SY-1和MDX4-4210硅橡胶热老化性能试验

目的 对比SY-1和MDX4-4210硅橡胶的热老化性能。方法 在相同条件下对两种硅橡胶材料进行了热老化试验,对其老化性能加以评价。结果 热老化后,SY-1硅橡胶的扯断强度性能变化百分比与MDX4-4210硅橡胶无显著差异(P>0.05);SY-1硅橡胶的邵氏硬度、扯断伸长率、永久变形率(3min后)、撕裂强度的性能变化百分比优于MDX4-4210硅橡胶(P<0.01)。结论 SY-1硅橡胶热老化性能略优于MDX4-4210硅橡胶,热老化性能可以满足作为面部软组织缺损赝复材料的要求。     

SY-28、SY-20和MDX4-4210硅橡胶机械性能的对比测定

目的:对比SY-28、SY-20和MDX4-4210硅橡胶的机械性能。方法:以MDX4-4210硅橡胶为对照,对SY-28、SY-20硅橡胶扯断强度、扯断伸长率、永久变形率(3分钟)、撕裂强度、硬度(邵氏A)进行测试,对其机械性能加以评价,并进行统计学分析。结果:SY-28硅橡胶的扯断伸长率、撕裂强度和邵氏硬度优于MDX4-4210硅橡胶;扯断强度和永久变形率与之相似。SY-20硅橡胶的邵氏硬度优于MDX4-4210硅橡胶;扯断强度、扯断伸长率、永久变形率和撕裂强度与之相似。结论:①SY-28、SY-20硅橡胶可以满足颌面软组织缺损赝复材料的机械性能要求。②在硬度上,SY-28硅橡胶适合用于耳、鼻等缺损的修复;SY-20硅橡胶适合颌面部软组织缺损的修复。③应用硅橡胶并用技术弥补现有硅橡胶的性能缺陷,可以获得更适合临床应用的硅橡胶赝复材料。     

低邵氏硬度SY复合型硅橡胶的配方筛选

目的 :得到邵氏硬度分别为 18、2 0、2 2的复合型硅橡胶赝复材料 ,以满足特定缺损部位的赝复体硬度要求。方法 :质量比均匀混合 ,加入适量的混合交联剂固化并加工成长方形试样。测试其邵氏硬度 ,选出硬度值最接近 18、2 0、2 2的三种硅橡胶试样 ,确定相应的配方比例。结果 :当SY复合型硅橡胶邵氏硬度为 18.1± 3 .6、19.9± 4.1、2 2 .0± 2 .8时 ,SY 1硅橡胶和C型硅橡胶的配方比例依次为 76∶2 4、78∶2 2、84∶16。结论 :按照适当比例进行SY 1硅橡胶和C型硅橡胶的并用 ,可以得到邵氏硬度分别为 18、2 0、2 2的低邵氏硬度SY复合型硅橡胶赝复材料 ,满足不同的赝复临床需要     

高邵氏硬度SY复合型硅橡胶的配方筛选

目的:研制邵氏硬度分别为26、28、30的复合型硅橡胶赝复材料,以满足特定缺损部位的赝复体硬度要求。方法:质量比均匀混合,加入适量的混合交联剂固化并加工成长方形试样。测试其邵氏硬度,选出硬度值最接近26、28、30的3种硅橡胶试样,确定相应的配方比例。结果:当SY复合型硅橡胶邵氏硬度为26.1±3.2、28.0±2.9、30.1±3.5时,SY-1和B硅橡胶的配方比例依次为82:18、79:21、76:24。结论:按照适当比例进行SY-1和B硅橡胶的并用,可以得到邵氏硬度为26、28、30的高邵氏硬度SY复合型硅橡胶赝复材料。     

SY-28、SY-20和MDX4-4210硅橡胶吸水率和溶解率的对比测定

目的:对比SY-28、SY-20和MDX4-4210硅橡胶的吸水率和溶解率。方法:在相同条件下,测定SY-28、SY-20和MDX4-4210硅橡胶的吸水率、溶解率,对其物理性能加以评价,并进行统计学分析。结果:SY-28硅橡胶第8周的吸水率为3.112%,与MDX4-4210硅橡胶(3.012%)相似;SY-28硅橡胶第8周的溶解率为0.4401%,高于MDX4-4210硅橡胶(0.3179%)。SY-20硅橡胶第8周的吸水率和溶解率分别为3.501%,0.4756%,均高于MDX4-4210硅橡胶的吸水率和溶解率。结论:SY-28、SY-20硅橡胶能够满足赝复材料的临床要求,但仍需对材料及配方进行修改与完善,降低其吸水率和溶解率。     

