烧结次数对金属烤瓷修复体剩瓷率的影响

目的：用一种新指标－－剩瓷率研究烧结次数对金属烧瓷修结合强度的影响。方法：采用Mackert于1988年设计的恒的恒应力弯曲装置，应用能谱分析仪，测量金瓷样本烧结1－9次的剩瓷率，分析烧结次数对金属结合强度的影响。结论：t检验分析，金瓷修复体烧结3次，剩瓷率明显降低，烧结3－9次，剩瓷率无明显的改变。结论：金瓷修复体烧结次数应尽可能控制在3次以内。     

金瓷混合涂层烧结温度对镍铬合金与瓷结合强度的影响

目的:比较不同烧结温度所获得的金瓷结合强度有无差异并探讨其机制。方法:在镍铬合金预氧化表面和遮色瓷之间涂一层blendgoldneu金泥糊剂,在不同的温度下进行烧结,用剪切试验测量金瓷结合强度,并用电子探针观察界面结合情况及界面元素的扩散情况。结果:在820、890、960℃3种温度下烧结涂层时,前2种烧结温度所获得的金瓷结合强度无明显差异,而960℃温度下烧结涂层所获得的金瓷结合强度明显高于820、890℃条件下烧结涂层及用传统方法所获得的金瓷结合强度。结论:涂层烧结温度对金瓷结合强度的影响显著,在一定范围内,涂层烧结温度越高金瓷结合强度的改善越明显。     

烤瓷熔附金属制作工艺与金瓷结合强度的研究进展

PFM修复体的瓷折裂，大多涉及金瓷界面结合不良。贵金属表面预氧化可增强金瓷结合强度，而非贵金属表面因易形成过厚氧化膜而不宜在大气中高温氧化。瓷层过厚或厚度不均匀促使金瓷界面产生裂纹。瓷的烧结条件等影响因素目前尚存在不同观点。研究金瓷结合的方法有结合强度检测、扫描电镜分析界面等。本文对近年来研究不同制作条件影响金瓷结合强度的国内外文献作一回顾。     

纳米介质影响纯钛金瓷结合强度的实验研究

目的：研究纳米介质对纯钛金瓷结合强度的影响。方法：用纯钛制成金属棒以及金属片,随机分为实验组和对照组。实验组在金属试件上瓷前涂附纳米二氧化钛介质;金属棒与专用瓷粉烧结生成金瓷棒盘试件用于测定金瓷结合强度;金属片与瓷粉烧结形成金瓷复合体,分别观察金瓷界面的形貌及元素分布情况。结果：涂附纳米过渡性介质的实验组,金瓷结合强度明显高于对照组（P〈0.01）。结论：纳米过渡性介质有改善纯钛金瓷结合强度的作用。     

预遮色瓷涂布厚度对金瓷结合强度的影响

目的：通过比较在高低温烧结瓷组中试件的金瓷结合强度,观察涂布不同厚度预遮色瓷对金瓷结合强度的影响。方法：按ISO9693文件要求制作统一试件,高温烧结瓷组及低温烧结瓷组中均分别制作6件无预遮色瓷、6件涂布较薄厚度预遮色瓷和6件涂布较厚厚度预遮色瓷的试件,用三点弯曲测试方法测试初始裂瓷压力,比较不同烧结温度瓷粉涂布不同厚度预遮色瓷对金瓷结合强度的影响。采用SPSS10.0软件包进行描述性统计和SNK方差检验。结果：在低温烧结瓷组中,涂布较薄厚度预遮色瓷组金瓷结合的强度显著大于涂布较厚厚度预遮色瓷组（P〈0.05）。二组涂布预遮色瓷试件的金瓷结合强度均大于不涂预遮色瓷组,但均无显著差异（P〉0.05）。在高温烧结瓷组中,涂布不同厚度预遮色瓷对金瓷结合强度无显著影响（P〉0.05）。结论：低温和高温烧结瓷组的试件在预遮色瓷烧结后金瓷结合强度均明显增加,预遮色瓷涂布厚度对金瓷结合强度有一定影响。     

