3种方法表面处理后钯银合金与聚合瓷结合性能比较

目的比较3种方法表面处理后钯银合金与聚合瓷的结合性能,研究能够有效提高钯银合金与聚合瓷结合性能的方法。方法制作18个钯银合金试件,平均分为3组,喷砂组常规表面喷砂处理,酸蚀组用质量分数4．9％氢氟酸行表面处理,硅涂层组用Roeatec—plus粉行表面处理。测定3组试件与聚合瓷的剪切粘接强度,并用扫描电镜观察3组断裂面形貌。结果喷砂组、酸蚀组、硅涂层组的剪切粘接强度分别为（11．93±1．01）Mpa、（18．39±1．70）Mpa、（23．75±1．11）Mpa,差异有统计学意义（P〈0．05）。结论3种表面处理方法中,硅涂层方法的钯银合金与聚合瓷结合性能最好。     

不同口腔修复材料与天然牙耐磨性能的比较

目的：通过体外模拟实验对几种口腔修复材料与天然牙釉质的磨耗性能进行对比研究并探讨其机制.方法：（1）将钴铬合金,纯钛,氧化锆陶瓷,Ceramage聚合瓷制成符合规格的试件.（2）将上颌第一前磨牙磨改,作为对照组.（3）将滑石瓷制做圆盘状,作为与试件及天然牙对磨的材料.（4）所有实验均在人工唾液环境中加载测试.（5）SPSS17.0软件进行统计学处理,对磨耗后的试件进行磨痕形貌的观察.结果：（1）纯钛的磨耗量与牙釉质最接近.钴铬合金与氧化锆陶瓷无统计学意义（P＞0.05）,其余各组之间均有统计学意义（P＞0.05）.磨耗后质量损失量的大小顺序为纯钛＞牙釉质＞ Ceramage聚合瓷＞氧化锆陶瓷＞钴铬合金.（2）钴铬合金：磨粒磨损,同时伴有粘着磨损.纯钛：以粘着磨耗为主,伴有磨粒磨耗.氧化锆陶瓷：磨粒磨损.Ceramage聚合瓷：主要是磨粒磨损和粘着磨损,伴有疲劳磨损.天然牙：粘着磨损和磨粒磨损.结论：（1）纯钛的耐磨性低于牙釉质但与牙釉质最为相近,是一种良好的修复材料.（2）钴铬合金与氧化锆陶瓷的耐磨性能接近,均可对天然牙釉质造成过度磨耗.（3）修复材料的耐磨性能受其微观结构的影响.     

两种不同氧化钇含量的牙科氧化锆瓷与牙釉质的摩擦磨损性能

目的：通过体外模拟实验考察两种不同氧化钇含量的牙科氧化锆瓷与天然牙釉质的摩擦磨损性能。方法：选择两种不同氧化钇含量的牙科氧化锆瓷UpceraST（3mo1％Y2O3-ZrO2）与Upcera TT（3mo1％Y20-ZrO2＋8mo1％Y2O3-ZrO2）在微摩擦磨损试验机上,人工唾液润滑下与天然牙釉质进行摩擦磨损实验。两种氧化锆瓷表面分别采用抛光和打磨处理。用激光共聚焦显微镜测量牙釉质磨斑宽度,扫描电子显微镜观察氧化锆瓷及牙釉质磨斑微观形貌。采用配对t检验进行统计学分析。结果：牙釉质与氧化钇含量相对较低的UpceraST对磨的磨斑宽度：抛光组474．2±18．0μm,打磨组581．5±32．7Win;牙釉质与氧化钇含量相对较高的UpceraTT对磨的磨斑宽度：抛光组476．8±33．7μm,打磨组591．3±55．7μm。不同氧化钇含量的氧化锆瓷采用相同的表面处理方式对牙釉质的磨耗无统计学差异（P〉0．05）。牙釉质磨斑宽度在不同表面处理组间差异有统计学意义（P〈0．01）：牙釉质与抛光氧化锆瓷对磨的磨斑宽度值小于打磨组。结论：两种不同氧化钇含量的氧化锆瓷摩擦磨损性能相似;氧化锆瓷表面抛光可避免牙釉质过度磨损。与抛光氧化锆瓷对磨,牙釉质的磨损类型主要是疲劳磨损;与打磨氧化锆瓷对磨,牙釉质的磨损类型主要是磨粒磨损。提示临床在对充填体或修复体调磨后应进行抛光处理,以避免造成对颌天然牙的过度磨损。     

