Institute of Dentistry, University of Oulu and Oulu University Hospital, Oulu, Finland; Institute of Dentistry, University of Turku, Turku, Finland; The Nordic Institute of Dental Materials (NIOM), Oslo, Norway.
Dent Mater. 2013 Oct;29(10):1055-62. doi: 10.1016/j.dental.2013.07.014. Epub 2013 Aug 12.
The objective was to examine the effect of a solvent dimethyl sulfoxide (DMSO) on resin-dentin bond durability, as well as potential functional mechanisms behind the effect.
Microtensile bond strength (μTBS) was evaluated in extracted human teeth in two separate experiments. Dentin specimens were acid-etched and assigned to pre-treatment with 0.5mM (0.004%) DMSO as additional primer for 30s and to controls with water pre-treatment. Two-step etch-and-rinse adhesive (Scotchbond 1XT, 3M ESPE) was applied and resin composite build-ups were created. Specimens were immediately tested for μTBS or stored in artificial saliva for 6 and 12 months prior to testing. Additional immediate and 6-month specimens were examined for interfacial nanoleakage analysis under SEM. Matrix metalloproteinase (MMP) inhibition by DMSO was examined with gelatin zymography. Demineralized dentin disks were incubated in 100% DMSO to observe the optical clearing effect.
The use of 0.5mM DMSO had no effect on immediate bond strength or nanoleakage. In controls, μTBS decreased significantly after storage, but increased significantly in DMSO-treated group. The control group had significantly lower μTBS than DMSO-group after 6 and 12 months. DMSO also eliminated the increase in nanoleakage seen in controls. 5% and higher DMSO concentrations significantly inhibited the gelatinases. DMSO induced optical clearing effect demonstrating collagen dissociation.
DMSO as a solvent may be useful in improving the preservation of long-term dentin-adhesive bond strength. The effect may relate to dentinal enzyme inhibition or improved wetting of collagen by adhesives. The collagen dissociation required much higher DMSO concentrations than the 0.5mM DMSO used for bonding.
本研究旨在探讨溶剂二甲基亚砜（DMSO）对树脂-牙本质粘结耐久性的影响，并探讨其潜在的作用机制。
在两项独立的实验中，使用离体人牙评估微拉伸粘结强度（μTBS）。酸蚀牙本质标本，预处理组用 0.5mM（0.004%）DMSO 作为额外的底漆处理 30s，对照组用蒸馏水预处理。应用两步酸蚀-冲洗型粘结剂（Scotchbond 1XT，3M ESPE），构建树脂复合材料。即刻测试 μTBS，或在人工唾液中储存 6 个月和 12 个月后再进行测试。对额外的即刻和 6 个月标本进行 SEM 下的界面纳米渗漏分析。使用明胶酶谱法检查 DMSO 对基质金属蛋白酶（MMP）的抑制作用。将脱矿牙本质盘置于 100% DMSO 中孵育，观察光学透明效果。
使用 0.5mM DMSO 对即刻粘结强度或纳米渗漏无影响。在对照组中，储存后 μTBS 显著降低，但在 DMSO 处理组中显著增加。在 6 个月和 12 个月时，对照组的 μTBS 明显低于 DMSO 组。DMSO 还消除了对照组中观察到的纳米渗漏增加。5%及更高浓度的 DMSO 显著抑制明胶酶。DMSO 诱导光学透明效果，表明胶原解离。
作为溶剂的 DMSO 可能有助于提高长期牙本质-粘结剂粘结强度的保存。其作用可能与牙本质酶抑制或提高粘结剂对胶原的润湿性有关。胶原解离所需的 DMSO 浓度远高于用于粘结的 0.5mM。
