不同粘固剂对 IPS-Empress 2后牙全瓷冠边缘适合性的影响

目的 :探讨不同粘固剂粘固的IPS Empress 2后牙全瓷冠的边缘适合性。方法 :采用印模复制和扫描电镜技术 ,测量磷酸锌粘固剂、PanaviaF树脂粘结系统和Dyracteompomer粘结剂粘固的IPS Empress 2后牙全瓷冠咀嚼模拟试验前后的边缘粘固剂厚度 ,并观察粘固剂表面状态。结果 :3种粘固剂粘固的全瓷冠边缘粘固剂厚度无显著性差异 (P >0 .0 5 ) ;磷酸锌粘固剂粘固的全瓷冠边缘粘固层有明显缺损 ,且咀嚼模拟试验后缺损增多 ,而另两种树脂类粘固剂未见明显缺损。结论 :PanaviaF树脂粘结系统和Dyractcompomer粘结剂粘固的IPS Empress 2后牙全瓷冠具有良好而稳定的边缘适合性     

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。     

不同粘接剂对二氧化锆桩固位力的影响

目的探讨不同粘接剂对二氧化锆桩与根管内牙本质粘接强度的影响。方法将60颗完整无龋坏的离体上颌中切牙自釉牙骨质界处截断牙冠,根管桩道预备,制作二氧化锆桩核。60颗牙随机分为6组,分别用磷酸锌水门汀、聚羧酸锌水门汀、玻璃离子水门汀i、Bond加LuxaCore双固化树脂、RelyX Unicem树脂、32%磷酸加ESPE RelyX Unicem树脂粘固二氧化锆桩核。万能力学试验机进行推出测试,记录粘接强度,并对数据行统计学分析。结果 32%磷酸加ESPE RelyX Unicem树脂组、ESPE RelyX Unicem树脂组i、Bond加Luxa Core树脂组、聚羧酸锌水门汀组、玻璃离子水门汀组、磷酸锌水门汀组的二氧化锆桩粘接强度分别为（15.06±1.80）MPa、（11.57±1.33）MPa（、10.42±1.24）MPa（、7.30±1.05）MPa（、6.99±0.87）MPa（、3.97±0.95）MPa,固位力依次降低。其中32%磷酸加ESPE RelyX Unicem树脂组的固位力显著高于其他组,两两比较差异均有统计学意义（P〈0.05）;ESPE RelyX Unicem树脂组与Luxa Core树脂组之间（P=0.590）,聚羧酸锌组和玻璃离子组之间（P=0.490）的差异均无统计学意义;磷酸锌水门汀的粘接强度最低,与其它组比较差异均有统计学意义（P〈0.05）。结论临床粘固二氧化锆桩,树脂类粘接剂固位力较强,自粘接系统加用酸蚀技术可以显著提高二氧化锆桩在根管内的粘接强度。     

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。     

2种纤维桩核修复方案的临床效果比较

目的比较在纤维桩修复中,自酸蚀粘接系统和自粘接桩核树脂水门汀临床修复效果。方法选取100例患者220颗需要桩核冠修复的前磨牙或前牙,随机分为2组,分别采用玻璃纤维桩+自粘接桩核树脂水门汀修复方案和玻璃纤维桩+自酸蚀粘接系统+桩核树脂修复方案,2组患牙均用烤瓷熔附金属全冠或全瓷冠修复牙体外形。36个月后复查,统计2组修复的成功率,并用χ2检验。结果自粘接组有103颗牙(46例)得到评价,无桩核脱落,无纤维桩折断、牙根折裂,桩核修复成功率100%;自酸蚀粘接组有98颗牙(48例)得到评价,桩核脱落1颗,未发生纤维桩折断、牙根折裂,桩核修复成功率98.99%,两者差别无统计学意义。结论在玻璃纤维桩桩核修复中,采用自粘接桩核树脂水门汀和自酸蚀粘接系统+桩核树脂均能取得良好的临床效果。     

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.     

