树脂类粘结剂边缘厚度对全瓷冠边缘微渗漏的影响

目的：研究树脂类粘结剂边缘厚度与全瓷冠边缘微渗漏的相关关系。方法：16颗上颌第三磨牙经标准牙体制备，制作IPS－Empress 2全瓷冠，分两组用多组份树脂粘结剂和自炽结多聚酸改性树脂炽结剂粘固，经温度循环试验后，用扫描电镜测量边缘粘固剂厚度，再将样本浸入2％品红溶液24小时，系列切片，用体视显微镜观测边缘微渗漏程度。结果；两种树脂粘结剂边缘粘固剂厚度与牙－粘固剂界面和全瓷冠－粘固剂界面边缘微渗漏程度均无相关关系（P＞0．05）。结论：树脂类粘结剂边缘粘固剂厚度若在理想的临床要求范围内，不足以影响全瓷冠边缘微渗漏程度。     

不同粘固剂对全瓷冠边缘完整性影响的研究

目的研究不同粘固剂粘固的全瓷冠边缘完整性。方法全瓷冠修复24颗离体上颌第三磨牙,随机分成3组,每组8个,分别用自酸蚀树脂粘接系统、Compomer粘固剂和磷酸锌粘固剂粘固,用扫描电镜观测标本牙疲劳试验前后边缘完整性及粘固剂表面质量。结果自酸蚀树脂粘接组试验前后完整边缘率均高于95%,Compomer组和磷酸锌粘固剂粘固组完整边缘率分别为16%~19%和5%,组间均有显著性差异（P〈0.001）;自酸蚀树脂粘接组边缘区粘固剂缺损显著小于其它两组（P〈0.05）。结论用自酸蚀树脂粘接系统粘固全瓷冠有优良的边缘完整性和边缘区表面质量。     

两种粘结剂粘结CAD/CAM氧化锆全瓷冠边缘微渗漏的研究

目的评价两种不同粘结剂在CAD/CAM氧化锆全瓷冠修复中的边缘微渗漏情况。方法制作10个CAD/CAM氧化锆全瓷冠,随机分成2组,分别采用磷酸锌水门汀粘结剂和Panavia F树脂粘结剂粘固于前磨牙,经温度循环试验后,将样本浸入2%品红溶液中24h,用体视显微镜观察牙-粘结剂界面边缘微渗漏状况,并进行分级评估。结果采用SPSS 17.0软件对2组的微渗漏程度进行统计分析,得出Panavia F树脂粘结剂微渗漏小于磷酸锌水门汀粘结剂(χ2=81.142,P<0.05)。结论 Panavia F树脂粘结剂具有较优越的抗边缘微渗漏性能。     

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目的探讨IPS Empress 2可铸玻璃陶瓷嵌体修复后牙牙体缺损的临床疗效。方法对沈阳市和平区牙病防治所2010年6月至2012年6月接受治疗的后牙牙体缺损患者30例（48颗患牙）,采用IPS Empress 2可铸玻璃陶瓷嵌体修复,随访观察6个月至2年,参照改良的美国公共卫生服务（USPHS）评价标准对修复体的边缘适合性、外形、颜色匹配、继发龋发生以及磨损与折裂情况进行评价。结果 IPS Empress可铸玻璃陶瓷嵌体具有良好的边缘适应性及外形,色泽稳定,强度较高,未发现继发龋。结论 IPS Empress 2可铸玻璃陶瓷嵌体是一种修复后牙牙体缺损效果较好的修复体。     

非贵金属烤瓷冠边缘适合性的体外实验研究

目的研究应用非贵金属合金制作烤瓷基底冠的边缘适合性。方法制作20颗金属烤瓷全冠,用立体显微镜分别测量其粘固前、后边缘浮出量及粘固剂的厚度,研究烤瓷冠的边缘适合性及其与粘固剂厚度的关系。结果金属烤瓷冠粘固前后的边缘浮出量因粘固而明显增加。结论粘固后冠边缘间隙的大小与粘固前冠边缘间隙的大小之间的关系呈线性相关,粘固后冠边缘间隙的增加量与粘固前冠边缘间隙大小的关系没有线性相关的关系;粘结对全冠修复体的边缘浮出量有影响。     

后牙瓷嵌体修复的临床应用

目的 研究IPS Empress可铸玻璃陶瓷系统用于后牙嵌体修复的临床疗效。方法 制作IPS Empress瓷嵌体51件，戴用0．5～2．0年后评价其颜色、形态、修复体周围龋、修复体边缘密合度、修复体磨耗及折断情况。结果 IPS Empress瓷嵌体修复体边缘适合性的合格率为96．1％，修复体形态的合格率是98．1％，修复体颜色的合格率为100％，磨损和折裂的合格率是94．1％，无修复体周围龋。结论 IPS Empress瓷嵌体是一种效果好的全瓷修复体。     