SY-1及MDX4-4210硅橡胶吸水率溶解率撕裂强度的对比测定

目的：对比SY－1和MDX4－4210硅橡胶的吸水率，溶解率，撕裂强度性能。方法：在相同条件下对两种硅橡胶材料进行吸水率，溶解率及撕裂强度测定，对其进行t检验分析。结果：SY－1硅橡胶吸水率，溶解率性能差于MDX4－4210硅橡胶，撕裂强度优于MDX4－4210硅橡胶。结论：SY－1硅橡胶的撕裂强度符合作为颌面部软组织缺损的赝复材料要求；作为与液体有密切接触的赝复材料时，其吸水率，溶解率性能尚须进一步改进。     

热氧老化作用对SY-28、SY-20和MDX4-4210硅橡胶机械性能的影响

目的:评估热氧老化作用对SY-28、SY-20和MDX4-4210硅橡胶机械性能的影响。方法:按照国家标准,对SY-28、SY-20和MDX4-4210硅橡胶热氧老化前后的扯断强度、扯断伸长率、永久变形率(3min)、撕裂强度、硬度(邵氏A)进行测试,对其老化性能加以评价,并进行统计学分析。结果:SY-28硅橡胶的扯断伸长率、永久变形率(3min)、邵氏硬度优于MDX4-4210硅橡胶;扯断强度、撕裂强度与之相似。SY-20硅橡胶的扯断强度、永久变形率(3min)、邵氏硬度优于MDX4-4210硅橡胶;扯断伸长率与之相似,撕裂强度差于MDX4-4210硅橡胶。结论:SY-28和SY-20硅橡胶机械性能优良,同时具有良好的抗热氧老化性能,可以满足作为颌面软组织缺损赝复材料的要求。     

不同SY-1硅橡胶被覆厚度对三明治式硅橡胶结构拉伸性能的影响

目的：比较不同SY-1硅橡胶被覆厚度的三明治硅橡胶结构的拉伸性能。方法：在相同条件下对表面被覆SY-1厚度分别为0mm,1mm,1.5mm,2mm的三明治式硅橡胶试件进行拉伸强度、扯断伸长率的测定,并对结果进行统计学分析。结果：被覆1mm SY-1硅橡胶的试件与单纯的GP-084泡沫硅橡胶试件拉伸强度及扯断伸长率的差异有显著性（p〈0.05）;被覆1.5mm SY-1试件与被覆1mm的SY-1试件的拉伸强度的差异无显著性（p〉0.05）,但是扯断伸长率的差异具有显著性（p〈0.05）;被覆2mmSY-1试件与被覆1mm SY-1试件的拉伸强度及扯断伸长率的差异有显著性（p〈0.05）。结论：由SY-1硅橡胶和GP-084泡沫硅橡胶组成的三明治式结构可以明显增加泡沫硅橡胶较低的拉伸强度和扯断伸长率。     

油画类颜料配色的MDX4-4210硅橡胶皮肤斑贴试验

目的 :研究油画类赝复配色颜料 -硅橡胶复合体导致皮肤出现变态反应的能力。方法 :制备油画类颜料配色的MDX4-4 2 10硅橡胶试样 ,将其放于两侧前臂曲面 ,医用胶布片密封和固定试样 ,分别在 2 4h、48h、72h去除胶布和试样 ,观察、记录结果 ,并进行评价。结果 :全部皮肤测试部位在第 2 4h、48h、72h时的皮肤表面均未出现各种形式的皮肤变态反应 ,标准分级均为阴性。结论 :油画类赝复配色颜料 -硅橡胶复合体具有良好的皮肤接触安全性     

