Kawaguchi Tomohiro, Lassila Lippo V J, Sasaki Hirono, Takahashi Yutaka, Vallittu Pekka K
Department of Biomaterials Science, Institute of Dentistry, University of Turku, BioCity Turku Biomaterials Research Program, Turku, Finland; Division of Removable Prosthodontics, Department of Oral Rehabilitation, Fukuoka Dental College, Fukuoka, Japan.
Department of Biomaterials Science, Institute of Dentistry, University of Turku, BioCity Turku Biomaterials Research Program, Turku, Finland.
J Mech Behav Biomed Mater. 2014 Nov;39:73-8. doi: 10.1016/j.jmbbm.2014.07.012. Epub 2014 Jul 24.
The aim of this research was to investigate the effects of heat treatment of polymethyl methacrylate powder on mechanical properties of denture base resin.
PMMA powder was applied after heat treatment at 100°C for 2h (code: HT100) or 130°C for 2h (code: HT130). The test specimens were fabricated from autopolymerizing resin to investigate the flexural properties of denture base resin cross-linked with methacrylated dendrimer, the surface microhardness of PMMA beads, and the thickness of the swollen layer of PMMA beads. The specimens were autopolymerized, and all specimens were stored in 37°C water for 24h. Half of the specimens were immersed in 37°C water for an additional 6 months (water storage period: 24h and 6 months). The flexural strength and flexural modulus (n=10/group) were measured with a three point bending test. Statistical analysis was performed using ANOVA and the Newman-Keuls test at a significance level of 0.05.
Heat treatment and the water storage period had a significant effect on flexural strength. The flexural strength of HT130 showed significantly higher values than in other groups. The surface microhardness of PMMA beads of HT130 showed a significantly greater microhardness than other groups. The thickness of a swollen layer of PMMA beads of HT100 and HT130 was significantly decreased.
The flexural strength and the surface microhardness were increased after heat treatment at 130°C. The thickness of a swollen layer of PMMA beads was decreased after heat treatment.
本研究旨在探讨聚甲基丙烯酸甲酯粉末热处理对义齿基托树脂力学性能的影响。
聚甲基丙烯酸甲酯粉末在100°C热处理2小时（编号：HT100）或130°C热处理2小时（编号：HT130）后使用。用自凝树脂制作测试样本，以研究与甲基丙烯酸化树枝状大分子交联的义齿基托树脂的弯曲性能、聚甲基丙烯酸甲酯微珠的表面显微硬度以及聚甲基丙烯酸甲酯微珠溶胀层的厚度。样本进行自凝，所有样本在37°C水中储存24小时。一半样本再在37°C水中浸泡6个月（水储存期：24小时和6个月）。采用三点弯曲试验测量弯曲强度和弯曲模量（每组n = 10）。使用方差分析和纽曼-基尔斯检验进行统计分析，显著性水平为0.05。
热处理和水储存期对弯曲强度有显著影响。HT130的弯曲强度显著高于其他组。HT130的聚甲基丙烯酸甲酯微珠表面显微硬度显著高于其他组。HT100和HT130的聚甲基丙烯酸甲酯微珠溶胀层厚度显著降低。
130°C热处理后弯曲强度和表面显微硬度增加。热处理后聚甲基丙烯酸甲酯微珠溶胀层厚度降低。
