纤维增强聚甲基丙烯酸甲酯材料的研究进展

［摘要］ 聚甲基丙烯酸甲酯(PMMA)义齿基托材料是目前使用最广泛的义齿基托材料,但其在机械性能方面还存在一定缺陷,基于此,近年来许多学者致力于对其改性的研究。研究结果显示,添加一些纤维增强材料,可以使PMMA义齿基托材料的性能得到明显改善。本文结合近十几年来发表的文章,主要强调纤维对其性能的影响,对PMMA义齿基托材料改性的研究进展作一综述。     

纤维增强义齿基托的研究进展

纤维增强义齿基托是提高义齿基托材料机械性能的一项新技术，也是近年来基托树脂材料改性研究的一个较活跃领域。本文简要介绍纤维增强义齿基托的研究发展与现状以及展望。     

聚乙烯纤维加强聚甲基丙烯酸甲酯的机械性能测试

目的　观察聚乙烯纤维对聚甲基丙烯酸甲酯是否有加强作用。方法　采用自制模具,制作化学固化聚甲基丙烯酸甲酯(PMMA)组、化学固化PMMA加0·25 mm结扎丝组、化学固化PMMA加Ribbond聚乙烯纤维组3组试样,共28个。用万能材料实验机进行三点弯曲实验,记录试样的弯曲强度和弹性模量值,并进行统计分析。结果　化学固化PMMA组的弯曲强度为(51·383±2·761)MPa,弹性模量为(179 1·2±113·760)MPa。化学固化PMMA加 0·25 mm结扎丝组的弯曲强度为(58·725±1·218)MPa,弹性模量为(209 2·76±120·280)MPa。Ribbond聚乙烯纤维加强组的弯曲强度为(80·975±2·580)MPa,弹性模量为(286 6·53±107·510)MPa。经单因素方差分析各组之间皆有显著性差异(P<0·001)。Newman-Keuls法检测各组之间均有显著性差异(P<0·05)。结论　Ribbond聚乙烯纤维加强能显著提高聚甲基丙烯酸甲酯的弯曲强度和弹性模量。     

聚甲基丙烯酸甲酯基托材料聚合与性能增强的研究进展

本文主要介绍聚甲基丙烯酸甲醋（Polymethyl methacrylate,PMMA）义齿基托材料的研制、不同聚合方法对其力学性能的影响以及关于PMMA性能增强的研究进展.对新型的聚合工艺技术及PMMA基托材料的改进做出初步探讨并展望其发展趋势.     

改善聚甲基丙烯酸甲酯基托材料抗菌及其机械性能的研究进展

基托作为活动矫治器的主体，在儿童咬合诱导中已得到广泛的应用；目前临床上常用的矫治器基托材料多为自凝树脂，主要成分为聚甲基丙烯酸甲酯（PMMA）。由于儿童的生长发育特点对矫治器基托材料的性能有着特殊要求，该文从活动矫治器基托的清洁抗菌和机械强度方面进行综述，以期更好地应用于儿童咬合诱导。     

聚甲基丙烯酸甲酯义齿基托材料聚合成型工艺的研究进展

本文着重介绍了聚甲基丙烯酸甲酯(PMMA)义齿基托材料的热压注塑成型、电热聚合固化、微波固化及快速自控气压和液压热聚合等固化成型模式的工作原理、方法、创新点及存在的缺陷等，初步探讨了PMMA义齿基托材料在其聚合成型工艺方面的研究进展。     

纤维增强复合树脂的基础研究现状

纤维增强高分子复合材料作为一种新型的材料，具有低密度，高强度，高模量以及耐腐蚀的优点。本主要介绍它的基础研究现状，包括机械性能，界面情况，尺寸稳定性与吸水率，细菌的吸附四个方面。     

纤维增强义齿基托树脂的应用研究

纤维增强义齿基托树脂作为提高义齿基托材料机械性能的一种技术,它所采用的增强纤维有玻璃纤维、碳纤维、芳纶纤维及超高模量聚乙烯纤维。本文通过对纤维增强义齿基托树脂有关文献的回顾,认为纤维的含量、纤维的埋入方式、纤维的表面处理等因素,均影响纤维增强义齿基托材料的机械性能。     

