已经声称,碱土修复材料可以中和由致龋细菌从释放的氢离子产生的酸,并且能够经由钙和氟离子再矿化。然而,没有证据支持这一说法。因此,这项研究的目的是研究碱石修复材料对变异链球菌生物膜的pH值和牙本质硬度的影响。
变形链球菌生物膜在Filtek™Z350上形成(FZ,树脂复合材料)和Cantion®N(CN,碱土修复材料)及其在24小时后确定的pH值。氢氧化物,氟化物,并在6小时测定从材料中释放的钙离子,1、3、7、14和28天。牙本质标本是从14个人类磨牙中制备的,并分为四个象限。象限1是一个良好的牙本质控制,象限2-4被化学去矿化,以及分别放置在象限2和4的表面上的FZ和CN的圆柱体。在距咬合面20、40和60µm的深度处测量象限1和3的显微硬度,30天后,象限2和4也是如此。独立t检验,Mann-Whitney-U,和重复测量方差分析用于数据分析。
CN上生物膜的pH(4.45)明显高于FZ上的pH(4.06)(p<0.05)。从CN释放的所有离子的量显著高于从FZ释放的所有离子的量。CN下脱矿牙本质的硬度明显高于所有深度的脱矿牙本质,高于FZ下20和40µm的脱矿质牙本质。
CN释放的氢氧化物,氟化物,和钙离子,这与提高生物膜的pH值和脱矿质牙本质的硬度有关。所有结果表明,CN具有降低继发性龋齿发生率的潜力。
BACKGROUND: It has been claimed that an alkasite restorative material can neutralize acids produced by cariogenic bacteria from released hydrogen ions and enable to remineralization via calcium and fluoride ions. However, there is no evidence to support this assertion. Therefore, the aims of this
study were to investigate the effect of the alkasite restorative material on the pH of Streptococcus mutans biofilm and dentin hardness.
METHODS: Streptococcus mutans biofilms were formed on Filtek™ Z350 (FZ, a resin composite) and Cention® N (CN, the alkasite restorative material) and their pH determined after 24 h. Hydroxide, fluoride, and calcium-ions released from the materials were determined at 6 h, 1, 3, 7, 14, and 28 days. Dentin specimens were prepared from 14 human molars and divided into four quadrants. Quadrant 1 was a sound dentin control, quadrants 2-4 were chemically demineralized, and a cylinder of FZ and CN placed on the surfaces of quadrants 2 and 4, respectively. The microhardness of quadrants 1 and 3 were measured at depths of 20, 40, and 60 µm from the occlusal surface, and similarly of quadrants 2 and 4, after 30 days. Independent t-test, Mann-Whitney-U, and repeated-measure-ANOVA were used for data analysis.
RESULTS: The pH of biofilm on CN (4.45) was significantly higher (p < 0.05) than that on FZ (4.06). The quantity of all ions released from CN was significantly higher than from FZ. The hardness of demineralized dentin under CN was significantly higher than that of demineralized dentin at all depths, and higher than that of demineralized dentin under FZ at 20 and 40 µm.
CONCLUSIONS: CN released hydroxide, fluoride, and calcium ions, which was associated with raising the biofilm pH and the hardness of demineralized dentin. All results indicated that CN had the potential to reduce the incidence of secondary caries.