Par Matej, Gubler Andrea, Attin Thomas, Tarle Zrinka, Tarle Andro, Tauböck Tobias T
Department of Endodontics and Restorative Dentistry, School of Dental Medicine, University of Zagreb, Gunduliceva 5, 10000 Zagreb, Croatia.
Department of Conservative and Preventive Dentistry, Center for Dental Medicine, University of Zurich, Plattenstrasse 11, 8032 Zurich, Switzerland.
Biomedicines. 2021 Nov 4;9(11):1616. doi: 10.3390/biomedicines9111616.
The purpose of this in vitro study was to investigate whether different types of experimental and commercial restorative dental materials can protect dentin against acid-induced softening. Experimental composites were prepared with a photocurable mixture of methacrylates and two types of bioactive glass (45S5 and a customized low-Na F-containing formulation). Human dentin samples were prepared from mid-coronal tooth slices and immersed in lactic acid solution (pH = 4.0) at 5 mm from set specimens of restorative material. After 4, 8, 12, 16, 20, 24, 28, and 32 days, surface microhardness of dentin samples and pH of the immersion solution were measured, followed by replenishing of the immersion medium. Microstructural analysis was performed using scanning electron microscopy. The protective effect of restorative materials was determined as dentin microhardness remaining statistically similar to initial values for a certain number of acid additions. Scanning electron microscopy showed a gradual widening of dentinal tubules and proved less discriminatory than microhardness measurements. To produce a protective effect on dentin, 20 wt% of low-Na F-containing bioactive glass was needed, whereas 10 wt% of bioactive glass 45S5 was sufficient to protect dentin against acid-induced demineralization. The anti-demineralizing protective effect of experimental and commercial restoratives on dentin was of shorter duration than measured for enamel in a previous study using the same experimental approach.
本体外研究的目的是调查不同类型的实验性和商业性牙科修复材料是否能保护牙本质免受酸诱导软化的影响。实验性复合材料由甲基丙烯酸酯与两种生物活性玻璃（45S5和定制的低钠含氟配方）的光固化混合物制备而成。从牙冠中部切片制备人牙本质样本，并将其浸入距修复材料固化样本5毫米处的乳酸溶液（pH = 4.0）中。在4、8、12、16、20、24、28和32天后，测量牙本质样本的表面显微硬度和浸泡溶液的pH值，然后补充浸泡介质。使用扫描电子显微镜进行微观结构分析。修复材料的保护作用被确定为在一定数量的酸添加后，牙本质显微硬度在统计学上与初始值保持相似。扫描电子显微镜显示牙本质小管逐渐变宽，且证明其区分能力不如显微硬度测量。为了对牙本质产生保护作用，需要20 wt%的低钠含氟生物活性玻璃，而10 wt%的生物活性玻璃45S5足以保护牙本质免受酸诱导的脱矿。使用相同实验方法，实验性和商业性修复材料对牙本质的抗脱矿保护作用持续时间比先前研究中对牙釉质测量的持续时间短。
