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目的认为纤维的含量,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。     

义齿基托机械性能的加强

目前临床上制作义齿最常用的材料为聚甲基丙烯酸甲酯(PMMA),PMMA具有操作简便,色泽美观,易于抛光,性能稳定等各项优点,但它的机械性能并不能完全达到修复的要求,义齿基托的折裂由于材料本身的机械强度与韧性不足及其它多因素共同引起,为解决义齿基托的折裂,通常有两种方法来增强PMMA的抗冲击性能.(1)PMMA化学成分的调整,例如加入橡胶接枝共聚物;(2)PMMA基质中加入其它物质,例如碳素纤维,玻璃纤维,超高模量聚乙烯.     

两种不同材料总义齿基托菌斑与义齿性口炎的临床分析

目的分析两种不同基托材料总义齿基托组织面的菌斑分布情况与义齿性口炎的关系。方法利用菌斑显示剂涂布上颌基托组织面记录菌斑分布情况，采用贞森绅拯的义齿性口炎分级方法调查树脂、钴铬合金整体铸造基托义齿性口炎的发病率，分析基托菌斑与义齿性口炎之间的关系。结果在树脂基托与整体铸造基托的菌斑分布分析中发现：在上颌总义齿的基托组织面上菌斑附着并没有显著的差别，而在对义齿性口炎的观察中发现：树脂、整体铸造基托总义齿的义齿性口炎的发病率分别28．47％、10，71％。树脂基托引发义齿性口炎的可能性却远高于钴铬合金体铸造基托。结论对于基托组织面的菌斑分布而言，树脂基托与铸造基托之间没有显著差异；但是两种基托材料对义齿性口炎的发病率的影响却有着显著差异；与钴铬舍金整体铸造基托相比较，树脂基托更易引起义齿性口炎；义齿性口炎的发生与菌斑分布没有相关关系。     

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。     

国内外几种自然色义齿基托树脂主要性能比较研究

本研究选择了具有代表性Ｌｕｃｉｔｏｎｅ，Ｍｅｌｉｏｄｅｎｔ，Ｐｉｇｅｏｎ，ＨＯ－１，ＨＯ－２等５种自然色义齿基托树脂，对其抗弯，吸水性，溶解性等主要性能进行了对比研究，结果表明，牌号为Ｌｕｃｉｔｏｎｅ的基托树脂冲击强度最佳，其他性能，５种义齿基托树脂没有显著的差异。     

超强聚乙烯纤维增强树脂基托性能的实验研究

目的：评价在义齿基托树脂中加入超强聚乙烯纤维后的挠曲性能。方法：在义齿基托树脂中加入不同质量分数的超强聚乙烯纤维，测试其挠曲强度，与未加入纤维的基托树脂对比；同时在扫描电镜下观察其断面情况。结果：加入超强聚乙烯纤维的基托树脂的挠曲强度要高于对照组，在3．5wt％时达最大值，电镜结果显示纤维在基质中均匀分布。结论：超强聚乙烯纤维能提高义齿基托的挠曲强度。     

金属纤维在基托材料中作用的研究

义齿基托折断是口腔修复中仍未解决的问题，尤其是上颌总义齿的纵折．为使基托结构较薄，又有足够的强度来承受强大的咀嚼力，临床上除了根据力学特性来指导临床设计工作以外，大多采用机械方法来提高义齿基托材料的强度，如局部埋入不锈钢丝、不锈钢管、尼龙丝网等物理措施，但效果不全尽人意．作者根据有机高分子复合材料的基本原理，研制出特殊形态的ＤＭＣ－１铜基合金纤维，经偶联剂ＫＨ５５０处理后，按一定的重量比混入常规的基托材料中形成复合材料，能显著提高材料的弯曲强度和拉伸强度，取得较满意的效果．     

金属纤维增强树脂基托材料的研制

义齿基托折断是口腔修复中仍未解决的问题,尤其是上颌总义齿的纵折.研究了一种新型的齿科复合材料——金属纤维增强树脂基托材料的加工工艺,经弯曲强度测试、X射线光电子能谱仪扫描、电镜观察、电子探针扫描证实性能优于普通的树脂基托材料;急性毒性试验和临床应用试验初步证实金属纤维增强树脂基托材料是一种很有应用前途的新颖基托材料.     

总义齿基托三点适度伸展的固位作用

<正> 关于总义齿基托的伸展、多数著作均按口腔解剖部位进行了阐述。笔者在多年的口矫临床实践中,见到很多总义齿,因上下颌前弓区、上颁结节外侧的颊间隙处及下颌舌侧翼缘区的后部的基托伸展不足而招致义齿严重脱位,经延长上述部位一处或两处的基托后,固位明显增强了,其前提是其他部位的基托也必     

Effect of glass fiber reinforcement on the flexural strength of different denture base resins.

