Effect of water aging on microtensile bond strength of dual-cured resin cements to pre-treated sintered zirconium-oxide ceramics

ObjectivesTo evaluate the hydrolytic stability of different dual-cure resin cements when luted to zirconia ceramic.MethodsEighteen cylinder-shaped zirconia blocks (Cercon Zirconia, Dentsply) were conditioned with: Group 1, no treatment; Group 2, sandblasting (125 μm alumina–Al₂O₃-particles); Group 3, tribochemical silica coating (50 μm silica-modified Al₂O₃ particles). Ceramic blocks were duplicated in composite resin (Tetric Evo Ceram, Ivoclar-Vivadent). Composite disks were luted to pre-treated ceramic surfaces using: (1) Clearfil Esthetic Cement (CEC; Kuraray); (2) Rely X Unicem (RXU; 3M ESPE); (3) Calibra (CAL; Dentsply Caulk). After 24 h, bonded samples were cut into microtensile sticks (1 mm²). Half of the sticks were loaded in tension until failure (cross-head speed of 0.5 mm/min). The remaining half was tested after 6 months of water storage at 37 °C. Data was analyzed with three-way ANOVA and Tukey’s test (P <0.05). Fractographic analysis was performed by SEM.ResultsAfter 24 h, bond strength of CEC to zirconia was significantly higher than that of RXU and CAL, independently from the ceramic pre-treatment (P <0.001). Using CAL, all samples failed prematurely except when luting to sandblasted surfaces. After 6 months of water aging, bond strength of CEC significantly decreased. RXU did not significantly alter bond strengths. Adhesion of sandblasted specimens luted with CAL fell over time. Micromorphological alterations were evident after water storage.SignificanceResin–ceramic interfacial longevity depended on cement selection rather than on surface pre-treatments. CEC and RXU were both suitable for luting zirconia. Water aging played an important role in the durability of zirconia-to-composite chemical bonds.     

Bonding quality of contemporary dental cements to sandblasted esthetic crown copings*

Aim: To evaluate the shear bond strength of current luting cements to sandblasted crown‐coping substrates. Methods: Specimens of nickel‐chromium, pressable glass ceramic, and zirconia crown‐coping substrates were sandblasted in three groups (n = 30 each) with 50 (group 1), 110 (group 2), and 250 μm (group 3) alumina particles at a pressure of 250 kPa. Cylinders of glass ionomer, universal resin, and self‐adhesive resin cements were then built up on the sandblasted substrate surfaces of each group (n = 10). All bonded specimens were stressed to evaluate the cement–substrate shear bond strength. Both the mode and incidence of bond failure were also considered. Results: No difference was noticed between all test groups in terms of cement–substrate bond strength. In comparison to self‐adhesive type, the universal resin cement provided lower bond strengths to both metal and glass–ceramic substrates in group 1. The self‐adhesive resin cement provided the highest bond strengths to the zirconia substrates in groups 2 and 3. The adhesive type of bond failure was common in the metal and zirconia substrates in all groups. Conclusions: Cement–substrate bonding quality is not affected by the size of sandblasting particles. Resin cements bond better to different coping substrates. Self‐adhesive resin cement is the best choice to bond zirconia‐based substrates.     

