Professor, Graduate Prosthodontics, Specialty in Aesthetic, Cosmetic, Restorative, and Implant Dentistry, Faculty of Stomatology, Autonomous University of San Luis Potosi, San Luis Potosi, Mexico.
Graduate student, Graduate Prosthodontics, Specialty in Aesthetic, Cosmetic, Restorative, and Implant Dentistry, Faculty of Stomatology, Autonomous University of San Luis Potosi, San Luis Potosi, Mexico.
J Prosthet Dent. 2023 Aug;130(2):256.e1-256.e12. doi: 10.1016/j.prosdent.2023.05.009. Epub 2023 Jun 23.
Lack of conversion of resin cements for luting glass fiber posts in deeper levels of the root canal may compromise clinical performance.
The purpose of this in vitro study was to evaluate the effect of the degree of conversion on the surface properties of dual-polymerized resin cements used for cemented glass fiber posts according to the root level.
Fifty maxillary central incisor teeth were endodontically treated, and glass fiber posts were cemented using the following systems: self-adhesive dual-polymerized resin luting cement (RelyX U200) and dual-polymerizing flowable core and a post luting system (Rebilda DC) with a self-etching adhesive (Futurabond DC). The degree of conversion was determined via attenuated total reflectance and Fourier transform infrared spectroscopy, and surface microhardness and cement film thickness were measured. The intraradicular fit was evaluated with microscopy. All tests were performed in the coronal, middle, and apical third of the root canal. Statistical analysis was done with ANOVA and the multiple comparison Tukey test (α=.05).
The degree of conversion was higher in the coronal third using Rebilda DC (65.3 ±4.8%) than RelyX U200 (38.7 ±5.3%) (P<.05); on both resin cements, these values decreased from the coronal to the apical third (30.9 ±3.7%, 61.9 ±8.7%, respectively). The cement film thickness was higher for RelyX U200 in the 3 thirds than for Rebilda DC; significant differences (P<.05) were recorded in both cementing systems in the coronal and apical thirds. In the middle third, no significant differences were observed (P>.05). The mean surface microhardness values increased in the coronal thirds and decreased with increasing root canal depth. The marginal seal in the coronal thirds and the intraradicular fit in the middle thirds showed closer adaptation; however, some tags were observed in the interface resin cement and radicular dentin. Gap and tag formations were observed in the apical third.
Depending on the root canal third, the surface properties of dual-polymerized resin cements are influenced by the degree of conversion.
根管内较深部位的树脂水门汀的转化率低，可能会影响临床效果。
本体外研究的目的是根据根管水平评估转化率对用于粘结玻璃纤维桩的双固化树脂水门汀表面性能的影响。
50 颗上颌中切牙进行根管治疗，使用以下系统粘结玻璃纤维桩：自粘结双固化树脂水门汀（RelyX U200）和双固化流动核与桩粘结系统（Rebilda DC）配合自酸蚀粘结剂（Futurabond DC）。通过衰减全反射和傅里叶变换红外光谱法测定转化率，测量表面显微硬度和粘结层厚度。用显微镜评估根管内的适合性。所有测试均在根管的冠、中、根尖三分之一进行。采用方差分析和多重比较 Tukey 检验（α=.05）进行统计分析。
Rebilda DC 在根管冠三分之一的转化率高于 RelyX U200（65.3±4.8%比 38.7±5.3%）（P<.05）；在两种树脂水门汀中，这些值从冠向根尖三分之一逐渐降低（分别为 30.9±3.7%、61.9±8.7%）。RelyX U200 在 3 个三分之一的粘结层厚度均高于 Rebilda DC；在两种粘结系统的冠、根尖三分之一均有显著差异（P<.05）。在中间三分之一，未观察到显著差异（P>.05）。表面显微硬度值在根管冠三分之一处增加，随根管深度增加而降低。冠三分之一的边缘密封和中三分之一的根管内适合性显示出更紧密的适应性；然而，在粘结剂和根管牙本质的界面处观察到一些标签。在根尖三分之一处观察到间隙和标签形成。
根据根管的三分之一，双固化树脂水门汀的表面性能受转化率的影响。