预氧化对镍铬烤瓷合金金瓷界面的影响

目的:研究预氧化处理对Ni-Cr烤瓷合金金瓷界面的影响。方法:失蜡法铸造尺寸为25mm×3mm×0.5mm的金属片16个,随机分为两组,每组8个。组1进行预氧化处理,组2不做处理。每组各取6个试件,采用三点弯曲法测试金瓷结合强度,剩余2个试样进行扫描电子显微分析(SEM)和能谱分析(EDS),考察金瓷界面形貌与成分分布状况。结果:测得未预氧化组金瓷结合强度为45.91±8.22MPa,预氧化组为41.92±3.55MPa。单因素方差分析(P=0.256>0.05)表明两者差异无显著性。结论:预氧化处理有利于金瓷界面生成均匀一致的氧化膜,促进扩散作用,提高金瓷界面的稳定性和结合强度。但预氧化也可能导致金瓷界面出现裂纹、孔洞、疏松等缺陷,反而降低金瓷结合强度。     

纳米过渡性介质对新型牙用烤瓷支架钴铬合金金瓷结合强度影响的研究

目的：研究纳米过渡性介质对新型牙用烤瓷支架钴铬合金（简称DA9-4合金）金瓷结合强度的影响。方法：用DA9-4合金制成金属棒以及金属片,并在金属试件上瓷前涂附纳米二氧化硅和纳米金介质2种不同的过渡性介质;金属棒与VMK95瓷粉烧结生成金瓷棒盘试件用于测定金瓷结合强度;金属片与VMK95瓷粉烧结形成金瓷复合体,分别观察金瓷界面的形貌及元素分布情况。结果：涂附纳米过渡性介质后的金瓷结合强度明显高于对照组（P〈0.01）。结论：纳米过渡性介质有改善新型牙用烤瓷支架钴铬合金金瓷结合强度的作用。     

除气和预氧化对纯钛金瓷结合强度的影响

目的研究上瓷前纯钛除气和预氧化对其金瓷结合强度的影响。方法用ISO9693[1]规定的三点弯曲测试法测定A组（除气＋预氧化）、B组（无热处理）试件的金瓷结合强度,用电镜扫描和X线衍射分析金瓷界面。结果金瓷结合强度：A组32.61±5.62Mpa,B组24.19±3.57Mpa,两者之间具有显著性差异（P=0.001）;扫描电镜（SEM）：A组金瓷之间过渡层约65μm,金瓷结合紧密。B组金瓷间过渡层平均约35μm,可见孔洞和裂隙。x射线衍射（EDS）：两组金瓷界面附近的主要元素均为O、Si、Ti、Sn,A组Ti在界面呈单纯扩散曲线。B组Ti在界面呈不规则扩散。结论纯钛除气和预氧化后能获得较高的金瓷结合强度,大于ISO规定的25Mpa,能满足临床要求;无热处理试件金瓷结合强度较低,小于25Mpa,不能满足临床要求。     

热循环和机械循环对切削Ti2448和纯钛金瓷结合强度的影响

目的 研究热循环和机械循环对切削Ti2448和纯钛金瓷结合强度的影响。方法 按照ISO 9693的标准分别制作纯钛和Ti2448烤瓷试件各30个,每种试件均随机分为3组,A组为对照组,在37 ℃水浴中保存24 h;B组和C组在5~55 ℃水浴中热循环3 000次,在每一个温度下保持60 s,然后采用载荷50 N、频率4 Hz,机械循环20 000次（B组）或40 000次（C组）。采用三点弯曲实验测试试件的金瓷结合强度,通过扫描电镜和能谱分析金瓷剥脱面和金瓷结合界面的显微结构和成分组成,对结果进行两因素方差分析和Tukey检验。结果 A组中,纯钛试件的金瓷结合强度（29.21 MPa±2.20 MPa）明显小于Ti2448试件（44.86 MPa±1.75 MPa）（P<0.01）;纯钛试件和Ti2448试件中,C组与A组之间均有统计学差异（P<0.01）。扫描电镜和能谱分析结果显示,Ti2448瓷剥脱面有明显的瓷残留,而纯钛瓷剥脱面无明显瓷残留。结论 热循环和机械循环处理降低了Ti2448和纯钛的金瓷结合强度。     