不同树脂粘固剂对瓷与牙本质粘接强度的比较研究

目的 评价不同种类树脂粘固剂与瓷-牙本质粘接强度的差异,以期为临床提供参考.方法选取无龋坏青年人前磨牙制备牙本质粘接面,铸造直径为3 mm、高为3 mm的圆柱状瓷块(IPS e.max Press)80个,分为A、B、C、D、E 5组.分别选用树脂粘固剂A(Variolink Ⅱ)、B(MultilinkAutomix)、C(Multilink Sprint)、D(Rely X Unicem)和E(BisCem)将瓷块粘固于牙本质粘接面上,每组制成16个试样.37℃水储24 h后每组8个试样直接测试剪切粘接强度,另8个试样进行5000次冷热循环后测试粘接强度,扫描电镜观察粘接面形态.对同种粘固剂冷热循环前后的粘接强度进行双样本t检验.结果冷热循环前A组粘接强度[(22.3±3.9)MPa]最大,B组[(18.1±3.5)MPa]次之,再次为D组[(14.1±2.3)MPa]和E组[(11.7±4.2)MPa],C组[(11.3±3.6)MPa]最小.冷热循环后A组粘接强度[(17.8±2.3)MPa]仍最大,B组[(14.4±3.5)MPa]和D组[(13.2±2.5)MPa]次之,再次为E组[(8.9±3.2)MPa],C组[(7.0±2.4)MPa]最小.与冷热循环前相比,冷热循环后A、B、C 3组粘接强度均下降,差异有统计学意义(P<0.05);D组和E组粘接强度下降不明显(P>0.05).结论以全酸蚀粘接技术为基础的树脂粘固剂的粘接强度大于以自酸蚀粘接技术为基础的树脂粘固剂和自粘接型树脂粘固剂.     

两种粘接剂对氧化锆全瓷冠粘接效果的比较

目的 比较树脂加强型玻璃离子和自粘接树脂型水门汀粘接剂对氧化锆全瓷冠的临床粘接效果.方法 选取66例患者100颗需要进行氧化锆全瓷冠修复的患牙,随机分为两组(n=50),分别采用3M RelyXTMLuting树脂加强型玻璃离子粘固剂(RelyX L组)和3M RelyXTM U200通用自粘接树脂水门汀(RelyX U组)粘接.两年后复查,检查修复体的固位情况及边缘密合性,比较两组修复的成功率.结果 RelyX L组修复成功率98.0％;RelyX U组修复成功率100.0％,两组间差异无统计学意义.结论 在进行氧化锆全瓷冠修复时,采用树脂加强型玻璃离子和自粘接树脂型水门汀粘接剂均能取得良好的临床粘接效果.     

Er：YAG激光备洞与树脂充填微渗漏的实验研究

目的：评价Er：YAG激光备洞对树脂充填材料边缘微渗漏的影响。方法：选择48颗年轻前磨牙随机分成4组,每组12颗牙,用Er：YAG激光或高速牙钻制备ⅴ类洞。对照组：牙钻备洞＋35%磷酸酸蚀;实验1组：激光备洞＋35%磷酸酸蚀;实验2组：激光备洞＋自酸蚀粘接;实验3组：单纯激光备洞。树脂充填,经冷热循环试验后染色24h,体视显微镜下观察微渗漏,统计学处理数据。结果：龈壁的染料渗透,4组间无统计学差异;壁的染料渗透,以实验3组较明显,与对照组、实验1、2组有统计学差异（P〈0.05）;各组内壁的染料渗透均比龈壁轻,但没有统计学差异。结论：Er：YAG激光备洞,35%磷酸酸蚀或自酸蚀粘接处理可减少洞壁与树脂充填边缘的微渗漏。     