纤维增强复合材料在口腔医学中的应用

纤维增强复合树脂材料（FRC）是一种工程材料,近年来逐渐引入到口腔材料领域中,因而FRC成为目前国际国内研究的热点。FRC不仅可用于义齿基托加强和修补,还可以应用于牙周夹板,固定义齿修复。桩核系统,种植义齿,覆盖义齿和正畸保持器等。     

微波加热法及常规水浴法处理聚甲基丙烯酸甲酯基托材料的性能比较研究

探讨微波加热法处理聚甲基丙烯酸甲酯基托材料的力学性能。方法分别采用热水浴法及微波加热法处理的ＰＭＭＡ基托材料,测试其力学性能。结果微波法可获得与热水浴法处理的基托材料相似,甚至更好的力学性能。结论经微波处理所获得的ＰＭＭＡ具有能满足临床的力学性能。     

Flexural strength of heat-polymerized polymethyl methacrylate denture resin reinforced with glass, aramid, or nylon fibers.

STATEMENT OF PROBLEM: Despite the favorable properties of conventional PMMA used as a denture base material, its fracture resistance could be improved. PURPOSE: This in vitro study was performed to determine whether the flexural strength of a commercially available, heat-polymerized acrylic denture base material could be improved through reinforcement with 3 types of fibers. MATERIAL AND METHODS: Ten specimens of similar dimensions were prepared for each of the 4 experimental groups: conventional acrylic resin and the same resin reinforced with glass, aramid, or nylon fibers. Flexural strength was evaluated with a 3-point bending test. The results were analyzed with a 1-way analysis of variance. RESULTS: All reinforced specimens showed better flexural strength than the conventional acrylic resin. Specimens reinforced with glass fibers showed the highest flexural strength, followed by aramid and nylon. CONCLUSION: Within the limitations of this study, the flexural strength of heat-polymerized PMMA denture resin was improved after reinforcement with glass or aramid fibers. It may be possible to apply these results to distal extension partial denture bases and provisional fixed partial dentures.     

四种加工方式对基托树脂力学性能的影响

目的 探讨不同混合和热加工方式对义齿基托树脂力学性能的影响,探讨捏炼混合+电烤箱加热的固化方式可否提高基托树脂的力学性能.方法 制作4组基托树脂试件,第1组:常规混合+水浴加热;第2组:捏炼混合+水浴加热;第3组:常规混合+电烤箱加热;第4组:捏炼混合+电烤箱加热.测定树脂的表面硬度、弯曲强度和弯曲模量、冲击强度.结果 第1～4组试件表面硬度分别为19.4、21.2、22.3、23.2 N/mm2,弯曲强度分别为58.58、63.32、66.73、63.76 MPa,冲击强度分别为1.42、1.53、1.77、1.78 KJ/m2,弯曲模量分别为2311.38、2417.82、2566.36、2400.37 MPa.结论 与常规混合+水浴加热方式相比,捏炼混合+电烤箱加热方式制作的树脂有较高的表面硬度和冲击强度,综合力学性能较佳.     

Impact strength of denture polymethyl methacrylate reinforced with continuous glass fibers or metal wire

The impact strength of heat-cured acrylic resin test specimens that had been reinforced in various ways was compared in this study. Ten rectangular test specimens were fabricated for each test group. The strengtheners included 1.0-mm-diameter steel wire and continuous E-glass fibers. Both notched and unnotched test specimens were tested in a Charpy-type impact test. In a further analysis the concentration of glass fibers in the test specimens was determined and plotted against the impact strength of the test specimens. The results showed that, compared with the unreinforced specimens, both types of reinforcement increased the impact strength of the test specimens considerably (p < 0.001). There was no clear difference between the mean impact strength value of the test specimens reinforced with metal wire and that of the specimens reinforced with glass fiber. The correlation coefficient between the fiber concentration of the test specimens and their impact strength was 0.818 (p < 0.005). Specimens with fiber concentrations greater than 25 wt% yielded to the higher impact strength more readily than those with metal wire reinforcement did.     