热处理对含钛镍铬合金、镍铬合金金瓷结合强度的影响

目的：探讨热处理对含钛镍铬（Ni?Cr?Ti）合金、镍铬（Ni?Cr）合金金瓷结合强度的影响和两种合金的金瓷界面特征。方法执行ISO9693标准,采用三点弯曲试验分别测定经减压热处理或未经热处理的含钛镍铬合金、镍铬合金的金瓷结合强度。运用扫描电镜和X射线能谱进行金瓷界面分析。结果金瓷结合强度分析结果显示：Ni?Cr?Ti减压热处理组为（38.04±3.79）MPa ,Ni?Cr?Ti无热处理组为（32.17±4.00）MPa ,Ni?Cr减压热处理组为（36.32±7.41）MPa,Ni?Cr无热处理组为（31.75±2.77）MPa。镍铬合金和含钛镍铬合金金瓷结合强度差异无统计学意义（F=0.500,P=0.484）,但两种合金减压热处理后的金瓷结合强度均大于无热处理组（F=11.973,P=0.001）。扫描电镜和X线衍射结果显示,两种合金减压热处理组金属与瓷之间结合紧密,无热处理组金属与瓷之间可见裂纹及气泡。结论含钛镍铬合金与镍铬合金的金瓷结合强度接近,通过减压热处理可提高两种合金金瓷结合强度。     

Shear bond strength of techniques for bonding esthetic veneers to metal

STATEMENT OF PROBLEM: New composites with improved qualities have been introduced to the dental profession as alternatives to porcelain. There is concern about the strength and reliability of new metal-resin bonding systems when these composites are used as esthetic veneers over metal frameworks. PURPOSE: This in vitro study compared the shear bond strength of 2 metal-resin bonding techniques with the bond strength of conventional porcelain fused-to-metal (PFM). Effects of water storage and thermocycling were also evaluated. MATERIAL AND METHODS: Ninety disks, cast in a medium gold, high noble PFM alloy, were divided equally into 6 groups, and received 3 treatments for veneering: conventional feldspathic porcelain on 1 group, and a composite (Artglass) bonded to the metal, using 2 metal-resin bonding techniques. Specimens were tested in shear, half of them after a 24-hour dry storage at room temperature and the rest after 10-day storage in normal saline solution at 37 degrees C and thermocycling. Fractured specimens were evaluated under x10 magnification to determine the nature of failure. Statistical analysis was performed with 2-factor analysis of variance (ANOVA). RESULTS: Mean shear bond strength values before and after wet storage and thermocycling were 29.66 and 22.91 MPa for the PFM group; 21.43 and 17.92 MPa for the Siloc group; and 19.34 and 15.64 for the etched group, respectively. The PFM group exhibited significantly higher bond strength values compared with the other 2 groups (P<.001). All groups showed a significant decrease in bond strength values after wet storage and thermocycling (P<.001). CONCLUSION: Wet storage and thermocycling caused a significant decrease in shear bond strength of all specimens. Shear bond strength of conventional feldspathic PFM was significantly higher than that of the 2 metal-resin bonding techniques tested. The 2 latter techniques did not reveal any statistically significant differences.     

Shear Bond Strength Evaluation of Different Veneering Systems on Ni-Cr Alloys

PURPOSE: The aim of this study was to evaluate the shear bond strength of four esthetic veneering materials on nickel-chromium (Ni-Cr) alloy. MATERIALS AND METHODS: Forty square patterns (10 x 10 x 1.5 mm) were cast with Ni-Cr, divided equally into four groups, and received four treatments for veneering: conventional porcelain-fused-to-metal (PFM), Artglass, Targis/Vectris, and Biodent light-cured prosthodontic composite resins. After sandblasting of the cast metal surfaces with 50 micro m alumina, the composites were applied to the surfaces according to manufacturers' recommendations. Shear bond strength was determined at a crosshead speed of 0.5 mm/min. Results were analyzed statistically with Kruskal-Wallis analysis of variance and multiple comparison tests. RESULTS: Mean shear bond strength values were 34.96 MPa for PFM, 14.17 MPa for Targis/Vectris, 13.64 MPa for Artglass, and 10.56 MPa for Biodent. The PFM group exhibited significantly higher bond strength values compared with the other three groups (p < 0.001). CONCLUSION: PFM showed considerably higher shear bond strength values than the three metal-resin bonding techniques.     

