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.     

义齿资料基托热压灌注成型新工艺——颜色稳定性的比较研究

目的；分析比较成型后的基托塑料可能发生的变色。方法：不同粉、液比例灌注成型的基托塑料和常规模压成型的基托塑料，用分光测色仪观察颜色稳定性，结果，粉、液以２：１体积比灌注成型的义齿基托热压灌注成型的义齿基托，表面平整光滑，色调，饱和度与常模压成型的义齿基托同，而其表面可抛光性优于常规法。结论：２种方法成型的义齿基托对紫外线的敏感性无显著性差异。     

聚合方式对义齿基托树脂中残余甲基丙烯酸甲酯单体含量的影响

目的研究聚合方式对义齿基托树脂中残余甲基丙烯酸甲酯含量的影响。方法按照不同的聚合方式,将实验分为3组,每组制备3块试验样块.按照YY0270-2003规定的气相色谱法实验方法测试各组样品的甲基丙烯酸甲酯单体（MMA）含量。结果不同聚合方式得到的材料中MMA的百分含量明显不同,以微波聚合方式得到的基托材料残余单体含量最低。结论聚合方式对义齿基托材料残余单体含量具有显著影响。     

聚甲基丙烯酸甲酯义齿基托材料清洁抗菌研究进展

聚甲基丙烯酸甲酯是一种常用的义齿基托材料，由于自洁作用差，基托聚合物的溶出和固化时产生的微孔易在其表面形成菌斑、牙石的沉积。因此迫切需要应用较理想的方法清洁基托表面、提高基托自身的抗菌性。本文就义齿基托材料清洁抗茵机制及方法作一综述。     

聚甲基丙烯酸甲酯义齿基托材料清洁抗菌研究进展

聚甲基丙烯酸甲酯是一种常用的义齿基托材料,由于自洁作用差,基托聚合物的溶出和固化时产生的微孔易在其表面形成菌斑、牙石的沉积。因此迫切需要应用较理想的方法清洁基托表面、提高基托自身的抗菌性。本文就义齿基托材料清洁抗菌机制及方法作一综述。     

聚甲基丙烯酸树脂义齿基托消毒的研究进展

活动义齿包括全口义齿的树脂基托在临床上广泛应用,基托与口腔黏膜紧密贴合,基托表面极易聚集病原菌,在义齿基托的制作调改以及日常戴用过程中对其消毒极为必要。现就义齿基托消毒的现状做一综述,为临床工作提供指导。     

义齿塑料基托热压灌注成型新工艺制作义齿临床体会

采用义齿塑料基托热压灌注成型新工艺，制作可摘义齿８６件，该工艺具有以下优点：简化义齿制作工序；自动控制聚合过程；义齿适应性好；无菲边，不增高咬合；无气泡发生。因此，可以认为，该工艺作为一种常规成型技术的替代方法，有推广使用的价值。     

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。     

义齿基托塑料电热聚合器的研制

介绍一种新的用于口腔修复专业的甲基丙烯酸甲脂热处理聚合设备。该设备可以将树脂的加压和热处理功能合为一体。有６８℃和１００℃两个温度档，并且具有相应符合树脂材料热聚合工艺规范要求的恒温时间。整个聚合过程无需人工管理。该产品操作简单、耐用、节电、无污染，实用性强。     

微波能固化义齿基托材料的实验性研究

目的 了解微波能加热处理义齿基托材料的力学性能和收缩变化。方法 采用微波能和水浴责任中方法加热固化义齿基托树脂。进行挠曲强度、硬度和收缩率的对比分析。结果 微波能固化的基托材料的力学性能与水溶法相比无显著性差异。但具有更好的尺寸精确性。结论 微波能是一种良好的固化义齿基托材料的热源。     

丙烯酸酯类义齿基托材料的研究进展

本文介绍了使用新型热聚合器、树脂上光剂、化学清洁剂改善热固化型丙烯酸酯类义齿基托表面光洁度和在基托材料中加入抑菌剂以减少基托表面细菌粘附的方法。在基托中加入玻璃纤维、超高分子量聚乙烯纤维等提高基托机械强度的材料研究新进展。     

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。     

芳纶纤维增强聚甲基丙烯酸甲酯基托的机械性能

目的：研究芳纶纤维增强聚甲基丙烯酸甲酯（ＰＭＭＡ）基托的机械性能。方法：将Ｔｗａｒｏｎ，ＡＰＭＯＣ芳纶纤维分别按体积分数１％、２％埋入ＰＭＭＡ基托树脂内，然后测定芳纶纤维增强ＰＭＭＡ基托的弯曲强度、冲击强度及弹性模量。结果：１％、２％芳纶纤维各组与对照组相比，弯曲强度、冲击强度均有明显提高（Ｐ＜０．０１），但弹性模量没有明显提高（Ｐ＞０．０５）。结论：芳纶纤维能提高ＰＭＭＡ基托的弯曲强度和冲击强度。     

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.     

The nature of the interface between polymethyl methacrylate denture base materials and soft lining materials

Four of the commonly used resilient denture lining materials were investigated. They were of different chemical composition, physical forms and processing cycles. Scanning electron microscope examinations of the interface between the liners and the regular acrylic resin base material were carried out in an attempt to assess the bonding of these materials to the denture base, and to evaluate the reliability of their use. The physical and mechanical bonding properties of the resilient lining materials to acrylics were studied, which included tensile, shear, peel and compression tests to measure the efficacy of the joint between the acrylic and the lining materials and its resistance to various external damaging loads. The effect of water on the liner/denture base interface and on the liner's bonding properties to acrylics was also investigated, and the validity of roughening the tissue surface of the denture base prior to processing the liner was assessed.

The findings point to the advisability of using the acrylic type of soft liners whenever resilient liners are indicated. Roughening the fitting surface of the denture base to which the resilient lining materials are to be applied has a weakening effect on the bond between the lining and the denture base. Long-term exposure of the liners to water has a destructive effect. The infusion of the water into the material leads to swelling and stresses build up at the denture base interface and these tend to promote distortion and reduction in bonding.     

Effect of fiber reinforcement on impact strength of heat polymerized polymethyl methacrylate denture base resin: in vitro study and SEM analysis

PURPOSE

The aim of this in-vitro investigation was to describe the effect of reinforcement with different fibers on impact strength of heat polymerized polymethyl methacrylate (PMMA) denture base resin and to analyze the effect of surface treatment of the fibers on the impact strength.

MATERIALS AND METHODS

The specimens were fabricated from the dies formed as per standard ASTM D4812. 2% by weight of glass, polyethylene and polypropylene fibers were incorporated in the PMMA resin. The Izod impact testing was performed on the unnotched specimens and the values obtained were analyzed using appropriate one way ANOVA, followed by unpaired t-test. Fractured ends of the samples were subjected to the SEM analysis.

RESULTS

The polypropylene fibers with plasma treatment showed the highest impact strength (9.229 × 10² J/m) followed by the plasma treated polyethylene fibers (9.096 × 10² J/m), untreated polypropylene fibers (8.697 × 10² J/m), untreated polyethylene fibers (7.580 × 10² J/m), silane treated glass fibers (6.448 × 10² J/m) and untreated glass fibers (5.764 × 10² J/m). Also the surface treatment of all the fibers has shown the significant improvement in impact strength. Findings of the SEM analysis justified the improvement in impact strength after surface treatment.

CONCLUSION

Reinforcement with the fiber is an effective method to increase the impact strength of PMMA denture base resin. The surface treatment of fibers further increases the impact strength significantly.