Mehtälä P, Pashley D H, Tjäderhane L
Research Unit of Oral Health Sciences, and Medical Research Center Oulu (MRC Oulu), Oulu University Hospital and University of Oulu, Oulu, Finland.
The Dental College of Georgia, Augusta University, Augusta, GA, USA.
Dent Mater. 2017 Aug;33(8):915-922. doi: 10.1016/j.dental.2017.04.018. Epub 2017 Jun 10.
Infiltration of adhesive on dentin matrix depends on interaction of surface and adhesive. Interaction depends on dentin wettability, which can be enhanced either by increasing dentin surface energy or lowering the surface energy of adhesive. The objective was to examine the effect of dimethyl sulfoxide (DMSO) on demineralized dentin wettability and dentin organic matrix expansion.
Acid-etched human dentin was used for sessile drop contact angle measurement to test surface wetting on 1-5% DMSO-treated demineralized dentin surface, and linear variable differential transformer (LVDT) to measure expansion/shrinkage of dentinal matrix. DMSO-water binary liquids were examined for surface tension changes through concentrations from 0 to 100% DMSO. Kruskal-Wallis and Mann-Whitney tests were used to test the differences in dentin wettability, expansion and shrinkage, and Spearman test to test the correlation between DMSO concentration and water surface tension. The level of significance was p<0.05.
Pretreatment with 1-5% DMSO caused statistically significant concentration-dependent increase in wetting: the immediate contact angles decreased by 11.8% and 46.6% and 60s contact angles by 9.5% and 47.4% with 1% and 5% DMSO, respectively. DMSO-water mixtures concentration-dependently expanded demineralized dentin samples less than pure water, except with high (≥80%) DMSO concentrations which expanded demineralized dentin more than water. Drying times of LVDT samples increased significantly with the use of DMSO.
Increased dentin wettability may explain the previously demonstrated increase in adhesive penetration with DMSO-treated dentin, and together with the expansion of collagen matrix after drying may also explain previously observed increase in dentin adhesive bonding.
粘结剂在牙本质基质上的渗透取决于表面与粘结剂之间的相互作用。这种相互作用取决于牙本质的润湿性，可通过提高牙本质表面能或降低粘结剂表面能来增强。本研究旨在探讨二甲基亚砜（DMSO）对脱矿牙本质润湿性及牙本质有机基质膨胀的影响。
采用酸蚀人牙本质进行静滴接触角测量，以测试1 - 5%DMSO处理的脱矿牙本质表面的润湿性，并用线性可变差动变压器（LVDT）测量牙本质基质的膨胀/收缩情况。研究了DMSO - 水二元液体在0至100%DMSO浓度范围内的表面张力变化。采用Kruskal - Wallis和Mann - Whitney检验来测试牙本质润湿性、膨胀和收缩的差异，并用Spearman检验来测试DMSO浓度与水表面张力之间的相关性。显著性水平为p<0.05。
用1 - 5%DMSO预处理导致润湿性呈统计学显著的浓度依赖性增加：1%DMSO和5%DMSO处理后，即刻接触角分别降低了11.8%和46.6%，60秒接触角分别降低了9.5%和47.4%。除高浓度（≥80%）DMSO使脱矿牙本质膨胀超过水外，DMSO - 水混合物使脱矿牙本质样品的膨胀呈浓度依赖性小于纯水。使用DMSO后，LVDT样品的干燥时间显著增加。
牙本质润湿性增加可能解释了先前证明的DMSO处理的牙本质中粘结剂渗透增加的现象，并且与干燥后胶原基质的膨胀一起也可能解释了先前观察到的牙本质粘结强度增加的现象。
