Arcís Raul W, López-Macipe Anabel, Toledano Manuel, Osorio Estrella, Rodríguez-Clemente Rafael, Murtra Jaime, Fanovich Maria A, Pascual Concepción Domingo
Institut de Ciència de Materials de Barcelona, Campus de la UAB, Bellaterra, Spain.
Dent Mater. 2002 Jan;18(1):49-57. doi: 10.1016/s0109-5641(01)00019-7.
The purpose of this study was to measure and analyze the mechanical properties of several composite materials designed for dental restoration.
The materials were composed of a visible light-curing monomer mixture (either Bis-GMA+TEGDMA or Bis-GMA+HEMA) as a matrix and hydroxyapatite (either microscopic or nanoscopic particles) as a reinforcing filler. The surface of the hydroxyapatite particles was modified by using a coupling agent (citric, malic, acrylic or methacrylic acid). Five specimens of 14 different composites were prepared for each mechanical test: flexural strength, Young's modulus and Vickers hardness. Mean values and standard deviations were calculated, and ANOVA and Student Newman Keuls multiple comparison tests were applied (P < 0.05).
The addition of 50-60 wt% of hydroxyapatite particles to the unfilled monomer mixtures led to the increase of both Young's modulus and surface hardness of the material, while the flexural strength decreased. In general, when microscopic instead of nanoscopic hydroxyapatite was used as a reinforcing filler, mechanical properties were favored. The mechanical properties were also improved by adding citric, acrylic or methacrylic acid as a coupling agent.
An adequate surface modification of the hydroxyapatite particles conferred enhanced mechanical properties to the final dental composite. Microscopic-hydroxyapatite particles are preferred to nanoscopic ones.
本研究的目的是测量和分析几种用于牙齿修复的复合材料的力学性能。
这些材料由作为基质的可见光固化单体混合物（双酚A缩水甘油醚+三乙二醇二甲基丙烯酸酯或双酚A缩水甘油醚+甲基丙烯酸羟乙酯）和作为增强填料的羟基磷灰石（微观或纳米颗粒）组成。通过使用偶联剂（柠檬酸、苹果酸、丙烯酸或甲基丙烯酸）对羟基磷灰石颗粒表面进行改性。为每项力学测试（弯曲强度、杨氏模量和维氏硬度）制备了14种不同复合材料的5个试样。计算平均值和标准差，并应用方差分析和学生-纽曼-库尔斯多重比较检验（P<0.05）。
向未填充的单体混合物中添加50-60 wt%的羟基磷灰石颗粒会导致材料的杨氏模量和表面硬度增加，而弯曲强度降低。一般来说，如果使用微观而非纳米级的羟基磷灰石作为增强填料，则有利于力学性能。添加柠檬酸、丙烯酸或甲基丙烯酸作为偶联剂也可改善力学性能。
对羟基磷灰石颗粒进行适当的表面改性可赋予最终牙科复合材料增强的力学性能。微观羟基磷灰石颗粒比纳米级的更可取。