喷砂处理对二氧化锆陶瓷表面性状及树脂粘接的影响

目的 探讨Al2O3喷砂处理对二氧化锆陶瓷表面粗糙度、元素构成及树脂粘接耐久能力的影响.方法 可切削二氧化锆陶瓷片试件60个经烧结、研磨、清洗后,30个试件表面在0.3 MPa压力下接受50 μm Al2O3颗粒喷砂处理20 s,形成喷砂后试件(另30个不喷砂试件为喷砂前试件).使用激光共聚焦显微镜对喷砂前、后的陶瓷表面粗糙度进行测量.使用X射线能谱仪对喷砂前、后的陶瓷表面元素成分进行定性定量分析.试件分为6组,每组10个:1、2组分别由喷砂前、后试件与常规树脂粘接剂(Duolink)粘接;3、4组分别由喷砂前、后试件分别与含磷酸酯类功能性单体的树脂粘接剂(Panavia F)粘接;5和6组分别由喷砂前、后试件经含磷酸酯类功能性单体的硅烷偶联剂(Clearfil Ceramic Primer)处理后与Panavia F粘接.各组试件分为两个亚组,分别经0、10 000次冷热循环后测量剪切粘接强度.使用单因素方差分析和独立样本t检验进行统计.结果 喷砂后陶瓷表面氧元素原子百分比[(65.03±1.48)%]显著低于喷砂前 [(75.85±1.61)%],锆元素原子百分比[(17.30±1.43)%]显著高于喷砂前[(9.62±0.29)%](P<0.001),同时表面粗糙度高于喷砂前(P<0.001).冷热循环降低了所有组粘接强度(P<0.001),其中1、2组试件在循环过程中全部脱落,3、5组粘接强度[(0.59±0.17)、(0.89±0.84)MPa]显著低于4、6组粘接强度[(14.63±3.03)、(16.64±1.90) MPa],6组粘接强度显著高于4组(P<0.001).所有试件粘接断裂模式均为陶瓷-粘接剂界面断裂.结论 Al2O3喷砂处理在增加二氧化锆陶瓷表面粗糙度和表面积的同时,也增加了表面锆元素的质量和原子百分比,从而提高了二氧化锆陶瓷与含磷酸酯类功能性单体的树脂粘接剂间的化学粘接耐久能力.

Abstract：

Objective To evaluate the effect of Al2O3 particles sandblasting on the surface roughness, element composition and resin bond durability of zirconia ceramic. Methods Sixty 2.5 mm thick computer aided design and computer aided manufacture(CAD/CAM) zirconia ceramic (Vita Inceram YZ) plates were fired, polished and cleaned. Half of polished ceramic plates was sandblasted with 50 μm alumina particles at 0.3 MPa for 20 s. The surface roughness of polished and sandblasted ceramic surface were measured by 3D-laser scanning microscope, and the surface element weight and atom ratio of the ceramic surface were measured by energy disperse spectroscopy(EDS). Then polished and sandblasted ceramic plates were randomized into six groups. In Group 1 and 2 the polished and sandblasted ceramic plates were bonded irrespectively with conventional resin cement(DUOLINK) . In Group 3 and 4 the ceramic plates were bonded with resin cement containing MDP(Panavia F), In Group 5 and 6 the specimens were pretreated with silane coupler acitivated by MDP(Clearfil Ceramic Primer), then bond with Panavia F. The specimens of each test group were then divided into two subgroups, and to received shear test after 0 and 10 000 time thermal cycle. The data was analyzed by one-way ANOVA and independent t test. ResultsComparing with polishing, sandblasting reduced the oxygen atom and weight ratio of zirconia ceramic surface (P<0.001), and increased the zirconium atom and weight ratio (P<0.001), meanwhile increased the surface roughness (P<0.001). The bond strength between ceramic plates and resin cement in all test groups decreased after thermocycling (P<0.001). All specimen in test group 1 and 2 lost bond, and the bond strength of test group 3 and 5[(0.59±0.17), (0.89±0.84) MPa] were significantly lower than that of test group 4 and 6[(14.63±3.03), (16.64±1.90) MPa], and the bond strength of test group 6 were significanlty higher than that of test group 4. Conclusions Sandblasting improves durability of bond between zirconia ceramic and resin cement containing MDP, not only by increasing the roughness and area of ceramic surface, but also by changing its surface element composition to obtain more chemical bond.     