SY-1硅橡胶固化前后颜色的变化

目的:研究SY-1硅橡胶固化前后颜色的变化,为临床赝复体的比配色提供指导。方法:用美能达(CS-321)便携式色差仪测试SY-1硅橡胶固化前后的色度值L*、a*、b*,根据色差公式△E=[(△L)2 (△a)2 (△b)2]1/2,计算出其固化前后的色差。结果:根据对10个样本固化前后色度值的测定,得出SY-1硅橡胶固化前后色差为1.92±0.23。结论:SY-1硅橡胶固化前后材料颜色发生了变化,主要表现为肉眼可识别明度增加。     

医用硅橡胶套管的口镜柄对预防创伤性口角炎的效果

目的研究陕用硅橡胶套管的口镜对口角黏膜的保护作用。方法分别选取来我院行上颌第二磨牙烤瓷冠修复的患者600名,实验组300名,对照组300名。实验组采用口镜柄套用医用硅橡胶材料的口镜,对照组之间采用常舰口镜,术后第2天复诊检查口角黏膜损伤情况。结果采用改良口镜治疗的患者口角黏膜损伤仅占1．6％,而常规口镜治疗的黏膜损伤占5．3％,实验组和对照组之间有统计学差异（P〈0．05）。结论口镜柄套有医用硅橡胶管可以有效保护口角黏膜。     

臭氧老化作用对SY-1硅橡胶机械性能的影响

目的：评估臭氧老化作用对SY－1硅橡胶物理性能，机械性能的影响，方法：按国家标准要求对SY－1硅橡胶臭氧化前后硬度（邵氏－A），扯断强度，扯断伸长率和撕裂强度进行测试，并进行统计学分析。结果：经臭氧化老化作用处理，硬度差异显著（P＝0．0082），扯断强度，扯断伸长率，永久变形和撕裂强度老化前后无显著差异（P＞0．05）。结论：SY－1硅橡胶物理机械性能优良，同时具有良好的抗臭氧老化性能。     

硅橡胶印模与口内扫描印模在口腔临床教学中的比较

目的：通过本科实习医师制取硅橡胶印模及数字化口内扫描印模的教学实践,对比2种取模方式的操作时间、学习的难易程度和患者的接受程度等。方法：6名本科实习医师分别作为医师和患者进行取模练习,由专人记录操作时间,并用视觉模拟量表（VAS）记录患者满意度。采用SPSS 23.0软件包对数据进行统计学分析。结果：在取模时间、学习总时间、总体舒适度方面,硅橡胶印模优于口内扫描印模,两者之间有显著差异(P<0.05)。结论：采用硅橡胶取模,患者的就诊体验更好。采用口内扫描印模技术,需要医师具有更熟练的操作技能。应用角色扮演的方式,实习医师可以更好地学习到不同取模方式的操作要点及注意事项。     

Effects of sample hardness on human chewing force: a model study using silicone rubber

This study aims to clarify the effects of sample hardness on chewing force of humans. Silicone rubber was chosen as a food model, and three silicone rubber samples of varying hardness were chewed between the upper and lower incisors or molars in a natural way. Chewing force, contact area between a specimen and teeth, and pressure applied into the specimen were dynamically measured with a multiple-point sheet sensor. The multiple-point measurement revealed that a harder sample evoked higher peak force, longer duration, higher impulse, and higher active pressure values, whereas the chewing cycle and time to peak were not affected by sample hardness. The contact area between the sample and teeth decreased for the harder sample during incisor chewing. The peak force and force-related parameters, contact area, time to peak and bite force duration showed higher values for molar bites than for incisor bites, while the chewing cycle was similar in both cases. The measurement with the sheet sensor system clearly indicated that sample hardness modified chewing force of humans. We hypothesise that the effect of sample hardness is mainly mediated by mechanoreceptors in the periodontal ligament.     

Interactions of pigments and opacifiers on color stability of MDX4-4210/type A maxillofacial elastomers subjected to artificial aging