4种粘接系统对龋损影响牙本质的粘接效果的比较

目的：比较4种不同的粘接系统对正常牙本质和龋损影响牙本质的粘接强度。方法：24颗近中袷面中龋的人离体磨牙，在龋损检知液监控下用慢速球钻去龋，在远中袷面健康牙本质上制备相同深度的窝洞。随机分为4组，分别用4种粘接系统（Prime＆Bond NT，Adper Single Bond2，Adper Prompt和XenoⅢ）按照使用说明进行粘接，用树脂（FiltekP60）修复后保存于37℃的水中。沿牙长轴方向将树脂和牙齿从颊舌方向片切，厚度约为1．0mm，并修整成粘接面（正常牙本质或龋损影响牙本质）面积约1mm。的试件，进行微拉伸实验，并用扫描电镜观察粘接面形态。结果：4种粘接系统在正常牙本质上获得的粘接强度均强于在龋损影响牙本质上获得的强度（P〈0．05）；2种全酸蚀粘接系统在2种牙本质上获得的粘接强度均强于2种自酸蚀粘接系统获得的强度（P〈0．05）。扫描电镜观察，混合层在龋损影响牙本质上表现得厚但更疏松；与正常牙本质相比，龋损影响牙本质上形成的树脂突少。结论：2种全酸蚀粘接系统无论在正常牙本质还是龋损影响牙本质上均能获得比2种自酸蚀粘接系统更强的粘接力。     

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.     

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.     

Retentive strength, disintegration, and marginal quality of luting cements.

This study evaluated the retention of complete crowns by using five different methods of cementation. Complete crowns were prepared with standardized dimensions on extracted human molars. Metal crowns were cast with a high noble gold ceramic alloy and were cemented with zinc phosphate cement, glass ionomer cement, composite resin cement, composite resin cement with a dentinal bonding agent, and adhesive resin cement. The retention was measured by subjecting the specimens to tensile load until fracture occurred. The disintegration was measured according to American Dental Association Specification No. 8, and the condition of the cements at the margins of crowns was analyzed by use of a scanning electron microscope. Kruskal-Wallis one-way analysis of variance revealed statistically significant differences between the mean retentive strengths. The retention of the zinc phosphate and the glass ionomer groups was significantly different from that of the adhesive resin group. The retention of the adhesive resin cement was 65% greater than the retention of the composite resin and the composite resin/dentinal bonding agent group, but the Mann-Whitney Wilcoxon rank sum test did not depict this difference as significant. The mean +/- SD of the disintegration for the zinc phosphate, the glass ionomer cement, and the composite resin cement was 0.025 +/- 0.013, 0.023 +/- 0.011, and 0.017 +/- 0.001, respectively. The scanning electron microscope analysis of the margins revealed that the composite resin cement was almost intact, the zinc phosphate was subjected to limited disintegration, and the glass ionomer displayed the worst marginal integrity.     