两种粘结剂对纤维根管桩粘固力的实验研究

目的比较磷酸锌水门汀和双固化树脂粘结剂粘结纤维树脂根管桩的粘固力差异,为临床合理选择粘结剂提供实验依据。方法选用经体外根管治疗的新鲜拔除人上颌中切牙60颗,随机分成2组,每组30颗,分别用磷酸锌水门汀和双固化树脂粘结剂粘结纤维树脂桩,用万能力学测试机测试纤维桩脱落个数并进行χ2检验。结果 2组脱落个数无显著性差异(P>0.05)。结论磷酸锌水门汀和双固化树脂水门汀都可以用于粘固纤维树脂根管桩,用磷酸锌水门汀可以降低医疗成本。     

三种全瓷冠的临床效果观察

目的总结应用3种陶瓷全瓷冠的临床效果,为全瓷冠的材料选择应用提供参考。方法选择门诊患者90例,采用IPS Empress热压铸造陶瓷、In-ceram渗透陶瓷以及Cerec2 CAD/CAM技术制作前牙全瓷冠各30件,临床定期观察。结果修复体咀嚼功能好,美观,适合性好,无食物嵌塞,无继发龋及龈炎。Cerec Vita MarkⅡ全瓷冠有1件冠折裂,2件出现裂纹;IPS EmpressⅡ全瓷冠有2件出现裂纹,未折裂;In-Ceram全瓷冠未出现裂纹、折裂现象。结论In-Ceram全瓷冠临床应用效果好。     

不同粘结材料对玻璃瓷冠修复体抗碎裂载荷影响的研究

目的 :研究不同粘结材料对前磨牙玻璃瓷冠抗碎裂载荷的影响 ,寻求理想的临床粘结方法。方法 :3 0颗拔除的正畸前磨牙随机分为 3组 ,进行标准基牙预备。轴面聚合角为 5° ,牙合面交角 13 5° ,肩台宽 1mm。制成均匀厚度为 1mm的玻璃瓷冠 ,分别由磷酸锌水门汀、玻璃离子水门汀、光固化树脂粘结于牙体上。垂直加压于人造冠直至碎裂 ,各实验组间抗碎裂载荷差异用t检验分析。结果 :光固化树脂粘结的抗碎裂载荷明显高于磷酸锌水门汀和玻璃离子水门汀粘固的抗碎裂载荷 (P <0 .0 5 )。结论 :光固化树脂粘结剂为理想的粘结材料 ,有利于提高玻璃瓷冠修复体的整体强度。     

三种粘接剂对IPS e.max CAD全瓷冠微 渗漏和适合性的影响

目的 比较Duo-Link、Variolink N和Kerr NX3三种树脂粘接剂粘接对离体牙IPS e.max CAD全瓷冠微渗漏和适合性的影响.方法 收集40个离体上前磨牙,随机分为4组,常规制作IPS e.max CAD全瓷冠,分别用Duo-Link、Duo-Link+酸蚀、Variolink N以及Kerr NX3进行粘接.经冷热循环后,应用扫描电镜观察微渗漏和适合性情况,并进行统计学分析.结果 4组IPS e.max CAD全瓷冠的边缘微渗漏不同,Duo-Link组值最大,Kerr NX3值最小,Duo-Link组的边缘适合性差于其他3组,Kerr NX3的牙合面适合性优于其他3组.以上差异均有统计学意义(P<0.05).结论 三种树脂粘接剂粘接CEREC AC系统的IPS e.max CAD全瓷冠,对其边缘微渗漏和内部适合性均有影响.全酸蚀、湿粘接树脂粘接剂能有效减少边缘微渗漏,获得良好的边缘和内部适合性.IPS e.max CAD全瓷冠加工精准度高,可以获得良好的边缘和内部适合性.     

Effect of different luting materials on the marginal adaptation of Class I ceramic inlay restorations in vitro.