Effect of polyaramid fiber reinforcement on the strength of 3 denture base polymethyl methacrylate resins

Purpose The interactive effects of synthetic polyaramid reinforcement fibers on the transverse strength of intact and repaired heat‐polymerized denture base acrylic resins were investigated. Materials and Methods Three polymethylmethacrylate (PMMA) polymers were tested: Acron MC (GC International Corp, Scottsdale, AZ), Lucitone 199 (Dentsply International Inc, York, PA), and Microlon (The Hygienic Corp, Akron, OH). With each polymer, there were 2 controls and 4 experimental groups (n = 9 per group). The treatment groups were intact heat‐polymerized PMMA control, PMMA with unreinforced repair, PMMA with polyaramid reinforced repair, intact polyaramid reinforced heat‐polymerized PMMA control, polyaramid reinforced PMMA with unreinforced repair, and polyaramid reinforced PMMA with polyaramid reinforced repair. The transverse fracture strengths of the samples were measured with a 3‐point bending test on a Zwick Universal Testing Machine (Zwick of America, Inc, East Windsor, CT). Results The highest mean strength at fracture was recorded with intact polyaramid reinforced heat‐polymerized PMMA controls for all resins. Analysis of variance showed significant differences in transverse strength (p < .05 ) by experimental group, by material, and by interaction of group and material. Tukey HSD (honestly significant difference) Multiple Comparisons Test (α= 0.05) showed that intact polyaramid reinforced heat‐polymerized PMMA controls were significantly stronger than intact heat‐polymerized PMMA controls and all the other treatment groups. Use of polyaramid reinforcement in repair of unreinforced PMMA or polyaramid reinforced PMMA did not result in significantly increased transverse strength. Conclusions Polyaramid reinforcement significantly increased the transverse strength of intact heat‐polymerized PMMA. Polyaramid fibers did not significantly increase strength to reinforce PMMA repairs.     

不同类型义齿清洁剂对热凝基托树脂物理机械性能的影响

目的：观察不同类型义齿清洁剂对热凝基托树脂物理机械性能的影响。方法：将同样规格的热凝基托树脂试件,按使用说明分别浸泡在 Polident 清洁片或 Steradent 清洁片或0．5％次氯酸钠溶液和蒸馏水中60 h,处理后的试件在万能材料试验机和表面粗糙度测试仪上分别测其弯曲强度、弹性模量（n ＝10）和表面粗糙度（n ＝10）。结果：Polident、Steradent 对热凝基托树脂的弯曲强度和弹性模量的影响与蒸馏水组相比差异无统计学意义（P ＞0．05）,0．5％次氯酸钠组的弯曲强度和弹性模量小于其他组（P ＜0．05）;热凝基托树脂粗糙度4组之间差异无统计学意义（P ＞0．05）。结论：Polident、Steradent 均不影响热凝基托树脂的物理机械性能,0．5％次氯酸钠对热凝基托树脂的粗糙度无影响,而使其弯曲强度及弹性模量有所降低。     

Influence of various metal oxides on mechanical and physical properties of heat-cured polymethyl methacrylate denture base resins

PURPOSE

To evaluate the effect of various metal oxides on impact strength (IS), fracture toughness (FT), water sorption (WSP) and solubility (WSL) of heat-cured acrylic resin.

MATERIALS AND METHODS

Fifty acrylic resin specimens were fabricated for each test and divided into five groups. Group 1 was the control group and Group 2, 3, 4 and 5 (test groups) included a mixture of 1% TiO₂ and 1% ZrO₂, 2% Al₂O₃, 2% TiO₂, and 2% ZrO₂ by volume, respectively. Rectangular unnotched specimens (50 mm × 6.0 mm × 4.0 mm) were fabricated and droptower impact testing machine was used to determine IS. For FT, compact test specimens were fabricated and tests were done with a universal testing machine with a cross-head speed of 5 mm/min. For WSP and WSL, discshaped specimens were fabricated and tests were performed in accordance to ISO 1567. ANOVA and Kruskal-Wallis tests were used for statistical analyses.