4种齿科金属材料与牙釉质耐磨损性能的研究

目的：研究齿科金属材料耐磨损性能及与牙釉质耐磨损性能的匹配情况。方法：使用MMV-1立式万能摩擦磨损试验机,以天然牙釉质为对照,滑石瓷为对磨物,在人工唾液,37℃试验工况下,对口腔修复用金钯合金、银钯合金、纯钛,镍铬合金进行二体摩擦磨损试验。采用扫描电镜观察表面磨损形貌,x线衍射能谱仪分析磨屑成分,显微硬度仪测试表面硬度,电子天平得出磨损量。结果：4种金属材料自身磨损量和对磨物磨损量与牙釉质均有统计学差异（P〈0.05）,其中金钯合金及对磨物与牙釉质及对磨物最接近。金属试样使滑石瓷体积磨损量与其硬度值间存在显著性正相关关系（相关系数r=0.95,P〈0.05）。金属材料的磨损机制主要是黏着磨损和磨粒磨损,牙釉质的磨损机制主要是疲劳磨损。结论：金钯合金耐磨损性能与牙釉质最相匹配,作为固定修复材料比镍铬合金、纯钛、银钯合金更具有优越性。     

拟与纯钛匹配的RG实验瓷的热力学性能测试

目的：评价自行研制的拟与纯钛匹配的RG低熔实验瓷的热力学性能。方法：采用Setaram-TGDTA92型综合分析仪,对RG实验牙本质瓷粉和遮色瓷粉进行差热分析,以确定其玻璃相转化温度。分别将RG牙本质瓷和遮色瓷作制成25mm×10mm×8mm大小的试件,各2个;铸造规格为04mm×25mm的纯钛试件2个。用Dilatometry-Dil402NET2SCH热膨胀系数测定仪,测定这3组试件的热膨胀系数。结果：遮色瓷和牙本质瓷的玻璃相转化温度分别为470℃和460℃。遮色瓷、牙本质瓷和纯钛的热膨胀系数分别为6．28±0．06×10^-6℃、7．69±0．08×10^-6／℃和10．00±0．100×10^-6／℃。结论：实验瓷与纯钛热力学性能基本匹配。     

弱光启动固化对后牙树脂聚合收缩和表面硬度的影响

目的探讨弱光启动固化对三种临床常用的光同化后牙树脂（EcuSphere—Carat，EC；Fihek P60，P60；Tetric Ceram HB．HB）聚合收缩和表面硬度的影响。方法将树脂充填入直径0．7cm、高0．4cm的圆柱状容器中．每种树脂实验组和对照组各10个样本．采用扫描电镜测量树脂样本与充填容器的边缘裂隙宽度，评价弱光启动对聚合体积收缩的影响；同法制备样本，每种树脂实验组和对照组各7个样本．采用显微硬度计测量两种固化方式处理的样本表面的维氏硬度．探讨弱光启动固化对树脂表面硬度的影响．结果EC、P60、HB三种树脂传统光固化后边缘裂隙宽度分别为（15．32±1．78）μm、（15．72±1．97）μm和（16．14±1．74）μm，差异无统计学意义（P〉0．05）；弱光启动固化后的边缘裂隙宽度分别（14．83±3．34）μm、（13．64±1．92）μm、（14．18±2．01）μm，弱光启动固化后的边缘裂隙宽度减小＋差异有统计学意义（P〈0．05）。树脂表面硬度传统光固化后分别为（116．76±12．00）MPa、（159．14±5．90）MPa、（119．59±5．00）MPa：弱光启动固化后分别为（109．74±5．77）MPa、（154．81±3．99）MPa、（114．11±6．42）MPa，表面硬度较传统光固化低，差异有统计学意义（P〈0．05）。结论弱光启动固化模式能有效降低后牙树脂的聚合收缩．但树脂的表面硬度有所下降．三种树脂中P60的表面硬度最高。     

