Unité de Recherches Biomatériaux Innovants et Interfaces (URB2I-EA4462), Faculté de chirurgie dentaire, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.
Dent Mater. 2013 May;29(5):535-41. doi: 10.1016/j.dental.2013.02.006. Epub 2013 Mar 21.
The aim of this study was to use high-pressure high-temperature (HP/HT) polymerization to produce urethane dimethacrylate (UDMA)-triethylene glycol dimethacrylate (TEGDMA) based resin composite blocks (RCB) suitable for dental computer-aided design/manufacture (CAD/CAM) applications and to compare their physical/mechanical properties to those of a commercial dental RCB. The null hypotheses tested were: (1) there are no differences in the physical/mechanical properties between HP/HT polymerized UDMA-TEGDMA RCB and a commercial RCB; (2) volume fraction filler (Vf) does not affect the physical/mechanical properties of HP/HT polymerized RCB.
Four UDMA-based experimental RCB were manufactured under HP/HT conditions. A RCB manufactured under the same HP/HT conditions from a commercial resin composite (Z100) and its commercial counterpart CAD/CAM RCB (Paradigm MZ100) were used as controls. Flexural strength (σf), fracture toughness (KIC), and hardness were determined. The results were analyzed using one-way ANOVA, Scheffé multiple means comparisons (α=0.05), and Weibull statistics (for σf). Scanning electron microscopy was used to characterize fractured surfaces.
All HP/HT polymerized RCB had superior σf, KIC, and Weibull modulus compared to the commercial dental RCB. The experimental RCB had similar or superior properties compared to HP/HT polymerized Z100 RCB. Fewer and smaller porosities (not quantified) were apparent in HP/HT polymerized RCB. The experimental RCB that contained 65% Vf showed higher porosity, suggesting practical difficulties in filler incorporation beyond a certain Vf.
The results of this study suggested that RCB suitable for dental CAD/CAM applications could be obtained by HP/HT polymerization of resin composites based on pure UDMA.
本研究旨在使用高压高温（HP/HT）聚合来生产适用于牙科计算机辅助设计/制造（CAD/CAM）应用的基于二甲基丙烯酸酯（UDMA）-三乙二醇二甲基丙烯酸酯（TEGDMA）的树脂复合块（RCB），并比较其物理/机械性能与商业牙科 RCB 的性能。检验的零假设为：（1）HP/HT 聚合的 UDMA-TEGDMA RCB 与商业 RCB 的物理/机械性能无差异；（2）体积分数填充物（Vf）不会影响 HP/HT 聚合的 RCB 的物理/机械性能。
在 HP/HT 条件下制造了四种基于 UDMA 的实验性 RCB。使用在相同 HP/HT 条件下制造的商业树脂复合材料（Z100）和其商业对应 CAD/CAM RCB（Paradigm MZ100）的 RCB 作为对照。测定弯曲强度（σf）、断裂韧性（KIC）和硬度。使用单因素方差分析、谢菲多重均值比较（α=0.05）和威布尔统计（用于σf）分析结果。使用扫描电子显微镜对断裂表面进行了特征描述。
所有 HP/HT 聚合的 RCB 的σf、KIC 和威布尔模数均优于商业牙科 RCB。实验性 RCB 的性能与 HP/HT 聚合的 Z100 RCB 相似或更优。HP/HT 聚合的 RCB 中出现的孔隙较少且较小（未定量）。含有 65%Vf 的实验性 RCB 显示出更高的孔隙率，表明在一定 Vf 以上填充料的加入存在实际困难。
本研究结果表明，通过基于纯 UDMA 的树脂复合材料的 HP/HT 聚合，可以获得适用于牙科 CAD/CAM 应用的 RCB。