Influence of sandblasting granulometry and resin cement composition on microtensile bond strength to zirconia ceramic for dental prosthetic frameworks

ObjectivesTo evaluate the effect of the particle size of sandblasting and the composition of the resin cement on the microtensile bond strength (MTBS) to zirconia.MethodsForty zirconia blocks (Cercon, Dentsply) were polished and randomly treated as follows: Group 1 (NT): no treatment; Group 2 (APA-I): airborne particle abrasion (Cobra, Renfert) using 25-μm aluminium-oxide (Al₂O₃)-particles; Group 3 (APA-II): APA with 50-μm Al₂O₃-particles; and Group 4 (APA-III): APA using 110-μm Al₂O₃-particles. Ceramic blocks were duplicated in composite resin. Samples of each pretreatment group were randomly divided into two subgroups depending on the resin cement used for bonding the composite disks to the treated zirconia surfaces. Subgroup 1 (PAN), which was a 10-MDP-containing luting system, used Clearfil Ceramic Primer plus Panavia F 2.0 (Kuraray) and Subgroup 2 (BIF) used Bifix SE (VOCO) self-adhesive cement. After 24 h, bonded specimens were cut into 1 ± 0.1 mm² sticks. MTBS values were obtained using a universal testing machine (cross-head speed = 0.5 mm/min). Failure modes were recorded and the interfacial morphology of the debonded microbars was SEM-assessed. Two-way ANOVA, Student–Newman–Keuls tests, and the step-wise linear regression analysis were performed with the MTBS being the dependent variable (p < 0.05).ResultsDespite the sandblasting granulometry, PAN bonded to air-abraded surfaces attained the highest MTBS and frequently showed mixed fractures. BIF recorded no significant differences in MTBS depending on the conditioning method, and registered the highest rates of premature and adhesive failures.ConclusionsThe 10-MDP-containing luting system seems to be the most suitable to bond zirconium-oxide ceramic, mainly after sandblasting.     

底涂剂的化学处理对二氧化锆陶瓷树脂粘接效果的影响

目的 评估专用底涂剂的化学处理对二氧化锆陶瓷与自粘接型树脂水门汀间粘接效果的影响。方法 2.5 mm厚可切削二氧化锆陶瓷片（Vita InceramYZ）经烧结、研磨、清洗后,一半的陶瓷试件表面在0.3 MPa压力下接受50 μm Al2O3颗粒喷砂处理20 s。使用X射线荧光光谱仪对研磨和喷砂组的陶瓷表面成分进行定性定量分析。研磨和喷砂组的陶瓷片各分为2组：一组直接与自粘接型树脂水门汀（Biscem）进行粘接,另一组经底涂剂（Z Primer Plus）处理后与Biscem进行粘接。各实验组试件再分为两个亚组（n=10）经0、10000次冷热循环后接受剪切粘接 强度测量。使用多因素方差分析对数据进行统计。结果 喷砂后的陶瓷表面会有质量比为8.27%的Al2O3颗粒附着。 与喷砂处理相比,底涂剂处理对冷热循环前粘接强度的提高更加显著。冷热循环前后,未经过底涂剂处理的陶瓷与 树脂间粘接强度的差异无统计学意义（P>0.05）,但经过底涂剂处理后陶瓷与树脂间粘接强度的差异有统计学意义（P<0.05）。结论 底涂剂的化学处理能够显著提高二氧化锆陶瓷与自粘接型树脂水门汀的初期粘接强度,但在耐 久实验条件下其粘接界面不稳定,会出现快速老化。     

Vertical misfit of laser-sintered and vacuum-cast implant-supported crown copings luted with definitive and temporary luting agents