6种不同修复材料与天然牙牙釉质摩擦、磨耗性能的比较

目的：通过体外摩擦、磨耗实验,比较临床常用的陶瓷材料、多种合金及天然牙釉质的摩擦、磨耗性能,为临床上选择与对颌牙磨耗性能相近的修复材料,更好地保护对颌牙提供一定的实验依据。方法：将陶瓷、纯钛、钛合金、镍铬合金、金钯合金、银汞合金和近期拔除的成人下颌第三磨牙的釉质平面,与滑石瓷磨头磨耗机上对磨。耐磨性能的评定采用称重法。用针一盘磨损试验仪测定各种材料的滑动摩擦系数。应用SPSS11．5软件包进行统计学处理．对各试件、天然牙的质量损失量进行统计学分析,对比分析摩擦系数。结果：单位面积的磨损量以天然牙釉质最小,但与瓷块、银汞合金、金钯合金无显著性差异（P〉0．05）,与其余各组均有显著性差异（P〈0．01）;纯钛最大,与其余各组均有显著性差异（P〈0．01）,镍铬合金、金钯合金与其余各组均有显著性差异（P〈0．01）。瓷块的摩擦系数稳定在0．68,银汞合金的摩擦系数为0．12,金钯合金的摩擦系数为0．11,镍铬合金为0.41,纯钛为0.38,钛合金为0．48,天然牙釉质为0．65。结论：6种修复材料的耐磨性均比天然牙釉质差．纯钛的耐磨性最小,钛合金及镍铬合金、金钯合金次之,陶瓷的耐磨性最大。     

口腔修复材料对牙本质的磨损性能的研究

目的:研究牙色材料与天然牙本质之间磨损性能的匹配情况.方法:以牙本质为研究对象,以实验组高度抛光的聚合瓷、玻璃陶瓷、氧化锆为摩擦剂,模拟口腔环境,利用微摩擦磨损实验机,研究牙本质与不同材料之间的摩擦磨损性能.采用扫描电镜观察表面形貌,粗糙度仪测粗糙度,维氏硬度仪测表面硬度,电子天平测磨损量.结果:牙本质与3种材料粗糙度近似(P＞0.05),硬度小于3种材料(P＜0.05).牙本质与3种材料分别对磨后材料的磨损量大于牙本质对照组的磨损量(P＜0.05),牙尖牙本质的磨损量与3种材料及牙本质的硬度值呈显著正相关关系(r =0.840).其中聚合瓷组的牙本质磨损量与对照组最接近.结论:不同材料对牙本质均会造成不同程度的磨损,聚合瓷具有与牙本质相近的耐磨性能.     

金钯合金进行纳米类金刚石镀膜后表面性能的实验研究

目的旨在通过类金刚石镀膜的方法改善金钯合金的耐磨性、硬度。方法制作6个金钯合金试件,在常温下通过射频辉光放电的方法分别镀覆300纳米、500纳米类金刚石镀膜,对镀膜后金钯合金表面的摩擦系数、电化学腐蚀电位及维氏硬度进行测试,并同标准试件进行比较。结果300纳米镀膜金钯合金耐磨性高于500纳米镀膜;随着镀膜厚度的增加,耐腐蚀性有增加的趋势;对维氏硬度的均值进行t检验,镀膜300纳米金钯合金维氏硬度高于500纳米试件及标准件（P〈0.001）。结论对金钯合金表面进行类金刚石镀膜处理是改善其表面理化特性的一种尝试。     

