义齿基托树脂的力学性能研究

通过测试４种商品义齿基托树脂的弯曲强度，冲击强度，挠度及弹性模量，评价了采用可见光，热和微波聚合的基托树脂的力学性能，结果显示：热处理效果优于光和自凝处理，在热处理中，水热优于热压，热压优于微波加热。     

4种义齿基托树脂力学性能比较

目的 :比较 4种义齿基托树脂的力学性能 ,为临床选择材料提供指导。方法 :按临床制作义齿的步骤制备试样 ,在材料试验机上测定材料的冲击强度、弯曲强度、弹性模量和布氏硬度 ,描绘弯曲试验的应力 应变曲线 ,并对断面进行显微分析。结果 :4种义齿基托树脂 (上海珊瑚、山西长治、Luciton199、Meliodent)的冲击强度分别为 (9.94± 2 .2 5)kJ/m2 、(6.55± 1.85)kJ/m2 、(13 .76± 4.3 1)kJ/m2 、(13 .70± 3 .71)kJ/m2 ,弯曲强度分别为 (75.2 7± 3 .2 4)MPa、(78.88± 7.66)MPa、(80 .47± 3 .2 7)MPa、(76.72± 3 .14 )MPa ,弹性模量分别为 (3 .0 8± 0 .15)GPa、(2 .96± 0 .10 )GPa、(2 .63± 0 .11)GPa、(2 .56± 0 .12 )GPa ,布氏硬度分别为(2 4.15± 1.3 4 )kg/mm2 、(2 3 .43± 1.65)kg/mm2 、(2 0 .86± 1.2 6)kg/mm2 、(18.49± 1.71)kg/mm2 。结论 :4种基托树脂材料相比 ,”上海珊瑚”和”山西长治”基托树脂硬而脆 ,Luciton 199基托树脂硬而强 ,Meliodent基托树脂硬而韧     

不同聚合方法对基托树脂挠曲强度影响的实验研究

目的在实验室条件下比较2种义齿基托树脂经过4种聚合方法处理后基托树脂的挠曲强度,为临床选择适宜的聚合方法提供依据。方法用金属模具制备相同尺寸的蜡型96个,失蜡后使用2种品牌的义齿基托树脂填胶,用4种方法进行热处理使其固化,用万能力学实验机检测基托树脂的挠曲强度．用双因素方差分析和多重比较进行统计学处理。结果两种基托树脂的挠曲强度具有显著差异（P〈0.01）,不同聚合方法间基托树脂的挠曲强度除电热法与一组水浴方法存在显著差异外．其余组间无显著差异。结论基托树脂的挠曲强度和材料的性能有关,不同聚合方法对基托树脂的挠曲强度没有显著影响。     

义齿清洁剂对树脂基托颜色的影响

目的：研究常用义齿清洁剂对树脂基托颜色的影响。方法：用四种常用的义齿清洁剂处理四种国内常用的基托树脂，用CS5电脑配色系统检测树脂颜色的变化。结果：不同树脂的颜色受不同清洁剂的影响不同，洁美清洁剂对登士柏热凝和日进热凝树脂的白度增加和色差较大；0.02％NaClO对日进自凝树脂的白度增加和色差较大；0.0125％NaClO和0.02％NaClO对上海自凝树脂的白度增加和色差较大。结论：洁美清洁剂对登士柏热凝和日进热凝树脂的颜色改变较明显，NaClO对日进自凝树脂和上海自凝树脂的颜色改变较明显。     

微波和水浴聚合法对树脂基托义齿精度影响的研究

目的：研究微波和水浴聚合法对树脂基托义齿精度的影响。方法：用微波法和水浴法分别制作上颌全口义齿,然后在上颌第二磨牙远中部位切断义齿基托与标准模型,用数字显微镜测量上颌全口义齿基托组织面与标准模型之间共5个部位的间隙。结果：微波法制作的义齿5个部位的精度分别为：（243±85）μm、（98±38）μm、（88±23）μm、（93±20）μm、（185±50）μm,水浴法分别为：（240±55）μm、（94±28）μm、（91±37）μm、（103±35）μm、（209±36）μm,两种方法在相同点处差别无统计学意义。结论：微波法和水浴法制作的义齿精度无显著性差异,但微波法聚合时间较水浴法大为缩短。     

