The aim of this study was to evaluate the remineralizing properties of ion-releasing restorative materials on pH cycling-induced carious dentin. Fifty sound molars were freshly extracted. The occlusal surfaces were abraded using water-cooled sandpaper (800 grit). The residual crowns were embedded in self-cured acrylic resin with the flat dentin surface exposed. A mesio-distal trench was created using a calibrated 0.5 mm deep occlusal reduction burr, and artificial dentin caries were generated by pH cycling. Then, teeth were randomly assigned to five groups according to the ion-releasing material used. For each sample, micro-CT acquisitions were performed at various intervals. Remineralization was assessed by mean gray value (MGV) measurements after registration and segmentation of the region of interest with 3D Slicer software. One-way repeated-measures ANOVA followed by Tukey’s post hoc test was used to investigate the difference in MGVs among the various groups. Only Cention Forte showed significantly increased MGVs after 4 weeks compared to demineralized dentin. MGVs were higher, but not significantly, after placement of the restorative materials, including in the resin composite control group. These results can be explained by the radiopacity of the materials. Cention Forte, the material with the highest radiopacity, showed a significant increase in the MGVs of artificially carious dentin after 4 weeks. However, the study of dentin remineralization by micro-CT could be impacted by the radiopacity of the restorative materials used. The relevance of this examination for the study of dentinal remineralization should be investigated.

中文翻译：

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人工脱矿牙本质的各种离子释放材料的体外再矿化：显微 CT 研究

本研究的目的是评估离子释放修复材料对 pH 循环引起的龋齿牙本质的再矿化特性。刚拔出五十颗完好的臼齿。使用水冷砂纸（800 目）打磨咬合面。将剩余牙冠嵌入自固化丙烯酸树脂中，露出平坦的牙本质表面。使用校准的 0.5 毫米深的咬合减少毛刺创建近远中沟槽，并通过 pH 循环产生人工牙本质龋齿。然后，根据所使用的离子释放材料，将牙齿随机分为五组。对于每个样品，以不同的时间间隔进行显微 CT 采集。使用 3D Slicer 软件对感兴趣区域进行配准和分割后，通过平均灰度值 (MGV) 测量来评估再矿化情况。使用单向重复测量方差分析和 Tukey 事后检验来研究各组之间 MGV 的差异。与脱矿牙本质相比，仅 Cention Forte 在 4 周后表现出 MGV 显着增加。放置修复材料后（包括树脂复合材料对照组），MGV 较高，但并不显着。这些结果可以用材料的射线不透性来解释。Cention Forte 是射线不透性最高的材料，4 周后人工龋牙本质的 MGV 显着增加。然而，通过显微 CT 进行的牙本质再矿化研究可能会受到所用修复材料的射线不透性的影响。应调查该检查与牙本质再矿化研究的相关性。