Objectives. This study aimed to evaluate the vertical discrepancy of implant-supported crown structures constructed with vacuum-casting and Direct Metal Laser Sintering (DMLS) technologies, and luted with different cement types. Study Design. Crown copings were fabricated using: (1) direct metal laser sintered Co-Cr (LS); (2) vacuum-cast Co-Cr (CC); and (3) vacuum-cast Ti (CT). Frameworks were luted onto machined implant abutments under constant seating pressure. Each alloy group was randomly divided into 5 subgroups (n = 10 each) according to the cement system utilized: Subgroup 1 (KC) used resin-modified glass-ionomer Ketac Cem Plus; Subgroup 2 (PF) used Panavia F 2.0 dual-cure resin cement; Subgroup 3 (RXU) used RelyX Unicem 2 Automix self-adhesive dual-cure resin cement; Subgroup 4 (PIC) used acrylic/urethane-based temporary Premier Implant Cement; and Subgroup 5 (DT) used acrylic/urethane-based temporary DentoTemp cement. Vertical misfit was measured by scanning electron microscopy (SEM). Two-way ANOVA and Student-Newman-Keuls tests were run to investigate the effect of alloy/fabrication technique, and cement type on vertical misfit. The statistical significance was set at α = 0.05. Results. The alloy/manufacturing technique and the luting cement affected the vertical discrepancy (p < 0.001). For each cement type, LS samples exhibited the best fit (p < 0.01) whereas CC and CT frames were statistically similar. Within each alloy group, PF and RXU provided comparably greater discrepancies than KC, PIC, and DT, which showed no differences. Conclusions. Laser sintering may be an alternative to vacuum-casting of base metals to obtain passive-fitting implant-supported crown copings. The best marginal adaptation corresponded to laser sintered structures luted with glass-ionomer KC, or temporary PIC or DT cements. The highest discrepancies were recorded for Co-Cr and Ti cast frameworks bonded with PF or RXU resinous agents. All groups were within the clinically acceptable misfit range. Key words:Dental alloy, laser sintering, implant-supported prostheses, vertical discrepancy, vertical misfit.     

Novel fabrication method for zirconia restorations: bonding strength of machinable ceramic to zirconia with resin cements

A novel method was developed to fabricate all-ceramic restorations which comprised CAD/CAM-fabricated machinable ceramic bonded to CAD/CAM-fabricated zirconia framework using resin cement. The feasibility of this fabrication method was assessed in this study by investigating the bonding strength of a machinable ceramic to zirconia. A machinable ceramic was bonded to a zirconia plate using three kinds of resin cements: ResiCem (RE), Panavia (PA), and Multilink (ML). Conventional porcelain-fused-to-zirconia specimens were also prepared to serve as control. Shear bond strength test (SBT) and Schwickerath crack initiation test (SCT) were carried out. SBT revealed that PA (40.42 MPa) yielded a significantly higher bonding strength than RE (28.01 MPa) and ML (18.89 MPa). SCT revealed that the bonding strengths of test groups using resin cement were significantly higher than those of Control. Notably, the bonding strengths of RE and ML were above 25 MPa even after 10,000 times of thermal cycling -adequately meeting the ISO 9693 standard for metal-ceramic restorations. These results affirmed the feasibility of the novel fabrication method, in that a CAD/CAM-fabricated machinable ceramic is bonded to a CAD/CAM-fabricated zirconia framework using a resin cement.     

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。     

Adhesion durability of dual-cure resin cements and acid–base resistant zone formation on human dentin

ObjectivesBond durability and resistance to acid-base challenge of dentin with dual-cure resin cement have been rarely investigated. The purpose of this study was to evaluate dentin bond strength and observe the adhesive-dentin interface after acid-base challenge using three different dual-cure resin cements.MethodsThirty dentin surfaces from caries-free human premolars were ground and bonded with one of three dual-cure resin cements: PANAVIA V5 (V5), ESTECEM II (E II) and Rely X Ultimate (RXU) and thermocycled for 0, 5,000 and 10,000 cycles. A microtensile bond strength (μTBS) test was undertaken and the interface of the bonded specimens after acid-base challenge was examined by SEM.ResultsThe μTBS of V5 exhibited a stable bond strength despite thermal cycling while the bond of EII and RXU after 10,000 cycles dropped significantly among all thermal cycle periods (p<0.05). An acid-base resistant zone (ABRZ) was observed in all groups, however, the morphology of the bonded interface differed among the tested cements.ConclusionBonding durability to dentin and ABRZ morphologies differed among the cements evaluated. PANAVIA V5 cement system with tooth primer provided the most reliable bond strength and was best able to resist the acid–base challenge.     