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。     

国产高强度义齿基托树脂的临床应用

聚甲基丙烯酸甲酯,由于其操作简便,自问世以来,一直是口腔制作义齿基托的主要材料。但由于聚甲基丙烯酸甲酯材料韧性较低,脆性较大,制作义齿容易折断,给患者增加了不便之处。为解决这个问题,国外70年代开始对聚甲基丙烯酸甲酯进行改性研究,80年代末美国Dentsply公司首先在市场推出,俗称“不碎基托”。但其价格昂贵,国内一般患者难以接受。因此,广东省化学纤维研究所从1992年开始研究引入液体增韧剂—低分子量长链液体橡胶,制成聚丁二烯多甲基丙烯酸酯(PDDPMA)—环氧二甲基丙烯酸酯(EPDMA)(Polybuta—diene Polymethacrylates—Epoxydimet—hacrylate)接枝共聚物作为抗冲击改性剂,对聚甲基丙烯酸甲酯进行改性,研制出国产高强度基托材料。笔者从1994年初与其合作,同年12月至1996年12月在临床试用高强度基托材料。经二年临床观察,结果如下:     

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。     

注塑法进行附着体义齿树脂基托的制作

附着体义齿由于兼有固定义齿和可摘义齿的优点,是口腔修复的重要组成部分.目前,附着体义齿可摘部分树脂基托的制作主要采用传统装盒、填胶、热处理的方法进行,在装盒过程中,很容易造成已制作好的固定部分发生变形或破折,严重影响附着体义齿的修复效果.作者向大家介绍一种采用注塑法进行义齿树脂基托制作的方法,通过对传统工艺进行改良,不仅避免了以上现象的发生,同时,工艺流程更加简单.     

聚酰亚胺共混改性增强义齿基托材料的力学性能研究

目的 研究聚酰亚胺共混改性聚甲基丙烯酸甲酯义齿基托树脂的力学性能。方法 对自行合成的聚酰亚胺（添加质量百分比分别为0,0.4%,0.6%,0.8%,1%）与PMMA义齿基托树脂共混得到的改性基托树脂进行三点弯曲强度试验、断面形态扫描电镜观察和冷热循环试验。结果 聚酰亚胺改性基托树脂抗弯强度在适当共混配比（0.6%）下可达（99.84±3.07）MPa,显著高于未改性树脂的抗弯强度（87.95±5.01）MPa,提高13.5%（P<0.05）。经过冷热循环后其增强效果依然显著（P<0.05）。结论 添加一定量的聚酰亚胺共混改性PMMA基托树脂能获得理想的增强效果。     

改性纳米氧化铈对义齿树脂基托机械性能的影响

目的:研究经硬脂酸改性后的纳米CeO₂对义齿树脂基托机械性能的影响。方法:将改性纳米颗粒按照质量比分别为1%、2%、3%、4%和5%的添加量添加到义齿基托材料(PMMA)的单体中,制成不同浓度的纳米齿复合材料,制成标准试件。对每组试件冲击强度,弯曲强度等指标进行检测,并与未添加纳米颗粒组比较,将最终数据进行统计分析。结果:经硬脂酸改性后的纳米氧化铈能够提高树脂基托的机械性能,所测试指标都呈现先增大后减小的趋势。其中添加比例为3%时纳米复合材料的综合性能达到最佳状态,其冲击强度、弯曲强度和弯曲模量分别为(4.186±0.149) J/cm²、(88.865±2.345) MPa和(1.539±0.096) GPa(P<0.05)。结论:在义齿基托材料单体中加入不同浓度的纳米氧化铈颗粒可以提高传统义齿基托的冲击强度,弯曲强度等机械性能,从而可以获得品质优良的纳米义齿复合材料。     

Effect of Surface Treatment on the Flexural Strength of Denture Base Resin and Tensile Strength of Autopolymerizing Silicone Based Denture Liner Bonded to Denture Base Resin: An In Vitro Study

Silicone based denture liners are superior to acrylic based denture liners but it has a problem of failure of adhesion with the denture base. To evaluate the effect on the tensile bond strength of silicone based liner and flexural strength of denture base resin when the latter is treated with different chemical etchants prior to the application of the resilient liner. Rectangular specimens of heat cured PMMA (65 × 10 × 3.3 mm³) for flexural strength and (10 × 10 × 40 mm³) for tensile strength were fabricated and divided into four subgroups each. One subgroup of each type acted as a control and the rest were subjected to surface treatment with acetone for 30 s, MMA monomer for 180 s, methylene chloride for 15 s, respectively. Silicone based denture liner was processed between 2 PMMA specimens (10 × 10 × 40 mm³) in the space provided by a spacer, thermocycled (5^–55°C) for 500 cycles and then their tensile strength measurements and flexural strength measurements were done. 180 s of MMA monomer treatment was found to be most effective in improving the bonding between the liner and denture base resin as well as producing the lowest decrease in flexural strength of denture base resin. Chemical treatment of denture base resin improves the bond strength of denture liner but it also decreases the flexural strength of denture base. So careful selection of chemical etchant should be done so as to produce minimum decrease in flexural strength of denture base resin.     

