Ruiz Santiago, Díaz-Soriano Ana, Gallo Walter, Perez-Vargas Fernando, Munive-Degregori Arnaldo, Mayta-Tovalino Frank
Department of Master in Stomatology, Faculty of Dentistry, Universidad Nacional Mayor de San Marcos, Lima-Peru.
Department of Preventive and Social Stomatology, Faculty of Dentistry, Universidad Nacional Mayor de San Marcos, Lima-Peru.
J Int Soc Prev Community Dent. 2020 Aug 6;10(4):473-480. doi: 10.4103/jispcd.JISPCD_158_20. eCollection 2020 Jul-Aug.
The objective of this study was to assess the structural changes in translucency and opacity of tooth enamel following a direct demineralization process.
This experimental study evaluated 45 thirds (cervical, middle, and occlusal) of the tooth enamel surface of premolar teeth extracted from young adults divided into three groups of 15 specimens each: Group 1 (solution based on calcium, phosphorus, and fluorine), Group 2 (orthophosphoric acid 37%), and control group (distilled water). All underwent optical macroscopic examination with ×3 magnification to determine the initial translucency according to the variation of the medium in their intercrystalline spaces, and Thylstrup and Fejerskov Index was used. The experimental groups were then subjected to an artificial caries process during which the specimens were placed in an inorganic and organic solution of calcium, phosphorus, and fluorine at 37°C for 90 days with the acidic solution at pH 5 and the neutral solution at pH 7. The control specimens were placed in distilled water. Finally, all the specimens were assessed by polarization microscopy.
In relation to the occlusal third, the highest proportion in Groups 1 and 2 was in Grades 2 and 3 (80%). A significant association was only observed between the experimental groups in the degree of translucency in the occlusal third ( = 0.002), whereas no association was found in relation to the degree of opacity in the middle and cervical thirds in either study group ( > 0.05).
The resistance of enamel hydroxyapatite crystals increases from occlusal to cervical due to the greater presence of aprismatic enamel in the cervical horizontal third.
本研究的目的是评估直接脱矿过程后牙釉质透明度和不透明度的结构变化。
本实验研究评估了从年轻成年人拔除的前磨牙牙釉质表面的45个牙面（颈部、中部和咬合面），分为三组，每组15个标本：第1组（基于钙、磷和氟的溶液），第2组（37%正磷酸），以及对照组（蒸馏水）。所有标本均在×3放大倍数下进行光学宏观检查，根据其晶间空间中介质的变化确定初始透明度，并使用Thylstrup和Fejerskov指数。然后对实验组进行人工龋过程，在此过程中，将标本置于37°C的钙、磷和氟的无机和有机溶液中90天，酸性溶液pH值为5，中性溶液pH值为7。对照标本置于蒸馏水中。最后，所有标本均通过偏振显微镜进行评估。
关于咬合面牙面，第1组和第2组中最高比例处于2级和3级（80%）。仅在实验组的咬合面牙面透明度程度之间观察到显著关联（ = 0.002），而在任何研究组的中部和颈部牙面不透明度程度方面均未发现关联（ > 0.05）。
由于颈部水平牙面中无棱柱釉质的存在更多，牙釉质羟基磷灰石晶体的抗性从咬合面向颈部增加。
