聚甲基丙烯酸甲酯微球改型的人工树脂牙耐磨性能和硬度的研究

Wear resistance and hardness of a polymethyl methacrylate pearls modified artificial resin tooth

目的研究比较聚甲基丙烯酸甲酯（PMMA）微球改型的人工树脂牙与另外5种常人工树脂牙的耐磨耗特性和硬度。方法本实验选取6种人工牙（3种高交联树脂牙：Vita Lingoform,Premium,Portrait IPN;2种合成树脂牙Yamahachi PX,Kaiplus和传统的PMMA树脂牙Yamahachi FX,n=8）,其中Vita Lingoform为PMMA微球改型的新型树脂牙。另外,选取牙釉质样本为对照组。使用高温微动摩擦试验机进行反复滑动摩擦实验后用三维轮廓扫描仪确定磨痕的深度损失和体积损失,并用微压痕法测定各组样本的维氏硬度,分析统确定各组样本之间磨耗损失和硬度的差异以及人工树脂牙的磨耗损失与维氏硬度值进行相关性分析。结果磨痕分析结果显示,6种人工树脂牙以及牙釉质的磨耗损失（深度损失μm,体积损失mm^3×10^-3）差异有统计学意义（H深度损失=95.01,H体积损失=93.96,P〈0.001）。加入PMMA微球的Vita Lingoform组树脂牙的磨耗损失量（1.58,1.377）低于传统的PMMA树脂牙Yamahachi FX（2.22,1.983,P〈0.001）,但高于复合树脂牙Yamahachi FX和Kaiplus（1.01~1.06,0.935~0.990,P〈0.05）。同时,Vita Lingoform组树脂牙组（37.2）的硬度低于复合树脂牙组（41.0~43.1,P〈0.05）,高于传统的PMMA树脂牙Yamahachi FX（25.9,P〈0.001）。高交联组树脂牙Premium和Portrait IPN的磨耗损失量（1.57~1.64,1.360~1.409）和硬度（36.1~37.4）与VitaLingoform组差异均没有统计学意义（P〉0.05）。6种人工树脂牙的耐磨性能和硬度均低于牙釉质对照（0.31,0.213;68.2,P〈0.001）。相关性分析的结果显示,硬度与深度损失（r=-0.896）和体积损失（r=-0.893）均成负相关性。结论 PMMA微球改型的树脂牙耐磨性能和硬度均高于传统的丙烯酸树脂牙,但低于复合树脂人工牙和天然牙釉质,且与其他高交联人工树脂牙差异不大。

Objective The purpose of this study was to evaluate the wear resistance and hardnessof a polymethyl methacrylate（PMMA）pearls modified artificial resin tooth compared to five commerciallyavailable denture teeth. Methods Eight specimens of six different artificial resin teeth（3 highly cross-linked acrylic resin teeth：Vita Lingoform,Premium and Portrait IPN;2 composite resin teeth：YamahachiPX and Huge Kaiplus and 1 conventional acrylic resin teeth Yamahachi FX）were tested. One of theartificial resin teeth（Vita Lingoform）is a new PMMA pearls modified denture teeth. Human enamel wasused as a control group. The specimens were mounted to a high temperature fretting abrasive tester with apin-on-block design,and the vertical loss and volume loss of the samples were measured using three-dimensional surface profilometer. Hardness of the samples was determined using a micro-Vickers hardnesstester. Data of wear loss and Vickers hardness were statistically analyzed with the Kruskal- Wallis H nonparametric test and the Spearman correlation coefficient was used to determine the relationship between the wear loss（vertical loss and volume loss）and hardness. Results The six artificial resin teeth and human enamel tested showed significant differences in the vertical loss（μm）and volume loss（mm^3×10^-3）（Hvertical loss= 95.01,Hvolume loss= 93.96,P〈0.001）. Vertical loss and volume loss of the PMMA pearls modified Vita Lingoform group（1.58,1.377）were higher than those of composite resin teeth（1.01-1.06,0.935-0.990,P〈0.05）,but lower than that of conventional acrylic resin teeth Yamahachi FX（2.22,1.983,P〈0.001）. The Vita Lingoform group（37.2）showed intermediate hardness values,which are significantly lower than those of the composite resin groups（41.0-43.1,P〈0.05）. The conventional acrylic resin teeth（25.9）demonstrated the lowest hardness values（P〈0.001）. No significant differences for wear loss and Vickers hardness values were found between the Vita Lingoform and the other two highly cross- linked acrylic resin teeth Premium and Portrait IPN（P〉0.05）. The human enamel group revealed the highest wear resistance and Vickers hardness values（0.31,0.213;68.2,P〈0.001）among all the materials tested. Moreover,A negative relationship was found between hardness and vertical loss（r =-0.896）and volume loss（r =-0.893）. Conclusions The PMMA modified artificial resin teeth revealed improved wear resistance and hardness values compared to the conventional acrylic resin denture teeth. However,it showed less wear resistance and hardness values than the composite resin teeth and human enamel. No significant differences were found for the wear loss and hardness values among the three highly cross-linked artificial resin teeth.