反复熔铸对钯基烤瓷合金力学性能影响的研究

目的:探讨反复熔铸对钯基烤瓷合金力学性能的影响。方法:钯基烤瓷合金在不添加新合金的情况下,经过1～3次单纯反复熔铸后,用拉伸实验对各代试件的拉伸强度、0.2%屈服强度、延伸率进行比较;用弯曲实验对各代试件的弯曲强度、弯曲模量进行比较;用硬度实验对各代试件的维氏硬度值进行比较。结果:经不同次数熔铸的钯基烤瓷合金试件的拉伸强度、0.2%屈服强度、延伸率和显微硬度的差别无统计学意义;各代试件的弯曲强度随着熔铸次数的增加而下降(P<0.05)。结论:钯基烤瓷合金经1～3次单纯反复熔铸后,拉伸性能、显微硬度未发生下降,但弯曲性能发生下降。     

老年恒牙、年轻恒牙及乳牙釉质磨损性能的体外对比研究

目的探讨并比较各个年龄组人牙釉质磨损行为的异同.方法采用老年恒牙、年轻恒牙及乳牙各8个釉质样本,经体外模拟摩擦试验测得其磨损量,通过测量硬度和断裂韧性以及分析磨斑形貌和釉质中Ca、P、Si元素含量等揭示釉质的摩擦磨损机制.结果老年恒牙、年轻恒牙、乳牙牙釉质磨损量分别为(2.40±1.10)×10-12 m3、(3.50±1.83)×10-12 m3、(4.86±2.49)×10-12 m3,其中老年恒牙磨损明显小于乳牙(P＜0.05),年轻恒牙与乳牙、老年恒牙与年轻恒牙磨损量间差异无显著性(P＞0.05),但三者在机械性能和磨损特征方面均有所不同.结论各年龄组人牙釉质与陶瓷牙对摩时,主要发生磨粒磨损和断裂磨损,各类牙釉质超微结构的差异决定了其抗磨性能的不同.人牙釉质的硬度和断裂韧性测量值与磨损量无对应关系.     

Wear evaluation of porcelain opposing gold, composite resin, and enamel

STATEMENT OF PROBLEM: When porcelain surfaces oppose gold and composite resin restorations as well as enamel, wear resistance and abrasiveness of the porcelain are clinical concerns to maintain the occlusal relationship. However, there is limited information on comparison of mutual wear rates when these materials oppose in 2-body and 3-body conditions. PURPOSE: The purpose of this study was to evaluate mutual wear rates of dental porcelain and opposing materials, including a gold alloy, a composite resin, and human enamel, using an in vitro wear test. MATERIAL AND METHODS: Mutual wear between high-fusing dental porcelain (Ceramco II) disks (9 x 5-mm thick) with a rough or smooth surface and opposing styli made of gold alloy, composite resin, or human enamel was evaluated in 2-body and 3-body conditions using a wear simulator (n=8). Wear depths (microm) of porcelain disks were determined using a profilometer. Wear depths (microm) of the opposing materials were obtained by converting the worn surface areas into wear depths using image-analysis software. All data were statistically analyzed by 3-way analysis of variance and Bonferroni-Dunn test (alpha=.05). The worn surfaces were observed by scanning electron microscope (SEM). RESULTS: The wear values for porcelain opposing composite resin or enamel in the 2-body condition were significantly greater than those in the 3-body condition, regardless of the surface condition of the porcelain (P<.001). For stylus specimens, all values in the 2-body condition were significantly greater than those in the 3-body condition, regardless of the surface condition of the opposing porcelain (P<.001). These results are supported by SEM observations of worn surfaces. CONCLUSION: The results of this study suggest that mutual wear rates, when porcelain opposes gold, composite resin, and enamel, are influenced by 2-body and 3-body wear conditions.     