两种热处理方式对激光焊接钴铬-镍铬异种合金力学性能和组织结构的影响

探讨常规热处理和烤瓷对激光焊接钴铬-镍铬异种合金力学性能和组织结构的影响,以期为异种合金的临床应用提供参考.方法将0.5 mm厚的钴铬合金和镍铬合金试件各15个从中间断开,进行激光焊接,制成30个钴铬-镍铬异种合金焊件.焊后用随机数字表将焊件随机分为3组,每组10个.对照组不做处理,热处理组焊件进行常规热处理,烤瓷组焊件进行烤瓷处理.测试3组焊件的拉伸强度和延伸率,扫描电镜观察拉伸断口,能谱分析测试3组焊件熔焊区、钴铬焊接交界区和镍铬焊接交界区元素.结果经热处理和烤瓷处理后,焊件拉伸强度分别为(537.15±43.91)MPa和(534.58±48.47)MPa,延伸率分别为(7.65±0.73)%和(7.40±0.45)%.烤瓷组拉伸断口出现明显的韧窝结构,热处理组拉伸断口表现为深而大的韧窝;钴铬侧合金成分向熔焊区和镍铬侧有一定程度的扩散,热处理组比烤瓷组扩散更明显.结论热处理和烤瓷过程均可在一定程度上改善激光焊接钴铬-镍铬异种合金焊接接头的性能,热处理对焊接接头性能的改善比烤瓷更明显.     

Sprayed opaque porcelain as a retentive surface for resin-bonded restorations

This study investigated the shear bond strength between etched enamel and 4-mm-diameter base metal castings cemented with Panavia EX. Four different methods of casting preparation were used: air abraded, salt crystals placed on the wax patterns, opaque porcelain sprayed on the metal surface, and sprayed opaque porcelain followed by a silane coupling agent. The prepared surfaces were examined before and after testing using SEM and electron dispersive analysis by x-rays. It was determined that there was no significant difference in the shear bond strength between the salt-crystal technique and the nonsilanated sprayed ceramic surfaces. The air-abraded surface was the least retentive, and the silanated opaque porcelain specimens had intermediate retention. The sprayed opaque porcelain technique seems to offer several advantages.     

The effect of surface treatments on the bond strength of a nonprecious alloy-ceramic interface

PURPOSE: The purpose of this study was to compare the effect of seven different alloy surface treatments on the bond strength of the porcelain-metal interface. MATERIALS AND METHODS: Three layers of opaque porcelain and a measured thickness of dentin porcelain were applied to nickel-chromium alloy. A tensile bond strength test was used. RESULTS: The alloy surface treatment that exhibited the highest bond strength was sandblast + surface grinding + sandblast + de-gas, whereas the alloy surface treatment that exhibited the lowest bond strength was sandblast + surface grinding + sandblast + steam cleaning + de-gas. There was a significant difference between the two methods (P < 0.05). CONCLUSION: It was concluded that de-gassing the alloy prior to porcelain application increased the bond strength and excess surface grinding of the alloy reduced bond strength; steam cleaning the alloy surface prior to de-gassing and porcelain application also significantly reduced the bond strength.     

桩核对根管治疗牙修复后强度的影响

目的　比较不同修复方法对根管治疗牙修复后强度的影响。方法　 6 0个完整拔除的人上中切牙 ,根管治疗后随机分为 5组 ,每组 12个。A组 :完整的根管治疗牙 ;B组 :根管治疗后烤瓷熔附金属 (PFM)全冠修复 ;C组 :牙体预备保留 2 0mm高的牙本质套圈 ,铸造金属桩核及PFM全冠修复 ;D组 :牙体预备无牙本质套圈 ,铸造金属桩核及PFM全冠修复 ;E组 :牙体预备保留 2 0mm高的牙本质套圈 ,Parapost预成桩、复合树脂核及PFM全冠修复。在MTS 810材料试验机上沿与牙长轴成 135度方向加载 ,测试折裂强度。结果采用方差分析。结果　牙体预备保留 2 0mm高的牙本质套圈 ,铸造金属桩核及PFM全冠修复者折裂强度最高 ,为 (1793 5 9± 387 93)N ;完整的根管治疗牙次之 ,为(146 6 6 8± 2 40 11)N ;其余 3组的折裂强度 (95 8 49± 2 86 0 2 )N、(992 98± 2 91 0 0 )N、(994 94± 2 85 0 4)N之间 ,差异无显著性。修复牙有无牙本质套圈 ,其折裂强度间差异有高度显著性 (P <0 0 1)。结论　桩核能否增强根管治疗牙的抗折裂强度与其修复设计有关 ,牙本质套圈可明显增强根管治疗牙的抗折裂能力。     

Effect of opaque porcelain application on strength of bond to silver-palladium alloys

The opaque porcelain layer for porcelain-fused-to-metal restorations is critical for success. This investigation examined opaque porcelain application using one- and two-layer techniques with respect to their effect on the strength of bond to three silver-palladium alloys. There were no significant differences in the flexural bond strengths of the three alloys for the one- and two-layer opaque application techniques. With respect to bond strength, these results afford flexibility in the choice of the one- or two-layer techniques.     