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．     

可见光固化基托树脂研究

研究了可见光固化基托树脂的基质树脂、多功能单体和光引发体系的合成工艺以及粘度调整剂、基托树脂、处理剂、空气遮蔽剂的制备工艺;讨论了基质树脂结构、交联剂结构、光引发体系、光照时间以及不同光源照射等因素对光固化基托树脂物理性能的影响;还讨论了光固化基托树脂的色泽稳定性以及空气遮蔽剂、气泡对光固化基托树脂表面形态的影响。     

Effect of Surface Preparation on the Failure Load of a Highly Filled Composite Resin Bonded to a Denture Base Resin

Purpose: The purpose of this study was to evaluate the effect of the surface preparation on the maximum fracture load value of a highly filled gingival shade composite resin bonded to a denture base resin. Materials and Methods: Block specimens were prepared from a heat‐processed denture base resin and divided into five groups. The flat surfaces of the specimens were abraded with 400‐grit silicon carbide paper, then prepared in one of the following ways: (1) without preparation (group 1); (2) application of silane coupling agent (group 2); (3) application of dichloromethane (group 3); (4) application of dichloromethane following the silane coupling agent (group 4); or (5) tribochemical silica coating (group 5). A highly filled gingival shade composite resin was applied (area Ø= 5 mm) and polymerized with a light polymerizing unit. Specimens made entirely of heat‐processed denture base resin were also fabricated as references (group 6). The halves of the specimens of groups 4, 5, and 6 were thermocycled up to 10,000 times in water between 5°C and 55°C with a 1‐minute dwell time at each temperature. Shear testing was performed in a universal testing machine at a crosshead speed of 1 mm/min, and the maximum fracture load values were determined (n = 10). Results: The maximum fracture load values of the highly filled gingival shade composite resin bonded to the denture base resin for all preparation groups were significantly enhanced before thermocycling (p < 0.05). Group 5 exhibited the greatest fracture load value, followed by group 4, compared to the other groups (p < 0.05), however, the fracture load values significantly decreased for these groups after thermocycling (p < 0.05), whereas the fracture load value of group 6 did not decrease (p > 0.05). Conclusions: Tribochemical silica coating and the application of dichloromethane after the silane coupling agent were effective surface preparations for the bonding of a highly filled gingival shade composite resin to a denture base resin, however, the bond durability of these treatments may be insufficient.     

Comparative Evaluation of Tensile Bond Strength between Silicon Soft Liners and Processed Denture Base Resin Conditioned by Three Modes of Surface Treatment: An Invitro Study

Soft denture liners act as a cushion for the denture bearing mucosa through even distribution of functional load, avoiding local stress concentrations and improving retention of dentures there by providing comfort to the patient. The objective of the present study was to compare and evaluate the tensile bond strengths of silicone-based soft lining materials (Ufi Gel P and GC Reline soft) with different surface pre treatments of heat cure PMMA denture base acrylic resin. Stainless steel dies measuring 40 mm in length; 10 mm in width and 10 mm in height (40 × 10 × 10) were machined to prepare standardized for the polymethyl methacrylate resin blocks. Stainless steel dies (spacer for resilient liner) measuring 3 mm thick; 10 mm long and 10 mm wide were prepared as spacers to ensure uniformity of the soft liner being tested. Two types of Addition silicone-based soft lining materials (room temperature polymerised soft lining materials (RTPSLM): Ufi Gel P and GC Reline soft) were selected. Ufi Gel P (VOCO, Germany), GC Reline soft (GC America) are resilient, chairside vinyl polysiloxane denture reliners of two different manufacturers. A total of 80 test samples were prepared of which 40 specimens were prepared for Group A (Ufi Gel P) and 40 specimens for Group B (GC Reline soft). In these groups, based on Pre-treatment of acrylic resin specimens each group was subdivided into four sub groups of 10 samples each. Sub-group I—without any surface treatment. Sub-group II—sand blasted Sub-group III—treated with Methyl Methacrylate monomer Sub-group IV-treated with chemical etchant Acetone. The results were statistically analysed by Kruscal Wallis test, Mann–Whitney U test, and Independent t test. The specimens treated with MMA monomer wetting showed superior and significant bond strength than those obtained by other surface treatments. The samples belonging to subgroups of GC Reline soft exhibit superior tensile bond strength than subgroups of Ufi Gel P. The modes of failure of all specimens were mostly adhesive in nature. Surface pre treatments by chemical means improved the bond strength between the silicone liners and denture base.