Fracture load of composite resin and feldspathic all-ceramic CAD/CAM crowns

STATEMENT OF PROBLEM: Various machinable materials are currently used with computer-aided design/computer-assisted manufacturing (CAD/CAM) technologies for the chairside fabrication of restorations. However, properties of these new machinable materials, such as fracture load, wear, marginal deterioration, and color stability, should be investigated in vitro under replicated clinical conditions prior to time-consuming clinical studies. PURPOSE: This study investigated the effect of cyclic loading fatigue and different luting agents under wet conditions on the fracture load of CAD/CAM machined composite resin and all-ceramic crowns. MATERIALS AND METHODS: Ninety-six intact human maxillary premolars were prepared for composite resin and all-ceramic crowns with the following preparation criteria: 6-degree axial taper, 1.5-mm shoulder finish line placed 0.5 mm occlusal to the cemento-enamel junction, 1.5-mm axial reduction, 2-mm occlusal reduction, and 5-mm occluso-gingival height. Sixteen unprepared premolars served as controls. Forty-eight all-ceramic crowns (Vita Mark II) and 48 millable composite resin crowns (MZ100 Block) were fabricated using a CAD/CAM system (Cerec 3). Three luting agents-RelyX ARC (RX), GC Fuji CEM (FC), and zinc phosphate cement (ZP)-were used for cementation (n = 16). After 1-week storage in water, half of the specimens (n=8) in each subgroup were cyclically loaded and thermal cycled under wet conditions for 600,000 masticatory cycles and 3500 thermal cycles (58 degrees C/4 degrees C; dwell time, 60 seconds) in a masticatory simulator; the other half (n = 8) were fractured without cyclic loading. All specimens were loaded in a universal testing machine with a compressive load (N) applied along the long axis of the specimen at a crosshead speed of 1 mm/min until fracture. Fracture loads (N) were recorded for each specimen. Three-way analysis of variance was used to detect the effects of the experimental factors (crown material, luting agent, and loading conditions) on the fracture load. The comparison with the unprepared natural teeth as controls was done by means of t tests (alpha=.05). RESULTS: Analysis of variance revealed a statistically significant influence of the luting agent and the cyclic loading (P < .001), whereas the crown material had no significant influence. Cyclic loading fatigue significantly decreased the mean fracture load of test groups independent of the 3 luting agents used: MZ100/ZP, 827.1 to 552.5 N; MZ100/FC, 914.7 to 706.2 N; MZ100/RX, 955.9 to 724.4 N; Vita/ZP, 772.3 to 571.5 N; Vita/FC, 923.6 to 721.1 N; and Vita/RX, 929.1 to 752.7 N. However, there was no significant difference in the mean fracture load of control specimens before and after cyclic loading (1140.1 N and 1066.2 N, respectively). Adhesive luting agents RelyX ARC and GC Fuji CEM increased fracture load significantly compared to zinc phosphate cement. CONCLUSIONS: Cyclic loading fatigue significantly reduced the fracture loads of composite resin and all-ceramic crowns, whereas adhesive cementation significantly increased the fracture loads.     

Leakage of various types of luting agents

Freshly extracted molar teeth were prepared for complete cast gold crowns cemented with either zinc phosphate cement, polycarboxylate cement, glass ionomer cement, a resin luting agent, or a zinc oxide-eugenol temporary cement. The specimens were tested at 1-, 6-, and 12-month intervals with radioactive 45Ca. The specimens were sectioned, autoradiographs were made, and the marginal leakage was evaluated on a scale of 0 to 3. The results showed that zinc phosphate, polycarboxylate, and glass ionomer cements are equally suited for permanent cementation of restorations. The resin luting agent showed high initial leakage, indicating that it is not as desirable for permanent cementation purposes. The zinc oxide-eugenol cement showed increased leakage with time but is well suited for its indicated purpose, temporary cementation.     

The influence of different cements on the fracture resistance and marginal adaptation of all-ceramic and fiber-reinforced crowns

PURPOSE: This in vitro study investigated the marginal adaptation and fracture resistance of heat-pressed glass-ceramic and fiber-reinforced composite molar crowns luted with resin, resin-modified glass-ionomer, or zinc-oxide-eugenol-free cements. MATERIALS AND METHODS: A total of 24 heat-pressed all-ceramic and 24 glass fiber-reinforced composite crowns were constructed and cemented using the above-mentioned luting agents (eight crowns per cement). The restorations were thermocycled and mechanically stressed, and fracture resistance was determined. Marginal adaptation was evaluated before and after stress application using semiquantitative analysis in a scanning electron microscope. RESULTS: All-ceramic and fiber-reinforced composite crowns reached the highest fracture resistance after stress application in combination with the resin cement. When luted with resin-modified glass-ionomer or zinc-oxide-eugenol-free cements, the fracture resistance of all-ceramics decreased significantly, while the fiber-reinforced composite crowns maintained their fracture resistance level; the lowest values were found for zinc-oxide-eugenol-free cements. The marginal adaptation remained unchanged after stress for all-ceramics and fiber-reinforced composite restorations if they were luted with resin cements. Luting with resin-modified glass-ionomers significantly deteriorated the marginal adaptation after stress application, with the exception of the crown-cement interface of all-ceramics. CONCLUSION: The highest fracture resistance and marginal adaptation were found for all-ceramic and glass fiber-reinforced composite molar crowns if they were luted with resin cement.     

