Zhi Li, Bortolotto Tissiana, Krejci Ivo
Assistant, Department of Stomatology, Beijing University, People's Hospital, Beijing, China.
Research Section Head, Division of Cariology and Endodontology, School of Dental Medicine, University of Geneva, Geneva, Switzerland.
J Prosthet Dent. 2016 Feb;115(2):199-202. doi: 10.1016/j.prosdent.2015.07.011. Epub 2015 Oct 14.
Composite resin is a promising option in computer-aided design and computer-aided manufacturing (CAD/CAM) dentistry; however, the wear resistance of composite resin remains a primary concern.
The purpose of this in vitro study was to evaluate the wear resistance of 5 CAD/CAM materials (n=10), consisting of 4 composite resins (3M Lava Ultimate, Kerr experimental composite resin material, Vita Enamic, 3M Paradigm MZ100) and 1 ceramic (Vita Mark II) in contact with natural human enamel cusps.
Specimens were loaded into a computer-controlled mastication simulator and subjected to 200000 mechanical cycles (49 N) against natural human enamel simultaneously with 500 thermal cycles (5°C to 50°C to 5°C). The wear resistance was analyzed by measuring the vertical substance loss (the maximum depth of the worn area) in the contact point area of the specimen. The worn surfaces were observed by scanning electron microscopy to determine the wear patterns.
Vita Mark II exhibited the best wear resistance among the tested materials, followed by 3M Lava Ultimate, Vita Enamic, and 3M Paradigm MZ100. The Kerr experimental material exhibited the lowest wear resistance, yet its results were not significantly different from those of the 3 other composite resin blocks (P>.05).
Within the limitations of this in vitro study, the wear resistance of composite resin blocks in contact with enamel cusps was significantly lower than that of a ceramic block.
复合树脂是计算机辅助设计与计算机辅助制造（CAD/CAM）牙科领域中一种很有前景的材料；然而，复合树脂的耐磨性仍然是一个主要问题。
本体外研究的目的是评估5种CAD/CAM材料（n = 10）的耐磨性，这些材料包括4种复合树脂（3M Lava Ultimate、Kerr实验性复合树脂材料、Vita Enamic、3M Paradigm MZ100）和1种陶瓷（Vita Mark II）与天然人牙釉质牙尖接触时的情况。
将标本加载到计算机控制的咀嚼模拟器中，在49 N的力下与天然人牙釉质同时进行200000次机械循环，并进行500次热循环（5°C至50°C再至5°C）。通过测量标本接触点区域的垂直物质损失（磨损区域的最大深度）来分析耐磨性。通过扫描电子显微镜观察磨损表面以确定磨损模式。
在测试材料中，Vita Mark II表现出最佳的耐磨性，其次是3M Lava Ultimate、Vita Enamic和3M Paradigm MZ100。Kerr实验材料表现出最低的耐磨性，但其结果与其他3种复合树脂块的结果无显著差异（P>0.05）。
在本体外研究的局限性内，与牙釉质牙尖接触的复合树脂块的耐磨性显著低于陶瓷块。