Wear of enamel and veneering ceramics after laboratory and chairside finishing procedures

PURPOSE: This in vitro study compared the wear of enamel against 3 types of ceramics with high esthetic potential (designed for layering techniques): feldspathic porcelain (Creation), aluminous porcelain (Vitadur alpha), and low-fusing glass (Duceram-LFC). Laboratory finishing (glazing/polishing) and chairside polishing with a Dialite kit were simulated to compare their respective effects on wear. METHODS: Tooth-material specimen pairs were placed in an artificial mouth using closed-loop servohydraulics. Constant masticatory parameters (13.5 N occlusal force, 0.62 mm lateral excursion; 0.23 second cuspal contact time) were maintained for 300, 000 cycles at a rate of 4 Hz. The occlusal surface of each pair was mapped and digitally recorded before and after each masticatory test. Quantitative changes were measured in terms of depth and volume of wear. Quantitative wear characteristics were assessed by SEM. RESULTS: Significant differences were observed (2-factor ANOVA, P <.05). Duceram-LFC generated increased volume loss of enamel (0.197 mm(3)) compared with Creation (0.135 mm(3)) and Vitadur alpha (0.153 mm(3)). Creation exhibited the lowest ceramic wear and lowest combined volume loss (0.260 mm(3); the sum of the data for enamel and the opposing material) compared with Duceram-LFC (0.363 mm(3)) and Vitadur alpha (0.333 mm(3)). The most significant differences among materials were observed in volume loss, not in depth of wear. For all 3 ceramic systems, qualitative SEM evaluation revealed an abrasive type of wear. Wear characteristics of chairside polished specimens were similar to those of laboratory finished specimens (glazed and polished). CONCLUSION: Duceram-LFC was the most abrasive ceramic for the antagonistic tooth. Creation ceramic was the least abrasive material and most resistant to wear. Defects, brittleness, and the possibly insufficient toughness of LFC may explain its increased abrasiveness. Laboratory and chairside finishing procedures generated similar results.     

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目的 对比钯银(Pd-Ag)合金和钴铬(Co-Cr)合金的机械性能及金瓷结合强度,为临床提供基础数据.方法 本研究于2010年12月至2011年2月在中国科学院金属研究所分析测试部完成.常规方法制作Pd-Ag合金和Co-Cr合金试件,首先对二者进行硬度测试和拉伸测试,然后分别行常规烤瓷并利用水平剪切法进行界面结合强度测试,利用扫描电镜(SEM)和能谱分析技术对金瓷界面进行观察和元素分析.结果 硬度:Pd-Ag合金为(187.44±3.64) HV,低于Co-Cr合金(361.53±10.15)HV(P＜ 0.05).拉伸测试:Pd-Ag合金的屈服强度为(467.50±14.40)MPa,小于Co-Cr合金(568.10± 30.94) MPa (P＜ 0.05);Pd-Ag合金的抗拉强度为(631.83±15.51)MPa,小于Co-Cr合金(758.73±25.85) MPa(P＜ 0.05).剪切强度:Pd-Ag合金为(57.67±5.44) MPa,Co-Cr合金为(26.80±4.95)MPa,差异有统计学意义(P＜0.05).扫描电镜观察和能谱分析显示:2种合金与瓷之间均存在过渡层,合金与瓷层间存在元素的相互渗透.结论Pd-Ag合金的机械性能低于Co-Cr合金,但可满足临床需要;而Pd-Ag合金的金瓷结合强度高于Co-Cr合金.     

Wear Testing of Composite, Gold, Porcelain, and Enamel Opposing a Removable Cobalt–Chromium Partial Denture Alloy

Purpose: Eighty percent of all removable partial denture (RPD) frameworks are fabricated from cobalt–chromium (Co–Cr) alloys. The advantages of this material include low density and high modulus of elasticity, hardness, and strength. Hardness is of particular concern when related to excessive wear of natural teeth or restorative materials. The purpose of this study was to compare the differences in localized wear among enamel, composite, gold, and porcelain by a Co–Cr alloy RPD.
Materials and Methods: Thirty-two polished specimens were prepared and positioned in an acrylic-filled custom fixture for testing. Upon optical examination, the highly polished surfaces of the specimens were scratch-free. They were mounted into a water bath fixture and subjected to 250,000 cycles in a wear simulator equipped with a conical Co–Cr stylus specially fabricated to produce localized wear. A posttest was generated, and the profiles were fitted and evaluated using software. The total volume loss and depth of the wear facet on each specimen were analyzed using ANOVA and Fisher's PLSD test.
Results: Volume loss (mm³) was as follows: composite, 0.110; gold, 0.021; enamel, 0.008; porcelain, 0.006. The maximum depths (μm) were: composite, 92; gold, 22; enamel, 13; porcelain, 17. Resin composite had significantly higher values ( p < 0.0001) of volumetric loss and maximum depth than the other materials. No significant differences were detected among volumetric loss and maximum depth values for gold, enamel, and porcelain.
Conclusions: Significant differences for mean wear volume loss and maximum depth were found between composite and gold, enamel, and porcelain. Enamel proved to be wear resistant to the Co–Cr alloy. Clinical implications: porcelain and gold appear to be good options for occlusal surfaces opposing a Co–Cr alloy; however, the test composite was not found to be a recommended option.     

