Clinics of Dentistry for Disabled, Tohoku University Hospital, Tohoku University.
Division of Dental Biomaterials, Tohoku University Graduate School of Dentistry.
J Oral Sci. 2022 Jul 1;64(3):242-246. doi: 10.2334/josnusd.22-0012. Epub 2022 Jun 10.
Moisture exclusion while treating dental caries can be challenging, and the glass ionomer cements (GICs) used for these procedures are susceptible to water. Few studies have examined the effects of the powder/liquid ratio (PLR) on the physical properties of GICs exposed to water. In this study, the hardness and thickness of the water-susceptible surface layer of three GICs were evaluated.
Three conventional GICs were mixed in increasing PLRs, and hardness over time was measured under conditions of no water exposure, distilled water exposure, and saliva exposure. Furthermore, the thickness of the water-susceptible layer for each GIC was determined.
A water-susceptible layer of approximately 250 μm was evident for all GICs, and the thickness decreased with increasing PLR. GIC hardness increased with increasing PLR in conditions without water for all GIC types. Furthermore, the removal of the water-susceptible layer restored the physical properties of each GIC.
Overall, the results indicate that conventional GIC restoration with the removal of the water-susceptible surface layer is a feasible strategy for treating dental caries in individuals for whom exclusion of moisture can be difficult.
在治疗龋齿时，防止水分进入是一项挑战，而用于这些治疗的玻璃离子水门汀（GIC）容易受到水分的影响。很少有研究探讨过粉液比（PLR）对暴露于水分的 GIC 物理性能的影响。本研究评估了三种 GIC 暴露于水分时的表面易感性硬度和厚度。
将三种传统的 GIC 按比例混合，并在不暴露于水、蒸馏水和唾液的情况下，随时间测量硬度。此外，还确定了每种 GIC 的易感性水层的厚度。
所有 GIC 都有大约 250μm 的易感性水层，厚度随 PLR 的增加而减少。在所有 GIC 类型中，在没有水的情况下，PLR 越高，GIC 硬度越高。此外，去除易感性水层可恢复每种 GIC 的物理性能。
总的来说，结果表明，对于那些难以防止水分进入的患者，通过去除易感性表面层来进行传统 GIC 修复是一种可行的治疗龋齿的策略。
