Bettero Fernanda Castelo Branco Santos, Lopes Camila de Carvalho Almança, Guerra Gabriel Júlio, Novais Veridiana Resende
Postgraduation Program in Dentistry, Faculty of Dentistry, Federal University of Uberlândia, Uberlândia, MG, Brazil.
UNA School of Dentistry, Uberlândia, MG, Brazil.
J Clin Exp Dent. 2025 Apr 1;17(4):e374-e381. doi: 10.4317/jced.62433. eCollection 2025 Apr.
Considering the importance of standardization of the pH of control solutions and its impact on the chemical composition and mechanical properties of dentin during storage over a specified period, this study aimed to analyze the pH of control solutions and how it affects the chemical composition and mechanical properties of dentin stored over a given period.
Six control solutions-coconut water, mineral water, distilled water, deionized water, artificial tears, and saline-were kept in a bacteriological incubator at 37°C, with their pH measured using a pH meter (mPA-210 from MS Tecnopon ®) for seven days: T0 (initial), T1 (2 hours), T2 (24 hours), T3 (48 hours), and T4 (7 days). In the second phase, the two solutions with the most stable pH in the first phase were selected and aligned with the critical pH of dentin (pH ≥ 6.5). Human third molars were sectioned and divided into two groups (n=13): distilled water and deionized water. The pH of the solutions, the chemical composition, and the microhardness of the dentin were evaluated by pH meter, Fourier transform infrared spectroscopy (FTIR), and Knoop microhardness (KH), respectively, at the aforementioned time points. The values were analyzed by two-way ANOVA (storage time and solution), followed by the Tukey test.
Both solutions presented pH incompatible with the dentin until T2, and the samples presented a 40% reduction in microhardness at T4. Additionally, a reduction in carbonate and an increase in amides were observed in the dentin, indicating changes in the mineral and organic phases.
It is concluded that both the solutions and the storage time negatively affect the chemical composition and microhardness of the dentin, highlighting the importance of carefully selecting the control solutions and the storage time in in vitro studies. Dentin, hardness, FTIR, pH, storage solution.
鉴于对照溶液pH值标准化的重要性及其在特定时间段储存期间对牙本质化学成分和力学性能的影响，本研究旨在分析对照溶液的pH值及其如何影响在给定时间段内储存的牙本质的化学成分和力学性能。
将六种对照溶液——椰子水、矿泉水、蒸馏水、去离子水、人工泪液和生理盐水——置于37°C的细菌培养箱中，使用pH计（MS Tecnopon®的mPA - 210）测量其pH值，为期七天：T0（初始）、T1（2小时）、T2（24小时）、T3（48小时）和T4（7天）。在第二阶段，选择第一阶段中pH最稳定的两种溶液，并使其与牙本质的临界pH值（pH≥6.5）保持一致。将人类第三磨牙切片并分为两组（n = 13）：蒸馏水组和去离子水组。在上述时间点，分别通过pH计、傅里叶变换红外光谱（FTIR）和努氏显微硬度（KH）评估溶液的pH值、牙本质的化学成分和显微硬度。通过双向方差分析（储存时间和溶液）对数值进行分析，随后进行Tukey检验。
直到T2，两种溶液的pH值均与牙本质不相容，并且样品在T4时显微硬度降低了40%。此外，在牙本质中观察到碳酸盐减少和酰胺增加，表明矿物相和有机相发生了变化。
得出的结论是，溶液和储存时间均对牙本质的化学成分和显微硬度产生负面影响，突出了在体外研究中仔细选择对照溶液和储存时间的重要性。牙本质、硬度、FTIR、pH值、储存溶液。
