Evaluation of methacrylic resin-modified calcium silicate cements for pulpal healing using an experimental pulpitis...

Recently, vital pulp treatment (VPT), including direct pulp capping, which preserves pulp vitality and extends the functional lifespan of teeth, has garnered significant attention. The purpose of this study was to evaluate the performance of calcium silicate cement, the gold standard for VPT, alongside hydraulic calcium silicate cement (Pro-MTA), a material with extensive evidence of effectiveness, Bis-GMA resin-modified calcium silicate cement (TH), and a newly developed material, methacrylate resin-modified calcium silicate cement (RM-MTA), in a model of pulpitis induced by caries progression. Additionally, the calcium ion (Ca²⁺) release capacity of these materials and their comprehensive effects on pulpal wound healing were assessed using RNA sequencing (RNA-seq). In both sound pulp models and caries-induced pulpitis models, RM-MTA and Pro-MTA exhibited similar performances. Unlike TH, they induced significant tertiary dentin formation within the dental pulp beneath the material, without any residual inflammatory cells. Inflammation was specifically assessed with a focus on M1/M2 macrophages. While the timing of Ca²⁺ ion release differed among the materials, the total amount released was comparable, although the release of calcium ions (Ca²⁺) from TH was significantly lower compared to that observed for the above materials. Moreover, comprehensive genetic analysis revealed that the expression of cell proliferation-related genes was selectively reduced in TH, suggesting that differences in resin composition may account for these variations in behavior. These findings suggest that RM-MTA induces tertiary dentin and demonstrates biocompatibility comparable to that of Pro-MTA. This makes it suitable for the treatment of both sound and mildly inflamed pulp tissues. Additionally, its resin properties are expected to enhance both mechanical performance and clinical handling.