In vitro investigation of the wear of human enamel by dental porcelain

STATEMENT OF PROBLEM: Metal ceramic systems are advocated when both esthetics and strength are required. A major drawback to many porcelains is their wear and destruction of opposing natural dentition. PURPOSE: This study evaluated the wear of enamel opposing 1 traditional and 2 recently introduced low-fusing feldspathic dental porcelains. MATERIAL AND METHODS: Six blocks of Ceramco II, Finesse, and Omega 900 feldspathic porcelain materials were fabricated and fired according to manufacturer recommendations. Porcelain blocks were polished through 0.25 microm diamond polishing paste. Thirty-six enamel specimens were obtained and milled to a 2 mm (+0.5 mm) diameter. Enamel specimens were attached to an offset cam motor operating at 60 Hz. Enamel specimens were in constant contact with the stationary porcelain blocks under a load of 600 g and traversed a distance of 8 mm. Diameter and height of enamel specimens were measured at times of 0, 6, 12, 24, and 48 hours and subsequent determination of enamel volume loss recorded. Profilometric surface roughness of the ceramic blocks was also measured for the corresponding times. RESULTS: Statistical analysis revealed that both Finesse and Omega 900 feldspathic porcelains caused significantly less enamel volume loss when compared with Ceramco II porcelain at all time intervals. Surface roughness revealed no consistent significant differences among porcelains. CONCLUSION: Both Finesse and Omega 900 porcelains were not as destructive to human tooth structure as Ceramco II porcelain. These results suggest an advantage of the new, lower-fusing porcelains in conditions where natural dentition wear is a concern.     

Wear evaluation of the human enamel opposing different Y-TZP dental ceramics and other porcelains

PurposeThis study examined the wear resistance of human enamel and feldspathic porcelain after simulated mastication against 3 zirconia ceramics, heat-pressed ceramic and conventional feldspathic porcelain.Materials and methodsHuman teeth and feldspathic porcelain cusp were tested against ceramic discs. 5 brands were tested – 3 monolithic zirconia, Prettau, Lava, and Rainbow, one lithium disilicate, IPS e.max Press, and one feldspathic porcelain, Vita-Omega 900. The surface was polished using a 600 grit and 1200 grit SiC paper. Each group was loaded for 300,000 cycles in a chewing simulator. The wear resistance was analyzed by measuring the volume of substance lost. The wear surfaces were observed by scanning electron microscopy to determine the wear characteristics.ResultsVita-Omega 900 led to the greatest amount of enamel wears followed by IPS e.max Press, Prettau, Lava and Rainbow. There was a significant difference between Vita-Omega 900 and IPS e.max Press (p < 0.05). The wear values for human enamel were significantly greater than those for feldspathic porcelain, regardless of the surface roughness of the ceramic specimens (p < 0.05).ConclusionThe wear behaviour of human enamel and feldspathic porcelain varies according to the type of substrate materials. On the other hand, 3 zirconia ceramics caused less wear in the abrader than the conventional ceramic.Clinical significanceDental professionals should be aware of the wear effect of dental restorations on the opposing teeth or restorations. The amount of enamel wear was highest in feldspathic porcelains whereas zirconia ceramics caused less wear on the opposing teeth.