STATEMENT OF PROBLEM: The color instability and degradation of maxillofacial elastomers limit the function and cosmetic quality of facial prostheses. PURPOSE: The purpose of this study was to measure the interactions of oil pigments plus dry earth opacifiers at 5%, 10%, and 15% by volume in stabilizing the color of MDX4-4210/type A silicone elastomers before and after artificial aging. MATERIAL AND METHODS: In the first part of the study, each of 5 opacifiers (Georgia kaolin powder neutral, kaolin powder calcined, Artskin white, dry pigment titanium (Ti) white, or Ti white artists' oil color) at 10% concentrations were combined with each of 5 oil pigment types (no pigment, cadmium-barium red deep, yellow ochre, burnt sienna, or a mixture of the 3 pigments), for a total of 25 experimental groups of elastomers. In the second part of the study, 50 experimental groups of elastomers were made by combining 1 of 5 opacifiers at 5% and 15% concentrations with 1 of 5 oil pigments as in Part 1. Five specimens of each elastomer were tested, for a total of 375 specimens. In each part of the study, all specimens were aged in an artificial aging chamber. CIE L*a*b* values were measured by a spectrophotometer. The color differences (DeltaE*) were subjected to repeated-measures analysis of variance. Mean values were compared by Tukey-Kramer intervals (alpha = .05). RESULTS: In Part 1, when the opacifiers were tested at 10% concentration, Ti white oil color had the most color change, and dry pigment Ti white had the least; all other opacifiers were not significantly different from each other. In Part 2, at 5%, Ti white oil color had the most color change; all other opacifiers were not significantly different from the others. At 15%, Ti white oil color again had the most color change, followed by Artskin white, kaolin powder calcined, and Georgia kaolin; Ti white dry earth pigment had the least color change. Overall, 5% Artskin white had less color change than the 15%, whereas 15% dry pigment Ti white had less color change than the 5% (P < .001). The 5% and 15% of other opacifiers were not significantly different. CONCLUSIONS: At all 3 concentrations, oil pigments mixed with opacifiers helped protect the MDX4-4210/type A silicone elastomer from color degradation over time. Dry pigment Ti white remained the most color stable over time, followed by the pigments mixed with kaolin powder calcined, Georgia kaolin, Artskin white, and Ti white artists' oil color.     

The Effect of Aging by Thermal Cycling and Mechanical Brushing on Resilient Denture Liner Hardness and Roughness

Purpose: The purpose of this study was to investigate the effects of aging on resilient denture liners. The aging effects were produced by using thermal cycling and mechanical brushing and were quantified as changes to surface hardness and roughness of resilient denture liners.
Material and Methods: A plasticized acrylic resin (Dentuflex) and two silicone-based (Molloplast-B, Sofreliner MS) resilient denture liners were examined. Pre- and post-test roughness and hardness measurements were recorded using a Surfcorder SE 1700 and Shore A durometer Teclock GS-709, respectively. Sixty specimens were manufactured; half were subjected to 3000 cycles in the thermal cycler (5 and 55°C). The remaining specimens received 30,000 strokes applied by a mechanical brushing machine followed by 3000 thermal cycles. Representative specimens from each group were observed under scanning electron microscope (SEM). Data were examined by multiple ANOVA, split-plot analysis, and Tukey test (α= 0.05).
Results: Shore A hardness values for Dentuflex, Molloplast-B, and Sofreliner MS soft liners were different from each other ( p < 0.05) before (79 ± 2.9; 40 ± 1.4; 33 ± 0.7) and after (80 ± 3.1; 40 ± 1; 34 ± 0.9) thermocycling. The surface roughness (in μm) of the same soft liner materials was significantly different ( p < 0.05) at the start (2.2 ± 0.4; 1.6 ± 0.6; 0.2 ± 0.1) but it was not different ( p > 0.05) after tooth brushing (1.7 ± 0.3; 1.7 ± 0.4; 1.9 ± 0.8) or thermocycling (1.6 ± 0.5; 1.6 ± 0.6; 1.5 ± 0.5)
Conclusion: Thermal cycling promoted increased hardness for Sofreliner MS and Dentuflex. Mechanical brushing promoted wear abrasion in Sofreliner MS and Dentuflex materials. Molloplast-B experienced no deleterious effects from either of the tests.     

氩等离子体对国产SY-1硅橡胶吸水率、溶解率的影响

目的：观察氩低温等离子体对国产SY-1硅橡胶吸水率、溶解率的影响。方法：将固化好的硅橡胶试样分组,按照不同工作参数组合对处理组SY-1硅橡胶试样进行氩气低温等离子体处理,处理后测定各组的吸水率、溶解率。结果：工作参数为1T,50W,1．5min时,材料吸水率降低显著;各参数下材料的溶解率未得到改善。结论：本实验条件下氩等离子体处理可以改善材料的吸水率,不能降低其溶解率。