prosthodontics, Nova Southeastern University College of Dental Medicine, Ft. Lauderdale, FL.
Nova Southeastern University College of Dental Medicine, Ft. Lauderdale, FL.
J Prosthodont. 2020 Mar;29(3):207-218. doi: 10.1111/jopr.12716. Epub 2018 Jan 14.
To test the impact of exposure to artificial gastric acid combined with toothbrush abrasion on the properties of dental ceramics. Earlier research has indicated that immersion in artificial gastric acid has caused increased surface roughness of dental ceramics; however, the combined effects of acid immersion and toothbrush abrasion and the impact of increased surface roughness on mechanical strength and optical properties have not been studied.
Three commercially available ceramics were chosen for this study: feldspathic porcelain, lithium disilicate glass-ceramic, and monolithic zirconium oxide. The specimens (10 × 1 mm discs) were cut, thermally treated as required, and polished. Each material was divided into four groups (n = 8 per group): control (no exposure), acid only, brush only, acid + brush. The specimens were immersed in artificial gastric acid (50 ml of 0.2% [w/v] sodium chloride in 0.7% [v/v] hydrochloric acid mixed with 0.16 g of pepsin powder, pH = 2) for 2 minutes and rinsed with deionized water for 2 minutes. The procedure was repeated 6 times/day × 9 days, and specimens were stored in deionized water at 37°C. Toothbrush abrasion was performed using an ISO/ADA design brushing machine for 100 cycles/day × 9 days. The acid + brush group received both treatments. Specimens were examined under SEM and an optical microscope for morphological changes. Color and translucency were measured using spectrophotometer CIELAB coordinates (L*, a*, b*). Surface gloss was measured using a gloss meter. Surface roughness was measured using a stylus profilometer. Biaxial flexural strength was measured using a mechanical testing machine. The data were analyzed by one-way ANOVA followed by Tukey's HSD post hoc test (p < 0.05).
Statistically significant changes were found for color, gloss, and surface roughness for porcelain and e.max specimens. No statistically significant changes were found for any properties of zirconia specimens.
The acid treatment affected the surface roughness, color, and gloss of porcelain and e.max ceramics. The changes in translucency and mechanical strength for all materials were not statistically significant. Zirconia ceramic showed resistance to all treatments.
测试人工胃酸暴露与牙刷磨损联合作用对牙科陶瓷性能的影响。早期研究表明，浸泡在人工胃酸中会导致牙科陶瓷表面粗糙度增加；然而，酸浸泡和牙刷磨损的联合作用以及表面粗糙度增加对机械强度和光学性能的影响尚未得到研究。
本研究选用三种市售陶瓷：长石质瓷、锂硅玻璃陶瓷和整体氧化锆。将试件（10×1mm 圆盘）切割、按要求热处理并抛光。每种材料分为四组（每组 8 个试件）：对照组（不暴露）、仅酸处理组、仅牙刷处理组、酸+牙刷处理组。将试件浸入人工胃酸（50ml 0.2%[重量/体积]氯化钠、0.7%[体积/体积]盐酸和 0.16g 胃蛋白酶粉末，pH=2）中 2 分钟，用去离子水冲洗 2 分钟。每天重复 6 次×9 天，试件在 37°C 下保存在去离子水中。用 ISO/ADA 设计的刷牙机进行牙刷磨损试验，每天 100 次×9 天。酸+牙刷组接受两种处理。用扫描电子显微镜和光学显微镜观察试件的形态变化。用分光光度计 CIELAB 坐标（L*、a*、b*）测量颜色和半透明度。用光泽计测量表面光泽度。用触针式轮廓仪测量表面粗糙度。用机械试验机测量双轴弯曲强度。采用单因素方差分析，然后进行 Tukey 事后 HSD 检验（p<0.05）对数据进行分析。
在瓷和 e.max 试件中，颜色、光泽度和表面粗糙度均发生了统计学显著变化。在氧化锆试件的任何性能中均未发现统计学显著变化。
酸处理影响了瓷和 e.max 陶瓷的表面粗糙度、颜色和光泽度。所有材料的半透明度和机械强度变化均无统计学意义。氧化锆陶瓷对所有处理均有抵抗力。