3种树脂水门汀对CAD/CAM全瓷-牙本质剪切强度的比较

目的:评价3种树脂水门汀对CAD/CAM全瓷-牙本质剪切强度的影响。方法:选取新鲜拔除的人磨牙30颗,制备牙本质黏结面,随机分为3组(n=10),分别选用全酸蚀树脂水门汀RelyX ARC、自酸蚀树脂水门汀Clearfil DCBond和自黏结树脂水门汀RelyX Unicem对CAD/CAM硅酸锂玻璃全瓷进行黏结,测试3种树脂水门汀对CAD/CAM全瓷-牙本质的剪切强度,并通过立体显微镜观察牙本质的黏结界面。采用SPSS11.0软件包对数据进行统计学分析。结果:RelyX ARC组的剪切强度为(15.90±6.15)MPa,Clearfil DC Bond组的剪切强度为(14.41±5.07)MPa,而RelyXUnicem组的剪切强度为(23.29±7.39)MPa,与前2组相比有显著性差异(P<0.05)。立体显微镜观察显示,3组黏结断面均位于牙本质与树脂水门汀之间。结论:自酸蚀树脂水门汀及自黏结树脂水门汀与CAD/CAM硅酸锂玻璃陶瓷修复体的黏结强度不低于传统全酸蚀树脂水门汀,且临床操作简便,为临床全瓷黏结提供了更多便利与选择。     

Microtensile Bond Strength and Impact Energy of Fracture of CAD-Veneered Zirconia Restorations

Purpose: With state-of-the-art CAD/CAM technology, the fabrication of large and complex zirconia frameworks is just a click away. On the other hand, veneering of the frameworks is still operator-dependent. The aim of this work was to evaluate CAD veneering of zirconia restorations in terms of zirconia veneer bond strength and impact energy of fracture in a step towards complete automation of the fabrication process.
Materials and Methods: A new CAD/CAM system was used to fabricate a resin replica of the esthetic ceramic required to veneer a zirconia framework. The replica was seated on the zirconia framework and further processed using press-on technology. The bond strength between zirconia and the CAD veneer was evaluated using microtensile bond strength test. The impact energy of fracture of the specimens was also investigated. Manually layered zirconia specimens served as a control (α= 0.05).
Results: There was no significant difference in the microtensile bond strength between zirconia and either of the used veneers (39 MPa). Even though the impact energy of fracture of the CAD-veneered and manually layered specimens was almost identical (0.13 J), the former demonstrated a cohesive fracture of the veneer, while the latter failed by delamination of the veneer ceramic.
Conclusion: CAD veneering is a reliable method for veneering zirconia restorations.     

Influence of cement thickness on resin-zirconia microtensile bond strength

PURPOSE

The aim of this study was to evaluate the influence of resin cement thickness on the microtensile bond strength between zirconium-oxide ceramic and resin cement.

MATERIALS AND METHODS

Thirty-two freshly extracted molars were transversely sectioned at the deep dentin level and bonded to air-abraded zirconium oxide ceramic disks. The specimens were divided into 8 groups based on the experimental conditions (cement type: Rely X UniCem or Panavia F 2.0, cement thickness: 40 or 160 µm, storage: thermocycled or not). They were cut into microbeams and stored in 37℃ distilled water for 24 h. Microbeams of non-thermocycled specimens were submitted to a microtensile test, whereas those of thermocycled groups were thermally cycled for 18,000 times immediately before the microtensile test. Three-way ANOVA and Sheffe''s post hoc tests were used for statistical analysis (α=95%).

RESULTS

All failures occurred at the resin-zirconia interface. Thermocycled groups showed lower microtensile bond strength than non-thermocycled groups (P<.001). Differences in cement thickness did not influence the resin-zirconia microtensile bond strength given the same resin cement or storage conditions (P>.05). The number of adhesive failures increased after thermocycling in all experimental conditions. No cohesive failure was observed in any experimental group.

CONCLUSION

When resin cements of adhesive monomers are applied over air-abraded zirconia restorations, the degree of fit does not influence the resin-zirconia microtensile bond strength.     