硅涂层，MEPS, 固位微球对镍铬合 金与Artglass剪切粘结强度的影响

目的：观察硅涂层,含硫代磷酰基团偶联剂及固位微球对ＮｉＣｒ合金与Ａｒｔｇｌａｓｓ的剪切粘结强度的影响。方法：将３２个ＮｉＣｒ合金试件分为４组,每组８个试件分别按上述三种方法处理表面,单纯喷砂组作对照,然后与Ａｒｔｇａｌｓｓ树脂粘结,测定其剪切强度。结果：与对照组相比,三种表面处理方法均显著提高了ＮｉＣｒ合金与复合树脂的剪切强度（Ｐ＜０．０１）,且固位微球组获得最大的剪切强度,而硅涂层与偶联剂组强度上无明显差别（Ｐ＞０．０５）。结论：三种表面处理方法所得强度均可为临床应用所接受,但各有优缺点,临床应用时应综合考虑。     

不同表面处理方法对陶瓷托槽与不同瓷修复体粘结强度影响的研究

目的:评价不同瓷修复体试件经过3种表面处理方法后与陶瓷托槽粘结强度的关系。方法:钴铬烤瓷、铸瓷、锆瓷及聚合瓷4类试件经过喷砂(SB)、氢氟酸酸蚀(HFA)、喷砂+酸蚀(SB+HFA)处理后表面涂布硅烷偶联剂(SCA),再粘接陶瓷托槽,经37 ℃恒温水浴24 h 后检测粘接强度(SBS),扫描电镜观察托槽粘接前修复体表面的粗糙度及去除后修复体表面粘接剂残留情况。结果:钴铬烤瓷、铸瓷和聚合瓷试件的抗剪切强度分别与锆瓷试件比较差异有统计学意义(P＜0.05);钴铬烤瓷和铸瓷试件的抗剪强度比较差异无统计学意义。扫描电镜结果显示4组试件表面粗糙度都有明显增加。而喷砂组和喷砂+酸蚀组试件表面的粗糙度明显高于酸蚀处理组;喷砂和喷砂+酸蚀组的表面处理效果差异不大,喷砂组的4类试件表面粘结剂残留最少。结论:3种表面处理方法均能满足临床正畸的需求。喷砂组去除托槽后对试件表面的影响最小,喷砂联合酸蚀处理并不能显著增加剪切强度。 [关键词] 陶瓷托槽 剪切强度 瓷修复体 表面处理     

Luting glass ceramic restorations using a selfadhesive resin cement under different dentin conditions

Objectives

The aim of this study was to investigate the bond strength of ceramic restorations luted using a self-adhesive resin cement (RelyX Unicem, 3M ESPE) under different dentin conditions.

Material and Methods

In the experimental groups, ceramic restorations were luted to bovine incisors with RelyX Unicem under the following conditions: [Dry dentin]: surface was dried using air stream for 15 s; [Moist dentin]: excess dentin moisture was removed with absorbent paper; [Bonding agent]: Clearfil SE Bond (Kuraray) self-etching adhesive system was previously applied to dentin. In the Control group, cementation was done using an etch-and-rinse adhesive (Excite DSC) and Variolink II resin cement (Ivoclar Vivadent). Photoactivation of the resin cements was performed with UltraLume LED 5 unit (Ultradent). The restorations (n=5 per group) were sectioned into beams and microtensile testing was carried out. Data were subjected to ANOVA and Tukey''s test (p<0.05). Failure modes were classified under Scanning Electron Microscopic (SEM) (×120 magnification).

Results

The bond strength was dependent on the moisture status of the dentin. Bond strength in the "dry dentin group" was significantly lower than that of all other groups, which showed similar results. A predominance of mixed failures was detected for the control group, while a predominance of adhesive failures was observed for the "bonding agent" and "dry dentin" groups. The "moist dentin" group presented predominantly cohesive failures within the luting material. The previous application of a self-etching adhesive showed no significant effect.

Conclusions

Only excess dentin moisture should be removed for the cementation of ceramic restorations with self-adhesive resin cements.