Effects of intra-core mechanical interlocks and cement type on full crown retention.

This study compared the retention of full cast crowns over cores of amalgam or a Bis-GMA composite resin when cemented with a Bis-GMA composite resin cement or a zinc phosphate cement. The surfaces of two groups of Bis-GMA composite cores were mechanically altered with a groove or dimples to provide physical retention; two other groups were either etched with 1.23% acidulated phosphate fluoride (APF) or exposed to a zinc oxide-eugenol interim luting agent before crown cementation. Control groups of unaltered composite or amalgam core served as comparison standards. The zinc phosphate cement provided significantly greater retention with the amalgam core than with any of the composite cores. The APF-treated composite cores had the least retention of any of the zinc phosphate cementations. Cementation failure over the composite cores was at the core surface. Crown retention over the control and dimpled-surface composite core with the resin cement was twice that with zinc phosphate, and significantly greater than retention of castings cemented with the resin cement over amalgam cores. Retention over amalgam cores was significantly greater with zinc phosphate cement than with the composite resin cement.     

Marginal Discrepancy of All-Ceramic Crowns Cemented on Implant Abutments

Purpose The purpose of this investigation was to determine the mean marginal discrepancy of all-ceramic crowns cemented on implant abutments. Materials and Methods Five Brånemark CeraOne abutments were connected to implant fixtures embedded in acrylic resin blocks. The marginal discrepancy was measured using a video camera connected to a digitizing board at four locations on each abutment for five samples in each of the following groups: all-ceramic caps (caps), all-ceramic crowns (crowns), and all-ceramic crowns cemented with zinc phosphate cement (cemented crowns). Results The mean marginal discrepancies were as follows: caps, 99.0 μm (SD, 16); crowns, 117.8 μm (SD, 20); and cemented crowns, 168.8 μm (SD, 23). Statistically significant differences were found between all three groups at the 99% level of confidence. In addition there were two significant differences between abutments. Conclusions Subgingival marginal discrepancies of the magnitude measured in this study have been shown to cause periodontal problems. It is probable that the marginal discrepancy of CeraOne restorations, as tested, can be improved. Efforts should be made to enhance the marginal accuracy of these restorations.     

Interim luting agents, composite core surface hardness and retention of interim and final restorations

This study compared the effects of ZOE interim cement on the retention of interim acrylic and final cast crowns (cemented with zinc phosphate) over cores of current conventional and hybrid composite resin formulae, and a non-eugenol interim cement (NOG) and a calcium hydroxide liner (CaOH2) on interim and final retention values over hybrid cores. Results were compared to retention of cast crowns over amalgam cores. Retention was measured with an Instron Testing Machine. Location of cement failure during separation was recorded. Surface hardness of each group was compared. Retention of cast crowns cemented with zinc phosphate over amalgam cores was significantly higher than that of any of the resin core groups (ANOVA, P less than 0.05, Sheffe Contrast). There was no significant difference in final casting retention cemented over hybrid or conventional resin cores exposed to ZOE (13.625 vs 14.125 Kg). Final casting retention differences were not significant between the three interim cement groups. Final retention of all groups exposed to an interim luting agent were significantly less than the composite control groups. The use of CaOH, as an interim luting agent for acrylic crowns over hybrid cores compared to ZOE or NOG, should afford significantly greater retention with no adverse effect on the retention of the final casting. While the surface hardness of both types of composite resin was adversely affected by exposure to interim luting agents as compared to controls, there was no correlation between final casting retention values and surface hardness of polished composite. The interim cements invariably failed at the interim acrylic crown interface while the zinc phosphate cement failed at the core interface.