OBJECTIVES: The aim of this in vitro study was to assess the marginal adaptation of prefabricated Class I ceramic inlay restorations placed with various luting materials. METHODS: Forty-two standardized occlusal cavities were prepared in extracted human molars with diamond burs exactly corresponding to the dimensions of prefabricated glass ceramic inlays. The prepared teeth were randomly assigned to seven groups of six teeth each and restored using (1). the composite resin Tetric Ceram in increment technique [Group I] or (2). ceramic inlays (Cerana) luted with: the composite based materials Dual Cement [Gr. II] and Panavia 21 [Gr. III], the compomer material Dyract Cem [Gr. IV], Dyract Cem with additional use of Prime & Bond 2.1 [Gr. V], the silicophosphate cement Trans-Lit [Gr. VI], or the ethylcyanoacrylate Cyano-Veneer [Gr. VII]. Marginal adaptation was evaluated by SEM-analyses before and after thermal cycling (2500 cycles; 5-55 degrees C) and mechanical loading (100N; 500000 cycles) using replica models. Kruskal-Wallis H-test and Mann-Whitney U-test were used for statistical analyses. RESULTS: Group I (increment technique) as well as Groups II-V (inlay technique) revealed high percentages of perfect marginal adaptation in over 95% of the analyzed margins, both before and after thermo-mechanical loading. Statistical significant differences could not be detected within these groups. All inlays luted with silicophosphate cement (Group VI) and four of six inlays applied with Cyano-Veneer (Group VII) fractured under occlusal load. SIGNIFICANCE: A stable bonding to the enamel and to the ceramic inlay was achievable with the composite luting resins Dual Cement and Panavia 21 as well as with the compomer based luting material Dyract Cem but not with the use of the silicophosphate cement Trans-Lit or the ethylcyanoacrylate Cyano-Veneer.     

In vitro evaluation of fit of adhesively luted ceramic inlays

PURPOSE: The purpose of this study was to evaluate both marginal and overall adaptation of 4 adhesively luted ceramic inlay systems. MATERIALS AND METHODS: A total of 40 extracted teeth were restored with mesio-occlusodistal ceramic inlays using 4 different techniques: Colorlogic, IPS Empress, Celay direct, and Celay indirect. After cementation with a resin luting agent, the samples were sectioned along a mesiodistal line passing through the center of the restoration. The thickness of the cement was measured at the margins and at several points along the inside of the restorations by means of a stereomicroscope fitted with a measuring grid. RESULTS: The results were analyzed by one-way analysis of variance. The marginal precision of IPS Empress and Colorlogic inlays averaged below 50 microns. Marginal precision of Celay inlays averaged between 110 and 130 microns. IPS Empress and Celay inlays showed a uniform distribution of the cement along the entire prepared surface. Colorlogic inlays showed an uneven distribution of the cement film. CONCLUSION: IPS Empress inlays showed the best clinical features compared to Colorlogic and Celay inlays.     

Marginal discrepancies and leakage of all-ceramic crowns: influence of luting agents and aging conditions

PURPOSE: This study evaluated the marginal discrepancies and leakage of all-ceramic crowns cemented with different luting agents after fatigue tests. MATERIALS AND METHODS: Forty-eight all-ceramic crowns were cemented onto natural molars. Zinc-phosphate cement, compomer cement, and an adhesive composite resin luting system were used in 16 specimens each. Sixteen metal-ceramic crowns were cemented with zinc-phosphate cement as a control. Half of the specimens in each group were fatigued in a chewing simulator for 600,000 loading cycles with 3,500 thermocycles. The others received the 3,500 thermocycles only. An impression-replica technique and SEM were used for evaluation of the marginal discrepancies. Leakage of the specimens was microscopically assessed. RESULTS: There were no significant differences between marginal discrepancies of the groups, with the exception of porcelain shoulder margins in the metal-ceramic group, which had significantly larger discrepancies (P < .01). There was no significant effect of the fatigue tests on marginal discrepancies. However, significant differences of leakage were found between the groups cemented with the different luting agents after both fatigue tests. The adhesive composite resin luting system demonstrated the least leakage. The compomer cement showed an intermediate level of leakage, and the zinc-phosphate cement showed severe leakage that extended through the dentinal tubules to the pulp chambers. No significantly different effect of the two fatigue tests on the leakage was found. CONCLUSION: The adhesive composite resin luting system showed clinically acceptable marginal discrepancies and an excellent ability to minimize leakage of all-ceramic crowns.     

Marginal adaptation of three-unit fixed partial dentures constructed from pressed ceramic systems

PURPOSE: This study compares the marginal accuracy of posterior metal ceramic (MC), all-ceramic IPS Empress 2 and experimental pressed ceramic (EPC-VP 1989/4) three-unit fixed partial dentures (FPD), before and after luting and after thermo-mechanical fatigue in a dual-axis chewing simulator. MATERIALS AND METHODS: Caries-free human teeth (n=160) were used as abutments for the fabrication of eighty posterior three-unit FPD, divided into two test-groups, IPS Empress 2 and EPC, of 32 samples each and one control group of 16 samples metal ceramic FPD. All FPD were cemented with Variolink II dual-curing resin cement. Half of the samples in each group were exposed to a dual-axis chewing simulator. RESULTS: The geometric mean marginal gap values (microm, before cementation, after cementation and after thermo-mechanical fatigue) amounted to 53, 63 and 62 for the ceramic metal FPD, 57, 71 and 68 for the Empress 2 FPD and 55, 67 and 68 for the EPC FPD. In all groups a statistically significant increase in marginal gap width was observed after cementation. The effect of functional loading in the chewing simulator on marginal gap was not significant. Marginal gap was lowest in the control group but differences with all-ceramic materials were small in all evaluation stages. CONCLUSION: Within the limits of this investigation, it can be concluded that marginal gap values of these all-ceramic materials and conventional MC techniques are on a similar level. In particular, almost all marginal gap values observed in this study were within the limits of clinical acceptance.     

