Associate Professor, Department of Prosthodontics, Istanbul Okan University Faculty of Dentistry, Istanbul, Turkey; ITI Scholar, Division of Postdoctoral and Research, National Autonomous University of Mexico, Mexico City, Mexico.
Assistant Professor, Department of Orthodontics, Istanbul Okan University Faculty of Dentistry, Istanbul, Turkey.
J Prosthet Dent. 2020 Dec;124(6):800.e1-800.e7. doi: 10.1016/j.prosdent.2020.09.004. Epub 2020 Oct 3.
The flexural strength of computer-aided design and computer-aided manufacturing (CAD-CAM) and conventional interim resin materials when they are used with a surface sealant is unclear.
The purpose of this in vitro study was to evaluate the flexural strength of different CAD-CAM polymethyl methacrylate (PMMA)-based polymers and conventional interim resin materials, autopolymerized bisacrylate composite resin and polyethyl methacrylate (PEMA) with and without a surface sealant after thermocycling.
Fourteen rectangular-shaped specimens (25×2×2 mm) were fabricated from 5 different interim resin materials, 3 different CAD-CAM PMMA-based polymers: Polident-PMMA, Telio CAD, M-PM-Disc; 2 different conventional interim resin materials, and 1 autopolymerized bisacrylate composite resin: Acyrtemp and 1 PEMA resin: Bosworth Trim according to ISO 10477:2018. Two different types of surface treatments (n=7), conventional polishing and surface sealant application, were applied to 1 surface of the specimens. Ten thousand thermocycles were applied in distilled water for all specimens (5 °C and 55 °C). A 3-point bend test was used to measure the flexural strength of specimens in a universal testing device at a 1 mm/min crosshead speed. The flexural strength data (σ) were calculated in megapascals (MPa) and analyzed by using a 2-way ANOVA. Post hoc pairwise comparisons and independent t test analysis were done (α=.05).
According to the 2-way ANOVA, material type (P<.001) significantly affected the flexural strength. Surface treatment type (P=.818) had no significant effect on flexural strength, and no significant interaction was found between material type and surface treatment type (P=.111). CAD-CAM PMMA-based polymers had significantly higher flexural strength than the conventional interim resin materials. However, no significant difference was found within groups of the same type. Also, no significant difference was found in flexural strength values between the conventional polishing and surface sealant groups within each interim resin material (P≥.162).
The flexural strength of CAD-CAM PMMA-based polymers was higher than the flexural strength of conventional bisacrylate composite resin and PEMA interim resin materials after thermocycling. The surface treatment type (conventional polishing and surface sealant application) was not found to affect the flexural strength of CAD-CAM PMMA-based polymers, conventional bisacrylate composite resin, or PEMA interim resin materials.
当使用表面密封剂时，计算机辅助设计和计算机辅助制造（CAD-CAM）和常规临时树脂材料的弯曲强度尚不清楚。
本体外研究的目的是评估不同 CAD-CAM 聚甲基丙烯酸甲酯（PMMA）基聚合物和常规临时树脂材料、自聚双丙烯酸酯复合树脂和聚甲基丙烯酸乙酯（PEMA）在热循环后使用表面密封剂前后的弯曲强度。
根据 ISO 10477:2018 标准，从 5 种不同的临时树脂材料、3 种不同的 CAD-CAM PMMA 基聚合物（Polident-PMMA、Telio CAD、M-PM-Disc）、2 种不同的常规临时树脂材料和 1 种自聚双丙烯酸酯复合树脂（Acyrtemp）和 1 种 PEMA 树脂（Bosworth Trim）中制作了 14 个矩形试件（25×2×2mm）。对试件的 1 个表面进行了两种不同类型的表面处理（n=7），常规抛光和表面密封剂应用。对所有试件施加 10000 次热循环（5°C 和 55°C），在万能试验机上以 1mm/min 的十字头速度进行三点弯曲试验，测量试件的弯曲强度。弯曲强度数据（σ）以兆帕（MPa）计算，并使用 2 因素方差分析进行分析。进行事后两两比较和独立 t 检验分析（α=0.05）。
根据 2 因素方差分析，材料类型（P<.001）显著影响弯曲强度。表面处理类型（P=.818）对弯曲强度无显著影响，且材料类型和表面处理类型之间无显著相互作用（P=.111）。CAD-CAM PMMA 基聚合物的弯曲强度明显高于常规双丙烯酸酯复合树脂和 PEMA 临时树脂材料。然而，同一类型的组内没有发现显著差异。同样，在每个临时树脂材料中，常规抛光和表面密封剂组之间的弯曲强度值也没有差异（P≥0.162）。
热循环后，CAD-CAM PMMA 基聚合物的弯曲强度高于常规双丙烯酸酯复合树脂和 PEMA 临时树脂材料。表面处理类型（常规抛光和表面密封剂应用）不影响 CAD-CAM PMMA 基聚合物、常规双丙烯酸酯复合树脂或 PEMA 临时树脂材料的弯曲强度。
