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。     

快速液压热聚合义齿基托材料的实验研究

目的 了解快速液压热聚合义齿基托材料的力学性能。方法 采用自行研制的新型液压自控牙用树脂聚合器和常规水浴两种方法加热固化义齿基托材料，进行挠度、抗弯曲强度、弹性模量、抗冲击强度及硬度的对比分折。结果 快速液压热聚合义齿基托材料的力学性能与水浴法相比无显著性差异，但可以明显缩短热处理时间且全过程自动完成。结论 快速新型液压自控牙用树脂聚合器简化了义齿制作的操作过程，明显缩短了热处理时间，可以准确快速制作出理想的义齿。     

义齿基托沾石膏二种热处理方法情况的比较

目的:比较两种热处理方法义齿基托组织面沾石膏情况.方法:取同样的石膏模型完成基托蜡型,同等条件下去蜡,不涂分离剂充填塑料,分组用二种热处理方法进行热处理,比较基托沾石膏情况.结果:传统水浴热处理的基托均沾有厚薄不等的石膏,而液压式热处理的基托均不沾石膏.结论:采用液压式热处理器热处理可以省去涂分离剂步骤,且基托组织面不沾石膏.     

快速水式液压热聚合义齿基托材料力学性能的研究

目的：了解快速液压热聚合义齿基托材料的力学性能。方法：采用自行最新研制的新型水式液压自控牙用树脂聚合器、常规水浴法及气压式多功能牙用树脂聚合器3种方法加热固化义齿基托材料，进行挠度、抗弯曲强度、弹性模量、抗冲击强度及硬度的对比分析。结果：快速液压热聚合义齿基托材料的力学性能与水浴法及气压热聚合者相比无显著性差异，同样可以明显缩短热处理时间且全过程自动完成。结论：快速新型液压自控牙用树脂聚合器简化了义齿制作的操作过程，明显缩短了热处理时间，完全可以准确快速制作出理想的义齿。     

快速自控热处理塑料制作义齿新工艺—临床应用研究

介绍一种快速自控热处理塑料制作义齿的新工艺，该新工艺系采用高压、高温密闭水浴热聚合器．小件修复体可在石膏模型上直接徐塑热凝塑料成形，不装盒；大基托、全口义齿按常规装盒，不上压榨器，直接置于聚合器中，以０．４～０．６ＭＰａ，１２０℃水浴热处理５～１０ｍｉｎ，可使热塑性塑料完全聚合，材料性能达到质量要求。该聚合器还可用于处理热固化复合树脂或自凝塑料，热处理过程自动控制，节能，无蒸气污染。     

塑料基托的显微激光应力分析

作者应用显微激光分析仪测试了基板塑料在不同固化和结构条件下的应力水平。结果表明:塑料在水浴热聚及气压聚合化方法之间其应力水平无统计学差异。加入卡环丝会使应力集中在金属丝周围造成高应力状态。使用砂石磨改基托时引起的振动,以及用锤击型盒法出盒造成的冲击等可引起基托内应力水平升高。     

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.     

加压固化法对全口基托适合度的影响

目的:探索用普通热凝树脂在注压法条件下制作出机械性能及适合度更好的试件及基托。方法:用热凝塑料,分别按传统水浴法及注压固化法制作试件及上半口义齿基托,与BPS专用树脂材料在注压条件下制作的试件及基托,进行抗弯强度、表面硬度及基托适合度测试。采用SPSS12ForWindows统计软件进行组间t检验。结果:热凝树脂采用注压法聚合成型与采用传统水浴法聚合的试件,在抗弯强度和表面硬度上有显著差异(P<0.05)。上半口基托在A、B、D、E点上的距离差异显著(P<0.05)。结论:普通热凝树脂通过注压法聚合成型,在表面硬度、抗弯强度及基托适合度上均有所提高。     