Bonding to Zirconia Using a New Surface Treatment

Purpose: Selective infiltration etching (SIE) is a newly developed surface treatment used to modify the surface of zirconia‐based materials, rendering them ready for bonding to resin cements. The aim of this study was to evaluate the zirconia/resin bond strength and durability using the proposed technique. Materials and Methods: Fifty‐four zirconia discs were fabricated and divided into three groups (n = 18) according to their surface treatment: as‐sintered surface (control group), airborne‐particle abrasion (50‐μm aluminum oxide), and SIE group. The zirconia discs were bonded to preaged composite resin discs using a light‐polymerized adhesive resin (Panavia F 2.0). The zirconia/resin bond strength was evaluated using microtensile bond strength test (MTBS), and the test was repeated after each of the following intervals of accelerated artificial aging (AA): thermocycling (10,000 cycles between 5 and 55°C), 4 weeks of water storage (37°C), and finally 26 weeks of water storage (37°C). Silver nitrate nanoleakage analysis was used to assess the quality of zirconia/resin interface. A repeated measures ANOVA and Bonferroni post hoc test were used to analyze the data (n = 18, α= 0.05) Results: There were significant differences in the MTBS values between the three test groups at each of the test intervals (p < 0.001). AA resulted in reduction in the bond strength of the as‐sintered and the particle‐abraded groups (5.9 MPa and 27.4, MPa, respectively). Reduction in the bond strength of these groups was explained by the observed nanoleakage across the zirconia/resin interface. The bond strength of the SIE specimens was stable after completion of AA (51.9 MPa), which also demonstrated a good seal against silver nitrate penetration across the zirconia/resin interface. Conclusion: SIE established a strong, stable, and durable bond to zirconia substrates. Conservative resin‐bonded zirconia restorations are now possible using this new technique.     

一种通用粘接剂对不同CAD/CAM可切削材料的短期粘接成绩

[摘要] 目的 评估一种通用粘接剂对于三种不同类型的CAD/CAM可切削材料的短期粘接成绩。方法 制作氧化钇稳定四方相氧化锆陶瓷,纳米复合陶瓷和二硅酸锂玻璃陶瓷试件各20枚,其中前两者进行喷砂处理,后者进行HF酸蚀处理。各组陶瓷再分为2亚组,分别使用（SBU）或不使用（Ctr）通用粘接剂Single Bond Universal。以上表面处理瓷片与复合树脂柱通过树脂水门汀粘接,制作粘接试件,37℃水储24ｈ后测试剪切粘接强度并记录断裂模式。喷砂处理的氧化锆陶瓷和纳米复合陶瓷,以及酸蚀处理的二硅酸锂玻璃陶瓷通过扫描电镜（SEM）观察表面微观形态。结果SEM观察显示酸蚀处理的二硅酸锂玻璃陶瓷,喷砂处理的氧化锆陶瓷和纳米复合陶瓷相对于粗化处理前呈现出粗糙的表面形态。三种经粗化处理的材料使用通用粘接剂表面处理后,剪切强度较未使用者显著增强。结论 通用粘接剂Single Bond Universal能够增强氧化钇稳定四方相氧化锆陶瓷,纳米复合陶瓷和二硅酸锂玻璃陶瓷三种类型CAD/CAM可切削材料的短期粘接强度。     

玻璃渗透氧化铝陶瓷树脂粘接耐久性的研究

目的分析含有不同类型酸性树脂单体的硅烷偶联剂及不同类型树脂粘接剂的相互组合对玻璃渗透氧化铝陶瓷树脂粘接耐久性的影响。方法使用3种硅烷偶联剂处理玻璃渗透氧化铝陶瓷的表面,使用2种双重固化树脂粘接剂与之粘接。测量试件在0和30 000次冷热循环后的粘接强度。结果冷热循环前,粘接剂A与未硅烷化处理陶瓷间的粘接强度显著低于其他硅烷化处理组,粘接剂A、B与偶联剂B处理的陶瓷间的粘接强度显著低于其与偶联剂A和C的粘接强度。冷热循环30 000次后,粘接剂A与未硅烷化处理陶瓷组的试件全部脱落;而其他硅烷化处理陶瓷组中,只有偶联剂A处理的陶瓷表面与粘接剂A和B间的粘接强度达到了5 MPa以上。结论使用10-甲基丙烯酰氧癸基磷酸酯作为硅烷水解剂的硅烷偶联剂处理的玻璃渗透氧化铝陶瓷能够与不同类型的树脂粘接剂获得较好的粘接耐久性。     