RESULTS

IS and FT values were significantly higher and WSP and WSL values were significantly lower in test groups than in control group (P<.05). Group 5 had significantly higher IS and FT values and significantly lower WSP values than other groups (P<.05) and provided 40% and 30% increase in IS and FT, respectively, compared to control group. Significantly lower WSL values were detected for Group 2 and 5 (P<.05).

CONCLUSION

Modification of heat-cured acrylic resin with metal oxides, especially with ZrO₂, may be useful in preventing denture fractures and undesirable physical changes resulting from oral fluids clinically.     

分光光度法与目测法测量义齿基托树脂色稳定性的比较研究

目的 探讨分光光度法与目测法测量义齿基托树脂色稳定性的相关性,以期确定分光光度法中的界值色差.方法 选取A、B两种红色义齿基托树脂(牙科丽义齿基托聚合物BQ-1,色号分别为2和3),各制作33个圆形试片,对试片一侧进行不同时间的光照处理,使其变色.30名色觉正常且具有1年以上口腔修复临床经验的口腔医学研究生分别对试片进行目测判定,结果计为"不变色"、"轻微变色"或"严重变色".用SP62分光光度仪测量试片两侧的色度值L*、a*、b*,计算色差△E.以色差△E为横坐标,以目测观察判定为"严重变色"的人数比例为纵坐标,绘制两种树脂的Logistic曲线.以50%观察者判定为"严重变色"时所对应的色差值,作为分光光度法的界值色差.结果 A、B树脂Logistic曲线的R2值分别为0.93和0.94;界值色差分别为2.87、2.82.结论 义齿基托树脂色稳定性评价中,分光光度仪数值测色方法与目测方法具有较好的相关性,不同色号的红色义齿基托树脂的界值色差相近.

Abstract：

Objective To explore the relationship between the spectrophotometric and visual methods in evaluating the color stability of denture base resin, and determine the threshold color difference of denture base resin in the spectrophotometric method. Methods Two kinds of denture base resin were respectively fabricated into 33 specimens whose color differences varied from indistinguishable to obvious.Each of the specimens was assessed respectively by 30 human observers and a SP62 spectrophotometer. The results of visual assement were recorded as "indistinguishable change", "light change" or "severe change",while the spectrophotometric color differences ( △ E) were calculated. In each group, a logistic curve was explored to determine the relationship between the color difference ( △ E) and the ratio of "severe change".Results The R squares of logistic curves were 0. 93 and 0. 94 respectively. The threshold color differences in the spectrophotometric method were 2. 87 and 2. 82 respectively. Conclusions A high relevance between the spectrophotometric and visual methods in evaluating the color stability of denture base resin was found.The threshold color differences for different color denture base resins were similar.     

Impact strength of denture polymethyl methacrylate reinforced with different forms of E-glass fibers

Abstract

Objective. The purpose of this in vitro study was to determine the reinforcing effect of different forms and concentrations of E-glass fibers on impact strength of denture polymethyl methacrylate. Materials and method. A total of 91 rectangular specimens (84 specimens for test groups and seven for control group) of a heat-cured acrylic resin were fabricated. The test specimens were prepared by modifying the polymethyl methacrylate with the addition of different concentrations (2.5%, 3%, 4%, 5% by volume) of three types (chopped strand mat, woven and continuous unidirectional fibers) of E-glass fibers. The impact strength was evaluated using the Charpy method. Results. While the 5% continuous glass fiber added test group showed the highest mean impact strength, the lowest value belonged to the 2.5% woven glass fiber containing group. When the impact strength values of chopped strand mat and continuous unidirectional glass fiber added groups at all concentrations were compared with the control group, the differences were statistically significant. The impact strength values of the woven glass fiber added groups at all concentrations were higher than that of the control group. However, the difference was non-significant. Conclusion. The impact strength of PMMA was enhanced by including E-glass fibers, increasing parallel with the fiber concentration.