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。     

两种热处理义齿基托的物理性能研究

长期的临床实践中 ,由于塑料在聚合过程中受多方面因素影响 ,基托时常出现气泡。为了克服气泡的产生 ,人们分析种种产生气泡的原因并加以预防 ,但仍难以保证基托不产生气泡。为此 ,我们自 1997年开始医工结合研究 ,成功采用液压式热处理器进行义齿热处理 ,有效控制塑料聚合过程中气泡的产生。现将物理性能测试结果报告如下 :1　材料和方法1.1　实验材料本实验所用牙托水由上海第二医科大学医药材料厂生产 ,牙托粉由上海齿科材料厂生产。1.2　实验方法　　按厂家推荐的粉液比调和牙托粉与牙托水 ,至面团期充填型盒 ,然后分别用常规水浴法 (I…     

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。     

Impact properties of acrylic denture base resin. 2. Effect of temperature and residual monomer on impact characteristics

The temperature dependence of the impact strength, resilience, and toughness of the acrylic denture base resins on temperature changes was examined by using a modified impact testing machine. In addition, the creep properties and the residual monomer of their resins were measured; and considering these properties, the impact characteristics of the denture base resins were discussed. With an increase in temperature, the impact properties of all the acrylic denture base resins tested decreased. Furthermore, there was an adequate correlation between the impact characteristics and the amount of the residual monomer. The coefficient of correlation was 0.92 for the impact strength, -0.95 for the resilience and 0.94 for the toughness. For the cold cured acrylic resins, both elastic moduli obtained by the impact test and by the creep test increased obviously according to an increase in the time which elapsed after polymerization.     

Flexural strength of rebased denture polymers

The properties of denture base and reline resins may be affected by daily changes between room temperature and mouth temperature. The purpose of the study was to evaluate the effect of thermocycling on the flexural strength of the relined denture base polymer with reline resin. Three denture base resins, three hard reline resins and their combinations were tested. Fourteen specimens, 65x10x2.5 mm, were fabricated for each material. Polymer combination specimens were made using 1.5 mm hard reline resin on 1.0 mm cured denture base resins. Half of the specimens were stored for 50+/-2 h in distilled water at 37 degrees C, while the other half were thermocycled for 20 000 cycles between 4 and 60 degrees C. Three point bending tests were conducted on a universal testing machine at a cross-head speed of 0.5 cm/s. The flexural strengths were measured and a statistical analysis was performed on the data using three-way ANOVA (P<0.05). The results showed that the flexural strength of relined denture base polymer was significantly higher than that of hard reline polymer. Thermocycling did not affect the flexural strength of the relined denture base polymers, whereas the denture base polymer and reline polymer alone showed a decrease in strength after thermocycling.     

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.     

Dynamic mechanical properties of hard, direct denture reline resins

STATEMENT OF PROBLEM: Dynamic mechanical properties of hard, direct reline resins are important factors in the clinical success of dentures. However, little information is available on the nature of these properties. PURPOSE: This study evaluated the dynamic mechanical properties of a variety of hard, direct reline resins: (1) visible light-polymerized, powder-liquid type, (2) visible light-polymerized, paste-type, (3) autopolymerized, powder-liquid type, as classified by component composition and mode of polymerization activation, namely, type of delivery system, and (4) heat-polymerized denture base materials. MATERIAL AND METHODS: The dynamic mechanical analysis (DMA) of 8 commercial hard denture reline materials (HDR) (2 visible light-polymerized, powder-liquid type, 4 visible light-polymerized, paste-type, and 2 autopolymerized, powder-liquid type), and 2 heat-polymerized denture base materials was obtained at a frequency of 1 Hz at 37 degrees C. Five specimens of each material, 40.0 x 7.0 x 2.0 mm, were made to measure the elastic (storage) (E') and inelastic (loss) (E') moduli, and loss tangent (tan delta). These parameters were compared with MANOVA and Student-Newman-Keuls test (alpha =.05). RESULTS: The E' values of 3 visible light-polymerized, paste-type reline resins were significantly higher than those of the other 5 reline resins. However, the E' values of all reline resins were significantly lower than those of the 2 heat-polymerized denture base resins. Except for 1 autopolymerized reliner, all reline materials had significantly lower E' than the heat-polymerized denture base resins. The tan delta values of all but 1 visible light- and autopolymerized reliners were significantly higher than those of the heat-polymerized denture base materials. CONCLUSIONS: Three visible light-polymerized, paste-type reline resins showed greater stiffness than the visible light- or autopolymerized, powder-liquid type reline resins. However, all of the hard, direct reline resins, including the 3 paste-type materials, exhibited greater flexibility compared to the heat-polymerized denture base resins.     