OBJECTIVE: Different types of fibers have been added to polymer materials to improve their mechanical properties. Glass fibers have been used in either continuous or woven form as a strengthening material. The aim of this study was to investigate the effect of a new glass fiber reinforcement system on the flexural strength of three different denture base resins (heat polymerized, autopolymerized, and photopolymerized). METHOD AND MATERIALS: Ninety specimens were formed in a specially designed mold to produce identical specimens in accordance with each manufacturer's recommendations. RESULTS: The fibers of Stick and Stick Net were well impregnated with the resin of polymer matrix. Stick and Stick Net reinforcement significantly enhanced the flexural strength of the tested specimens. In all groups, specimens reinforced with Stick glass fibers exhibited the highest flexural strength, followed by Stick Net glass fibers. The control group specimens without fiber exhibited the lowest values. CONCLUSION: The process of reinforcement of denture base resins with glass fiber may be a useful means of strengthening denture bases beyond their normal limits.     

The effect of glass fiber reinforcement on the residual monomer content of two denture base resins.

OBJECTIVE: The amount of residual monomer is one of the principal factors affecting the properties of acrylic resin denture bases. In recent years, glass fibers have been used to strengthen denture base resins. The purpose of this study was to investigate the effect of glass fiber reinforcement on the amount of residual methyl methacrylate released from two different denture base resins (heat cured and autopolymerized). METHOD AND MATERIALS: Continuous unidirectional and woven preimpregnated glass fiber reinforcements (Stick and Stick Net) were used to reinforce heat-curing and autopolymerizing denture base resins. RESULTS: The release of residual methyl methacrylate from heat-cured and autopolymerized test specimens reinforced with glass fibers was significantly higher than that from unreinforced test specimens. Stick Net glass fiber reinforcement resulted in significantly higher residual monomer release than did Stick glass fiber reinforcement. Test specimens made from heat-cured denture polymethyl methacrylate released less residual methyl methacrylate than did specimens made from autopolymerized polymethyl methacrylate. CONCLUSION: Glass fiber reinforcement increases the residual monomer content of denture base resins. The level of residual monomer ranged from 0.11% to 0.37% in heat-cured resin and from 0.18% to 0.46% in autopolymerized denture base resin.     

Reinforcement of poly(methyl methacrylate) denture base with glass flake.

OBJECTIVES: Since the introduction of poly(methyl methacrylate) as a denture base material, it has suffered from having relatively poor mechanical properties. Many methods of improving its strength and toughness have been investigated. Most of these have not been adopted due to: increased cost, the need for specialist processing equipment or increased laboratory time due to more complicated procedures. Glass flake has been used as a reinforcing agent in many industrial polymers, but is as yet untested with denture base acrylic materials. The aim of this study is to evaluate the effect of adding glass flake to denture base acrylic powder on the fracture toughness of the set material. METHODS: Glass flake was added in 5, 10 or 20% w/w to Trevalon denture base powder. The material was mixed, flasked, packed and processed in a manner typical for a denture base material. Fracture toughness was determined using a double torsion test technique. RESULTS: The addition of glass flake gave up to a 69% increase in fracture toughness compared to plain Trevalon material. The addition of 5% glass flake lead to an improvement in fracture toughness that was statistically significant compared to both plain Trevalon and the 10 and 20% groups. SIGNIFICANCE: The significant improvement in fracture toughness of a denture base acrylic material using glass flake is an extremely promising result. Other mechanical properties will require testing before glass flake can be recommended as a reinforcing agent for denture base acrylic materials.     

The reinforcement of dentures

The material most commonly used for the fabrication of complete dentures is poly (methyl methacrylate) (PMMA). This material is not ideal in every respect and it is the combination of virtues rather than one single desirable property that accounts for its popularity and usage. Despite its popularity in satisfying aesthetic demands it is still far from ideal in fulfilling the mechanical requirements of a prosthesis. The fracture of dentures may be due to the mechanical properties of the acrylic resin or may be due to a multiplicity of factors leading to failure of the denture base material. Generally, there are three routes which have been investigated to improve the impact properties of PMMA: the search for, or development of, an alternative material to PMMA; the chemical modification of PMMA such as by the addition of a rubber graft copolymer; and the reinforcement of PMMA with other materials such as carbon fibres, glass fibres and ultra-high modulus polyethylene. The following review of attempts to improve the mechanical properties of denture base material takes account of papers published during the last 30 years.     

