Department of Restorative Dentistry, Dental School, University of São Paulo, São Paulo, Brazil 05508-900.
Microsc Res Tech. 2011 Dec;74(12):1083-7. doi: 10.1002/jemt.20998. Epub 2011 Apr 29.
This study evaluated and compared in vitro the morphology and mineral composition of dental enamel after erosive challenge in gastric juice and orange juice. Human enamel specimens were submitted to erosive challenge using gastric juice (from endoscopy exam) (n = 10), and orange juice (commercially-available) (n = 10), as follows: 5 min in 3 mL of demineralization solution, rinse with distilled water, and store in artificial saliva for 3 h. This cycle was repeated four times a day for 14 days. Calcium (Ca) loss after acid exposure was determined by atomic emission spectroscopy. The presence of carbonate (CO) and phosphate (PO) in the specimens was evaluated before and after the erosive challenge by FT-Raman spectroscopy. Data were tested using t-tests (P < 0.05). Morphology of enamel was observed in scanning electron microscopy (SEM). The mean loss of Ca was: 12.74 ± 3.33 mg/L Ca (gastric juice) and 7.07 ± 1.44 mg/L Ca (orange juice). The analysis by atomic emission spectroscopy showed statistically significant difference between erosive potential of juices (P = 0.0003). FT-Raman spectroscopy found no statistically significant difference in the ratio CO/PO after the erosive challenge. The CO/PO ratios values before and after the challenge were: 0.16/0.17 (gastric juice) (P = 0.37) and 0.18/0.14 (orange juice) (P = 0.16). Qualitative analysis by SEM showed intense alterations of enamel surface. The gastric juice caused more changes in morphology and mineral composition of dental enamel than orange juice. The atomic emission spectroscopy showed to be more suitable to analyze small mineral loss after erosive challenge than FT-Raman.
这项研究评估并比较了胃蛋白酶和橙汁侵蚀性挑战后牙釉质的形态和矿物质组成。人类牙釉质标本分别用胃蛋白酶（内窥镜检查）（n = 10）和橙汁（市售）（n = 10）进行侵蚀性挑战：在 3 mL脱矿溶液中浸泡 5 分钟，用蒸馏水冲洗，然后在人工唾液中储存 3 小时。每天重复此循环四次，持续 14 天。酸暴露后钙（Ca）损失通过原子发射光谱法确定。通过傅里叶变换拉曼光谱法（FT-Raman）在侵蚀性挑战前后评估标本中碳酸盐（CO）和磷酸盐（PO）的存在。使用 t 检验（P < 0.05）检验数据。牙釉质的形态用扫描电子显微镜（SEM）观察。Ca 的平均损失为：胃蛋白酶中的 12.74 ± 3.33 mg/L Ca 和橙汁中的 7.07 ± 1.44 mg/L Ca。原子发射光谱分析显示果汁的侵蚀潜力有统计学差异（P = 0.0003）。FT-Raman 光谱分析显示侵蚀性挑战后 CO/PO 比值无统计学差异。挑战前后 CO/PO 比值分别为：胃蛋白酶中的 0.16/0.17（P = 0.37）和橙汁中的 0.18/0.14（P = 0.16）。SEM 的定性分析显示牙釉质表面发生了强烈的变化。胃蛋白酶比橙汁更能改变牙釉质的形态和矿物质组成。原子发射光谱法比傅里叶变换拉曼光谱法更适合分析侵蚀性挑战后的小量矿物质损失。