An in-vitro investigation of the accuracy of fit of Procera and Empress crowns

The current study aimed to investigate the accuracy of fit and the reproducibility of inner crown profile for two types of high strength ceramics, IPS Empress and Procera. Procera and Empress crowns with four different morphologies were cemented to dies using zinc phosphate dental cement. Vertical and horizontal sections were made through each of the crown/die preparations and images of the vertical sections were compared for curvature reproduction by alignment using image processing. Measurements were made on horizontal sections to determine cement layer thickness. Alignment of the crowns using image analysis identified quantifiable variations in the inner surface profile compared with the outer surface of the die. The largest differences occurred from the cusp tips to the occlusal adaptation area and differences in surface profile were less pronounced for Procera than Empress crowns. Marginal gap varied independently of ceramic or internal crown shape from 7-529 microm for Procera and 26-548 microm for Empress. IPS Empress has a superior ability to reproduce the inner surface profile of the crown morphologies investigated compared with Procera. The reduced reproduction of surface profile was associated with an increased cement thickness at the occlusal contact area that may inadvertently lead to failure of the crowns functional characteristics.     

Seating and retention of complete crowns with a new adhesive resin cement.

The retentive property of cast gold complete crowns cemented with an adhesive resin cement (Panavia Ex) was compared with retention of crowns cemented with zinc phosphate cement (Flecks) and the conventional resin cement (Comspan). The effect of these agents on seating of crowns also was evaluated. Panavia cement exhibited the highest retentive strength, with values almost twice those obtained with zinc phosphate cement. However, the difference in mean retention values of crowns cemented with Comspan cement or with zinc phosphate cement was not statistically significant. Both resin cements used in this study provided better seating of crowns than did zinc phosphate cement.     

Microleakage of core materials for complete cast gold crowns

This study evaluated the microleakage patterns of complete cast-gold crowns cemented onto teeth rebuilt with pin-retained cores made from cast gold, amalgam, composite resin, and silver-reinforced glass ionomer by using three different cements (zinc phosphate, glass ionomer, and resin cement). Crowns cemented onto unrebuilt tooth preparations with zinc phosphate cement served as controls. The cemented specimens were thermocycled between 4 degrees and 50 degrees C in waterbaths. They were then embedded in epoxy resin and sectioned. The extent of marginal microleakage was evaluated with a stereomicroscope and scored. The findings indicated that the type of luting agent used appeared to affect microleakage more than the core material. No significant differences in the degree of microleakage were found under crowns cemented onto teeth rebuilt with the four core materials when cemented with the same luting cement.     

Comparison of the tensile bond strengths of cast metal crowns luted with resin cements

The limitation of photoactivation of dual-polymerized resin cements along the margins of metal restorations may adversely affect the mechanical properties of these cements, thus impairing the retention of restorations. The aim of this study was to assess the bond strength of cast metal crowns cemented with three dual-polymerized resin cements, using a chemically-activated resin cement and zinc phosphate as controls. Fifty nickel-chromium alloy crowns were cast and randomly assigned to five groups of equal size. Castings were cemented on their corresponding metal dies with one of the tested luting agents: Scotchbond Resin Cement, Enforce and Panavia F (dual-polymerized resin cements), Cement-It (chemically-activated resin cement) and Zinc Phosphate Cement (zinc phosphate cement). Specimens were stored in distilled water at 37 degrees C for 24 h and then loaded in tension until failure. Panavia F and Zinc Phosphate Cement provided the highest and lowest bond strength means, respectively. Scotchbond Resin Cement, Enforce and Cement-It cements exhibited similar intermediate values, but with statistically significant difference compared to the other materials (P < 0.05). Even with the restriction or absence of light activation, all tested dual-polymerized resin cements produced significantly higher bond strength than did the zinc phosphate cement and yielded similar or better results than the chemically activated cement. It should be pointed out that the findings of this study relate to a test scenario which does not mimic clinical circumstances and that further work is required to identify the clinical significance of the reported tensile bond strength differences between the different luting materials.