A Review of Fiber-Reinforced Denture Base Resins

Purpose One method of reinforcing denture base material is to use fiber composite reinforcement. Different types of fibers, such as glass (GF), carbon/graphite, aramid, and ultrahigh-modulus polyethylene (UHMP) fibers have been tested for this purpose. Materials and Methods This article reviews the studies conducted on the fiber-reinforced denture base resin systems. Results The literature has reported that the fiber concentration and its adhesion to polymer matrix influences the transverse strength of the fiber composite. The highest transverse strength value (265 MPa) with polymethyl methacrylate (PMMA) was obtained by incorporating 58 wt% GF into the resin. UHMP fibers incorporated into PMMA resin yielded the highest impact strength value (134 kJm^-2) of the fiber-PMMA composites. Conclusions Despite the improved mechanical properties of fiber-reinforced denture materials, further research is required to show the clinical usefulness of the fiber reinforcement.     

Fabrication of Complete Denture Bases Reinforced with Polyethylene Woven Fabric

Incorporation of 5 layers of woven, high-modulus polyethylene fiber into acrylic resin denture bases produces substantial improvements in mechanical properties and dimensional changes. A modified split-pack technique has been developed using conventional dental-laboratory compression molding to accommodate multiple layers of woven fabric in complete denture bases. A recess formed in the resin by a spacer allows the reinforcement to be embedded in the denture base without exposing the fibers. Embedded fibers do not compromise the esthetics of complete dentures.     

Reinforcement of denture base resin with short-rod glass fiber

The present study investigated the feasibility of a high short-rod fiber content in denture base resins using polymethylmethacrylate (PMMA) powder with a small particle diameter. The effects of fiber contents on mechanical properties of composite resins were studied. A commercial denture base PMMA powder (AC; average particle size, 150 microm) and an industrial PMMA powder (MB; average particle size, 4 microm) were selected. Short-rod glass fibers were mixed with the two powders at a mass ratio of 0-50%. Flexural strengths and moduli of the mixtures were evaluated by a three-point bending test. The flexural strength of AC composites did not change regardless of fiber content, while that of MB composites increased significantly at fiber contents exceeding 40%. The flexural moduli of AC and MB composites at fiber contents exceeding 20% were significantly greater than those of AC and MB resins without short-rod glass fibers, respectively.     

Mechanical properties of reinforced denture base resin: the effect of position and the number of woven glass fibers

This study examined the effects of the position and the number of woven glass fibers on the flexural strength, flexural modulus, and toughness of reinforced denture base resin. The woven glass fiber consisted of 1-4 laminated sheets. Chemical curing was used to polymerize three types of 4-mm-thick test specimens: fibers in compresrion, fibers in the center, and fibers in tension. Unreinforced specimens were produced as controls. A three-point flexural test was performed and the woven glass fiber content was calculated after the woven glass fiber was fired. The best results were obtained when the woven glass fiber was incorporated outside the base resin under tension, thereby increasing the flexural strength and flexural modulus. Furthermore, the denture base resin reinforced with woven glass fiber was made tougher by increasing the number of woven glass fibers incorporated into the portion under tension.     

The static strength and modulus of fiber reinforced denture base polymer.

OBJECTIVES: Partial fiber reinforcements have been employed to strengthen dentures both during repair and in the manufacturing process. The reinforcing fibers can be evenly distributed in the denture base polymer or alternatively fiber-rich phase in the denture base polymer can form a separate structure. The aim of this study was to determinate static three-point flexural strength and modulus of denture base polymer that had been reinforced with different fiber reinforcements. METHODS: The test specimens (3 x 5 x 50 mm) were made of auto-polymerized denture base polymer and reinforced with different fiber reinforcements. The test groups were: (A) no fibers; (B) non-impregnated polyethylene fibers; (C) light-polymerized monomer impregnated glass fibers; (D) porous polymer preimpregnated glass fibers and (E) light-polymerized monomer-polymer impregnated glass fibers. The fibers were oriented parallel to the long axis of the specimen and embedded into the denture base resin on the compression side (n=7) or tension side (n=7). Dry specimens were tested with three-point static flexural strength test set-up at crosshead speed of 5 mm/min. RESULTS: The statistical analysis by two-way analysis of variance showed that the brand and the location of the fiber reinforcements significantly influenced the flexural strength (p<0.0001). However, the location of the fiber reinforcements did not influence the flexural modulus (p<0.722). SIGNIFICANCE: The results suggest that impregnated and preimpregnated fibers reinforce denture base polymer more than non-impregnated fibers. Fiber reinforcements placed on the tensile side resulted in considerably higher flexural strength and flexural modulus values compared with same quantity of fibers placed on the compression side.     

玻璃纤维增强复合树脂结合界面的研究

目的：研究玻璃纤维增强复合树脂中纤维与树脂界面结合的情况。方法：将玻璃纤维分别按预处理和预浸润的不同分为六组，测试各组的挠曲强度，冲击强度，在扫描电镜和X射线电子能谱仪下，分析界面结合的好坏，结果：经过KH－550预处理的粉液比为1：1的混合物预浸润后，纤维与树脂结合最好。结论：采用合适的预处理和预浸润，有利于增加玻璃纤维增强复合树脂的机械性能。