齿科树脂基托热压注塑成型机的研制及应用

目的 研制齿科树脂基托热压注塑盛开时机,探讨应用前景。方法 由压机部件、液压部件和电器控制部件三部分组成齿科树脂基托热压注塑成型机,运用ＰＭＭＡ试量口嘶托。结果 使用ＰＭＭＡ树脂由齿科树脂基托注塑成型机制成全口义齿基托。结论 齿科树脂基托热压注塑成型机方便实用,初步观察义齿基托制品性能良好。     

微波聚合法对义齿基托树脂力学性能影响的研究

目的研究微波聚合方法对义齿基托树脂力学性能的影响。方法分别用微波聚合和水浴聚合方法制作63.0 mm×10.0 mm×2.5 mm的树脂试样各10个,经过10 000次冷热循环后,用电子万能试验机测量其弯曲强度和弯曲模量;同法制作同样规格的树脂试样各10个,用电子万能试验机测量其拉伸强度。结果微波法和水浴法制作的义齿基托树脂弯曲强度分别为（76.18±15.56）MPa和（73.06±13.01）MPa,差异无统计学意义（t=0.534 2,P〉0.05）;弯曲模量分别为（1 709.10±98.76）MPa和（1 699.21±90.23）MPa,差异无统计学意义（t=0.568 2,P〉0.05）;拉伸强度分别为（42.19±1.12）MPa和（44.35±1.22）MPa,差异无统计学意义（t=0.627 4,P〉0.05）。结论微波聚合方法制作的义齿基托树脂力学性能与水浴法制作的相当,但微波法聚合时间较水浴法明显缩短。     

Evaluation of mechanical and thermal properties of commonly used denture base resins.

PURPOSE: The purpose of this investigation was to evaluate and compare the mechanical and thermal properties of 6 commonly used polymethyl methacrylate denture base resins. MATERIALS AND METHODS: Sorption, solubility, color stability, adaptation, flexural stiffness, and hardness were assessed to determine compliance with ADA Specification No. 12. Thermal assessments were performed using differential scanning calorimetry and dynamic mechanical analysis. Results were assessed using statistical and observational analyses. RESULTS: All materials satisfied ADA requirements for sorption, solubility, and color stability. Adaptation testing indicated that microwave-activated systems provided better adaptation to associated casts than conventional heat-activated resins. According to flexural testing results, microwaveable resins were relatively stiff, while rubber-modified resins were more flexible. Differential scanning calorimetry indicated that microwave-activated systems were more completely polymerized than conventional heat-activated materials. CONCLUSION: The microwaveable resins displayed better adaptation, greater stiffness, and greater surface hardness than other denture base resins included in this investigation. Elastomeric toughening agents yielded decreased stiffness, decreased surface hardness, and decreased glass transition temperatures.     

Development of visible-light cured FRP denture

Acrylic denture may be fractured easily because it has a relatively poor resistance to stresses of impact, and the thick acrylic denture base also uncomforted to denture wearers. In this study, for improvement of the mechanical properties, the FRP is applied to the denture base, and try to make a thin denture base. Using the visible light-curing system, the laboratory fabrication time is saved dramatically. To develop the visible light-cured FRP denture base, with various combination of matrix resins and reinforcements, the physical properties of FRP plates were investigated first. From the results of the bending test, hardness test, and manipulation considering, the sateen weave's glasscloth was choose as the reinforcement of the prepreg. The matrix resin of Bis-GMA/UDMA/3G at 48/48/4 wt% was determined. The 3 plies glasscloth included FRP plate is 0.8 mm thickness has the maximum bending strength about 50 kgf/mm2, which is about 5 times larger than that of acrylic resin. Succeeding the study of above, the FRP denture base was fabricated by using the 0.8 mm thickness 3 plies included prepreg. This repreg is manufactured in sheet form beforehand, which is ease to manipulate at laboratory. By using the visible light curing system, it is only taken 10 min. to make a FRP denture base. The following procedures of fabricating a FRP denture is the same as metalplate denture. The visible-light cured FRP denture has some advantages such as accuracy of fit, ease of fabrication and manipulation, and only 0.8 mm thickness but has superior strength.