不同核材料与二氧化锆陶瓷树脂粘接耐久性的研究

目的 研究不同类型核材料与二氧化锆陶瓷树脂间的粘接强度及耐久性。方法 二氧化锆陶瓷盘经研磨后通过2种自粘接型树脂水门汀（Clearfil SA Luting和RelyX U100）与不同核材料包括流动型复合树脂核材料、充填型复合树脂、钴铬合金以及牙本质进行粘接,组成个8实验组。每个实验组再分成2个亚组,分别接受0、10 000次冷热循环后进行剪切粘接强度测试。结果 核材料、树脂水门汀材料及老化条件均会对粘接强度产生明显影响（P<0.001）。冷热循环后,只有Clearfil SA Luting与钴铬合金的粘接强度没有明显降低（P>0.05）,并高于其余各核材料组（P<0.05）;Clearfil SA Luting与钴铬合金、流动型复合树脂核材料及充填型复合树脂间的粘接强度均明显高于RelyX U100相对应的粘接强度（P<0.05）,而Clearfil SA Luting和RelyX U100与牙本质间的粘接强度的差异无统计学意义（P>0.05）。结论 不同类型核材料和树脂水门汀材料能够对二氧化锆陶瓷树脂粘接耐久性产生明显影响。     

Resin microtensile bond strength to feldspathic ceramic: hydrofluoric acid etching vs. tribochemical silica coating

This study aimed to compare the microtensile bond strength of resin cement to alumina-reinforced feldspathic ceramic submitted to acid etching or chairside tribochemical silica coating. Ten blocks of Vitadur-alpha were randomly divided into 2 groups according to conditioning method: (1) etching with 9.6% hydrofluoric acid or (2) chairside tribochemical silica coating. Each ceramic block was luted to the corresponding resin composite block with the resin cement (Panavia F). Next, bar specimens were produced for microtensile testing. No significant difference was observed between the 2 experimental groups (Student ttest, P > .05). Both surface treatments showed similar microtensile bond strength values.     

Influence of silanization on early bond strength to sandblasted densely sintered alumina.

OBJECTIVE: The increased popularity of alumina-based restorations has resulted in an interest in proper adhesive techniques to assure a strong and predictable bond to these restorations. This study investigated the early bond strength of three different resin-cement systems to densely sintered alumina (aluminum-oxide ceramic) with and without the use of their corresponding silane coupling agent (silanization). METHOD AND MATERIALS: Ninety samples of densely sintered high-purity aluminum-oxide ceramic were randomly divided into three groups. Composite cylinders were bonded to the ceramic samples with three resin-cement/bonding-agent systems: Noribond DC (NOR), Panavia 21 EX (PAN), and Variolink II (VAR). Each resin-cement/bonding-agent system was used with and without their corresponding silane (SIL) coupling agent (n = 15). After fabrication, the specimens were stored in distilled water for 3 days at room temperature, and shear bond strength was tested. RESULTS: Application of the silane-coupling agent on sandblasted densely sintered alumina did not significantly influence bond strengths with PAN. Silanization significantly improved shear bond strengths with NOR and VAR. NOR-SIL and VAR-SIL revealed the statistically highest values, with NOR-SIL showing the highest mean bond strength of all groups. CONCLUSIONS: Silanization of sandblasted densely sintered alumina had mixed effects on the applied resin cements: It had no effect on the performance of the phosphate-modified resin cement PAN, but significantly improved shear bond strength of the Bis-GMA composite resin cements VAR and NOR. NOR-SIL revealed the highest overall mean bond strength.     

Microtensile bond strength testing of luting cements to prefabricated CAD/CAM ceramic and composite blocks.

OBJECTIVES: To investigate the Microtensile bond strength (microTBS) and failure mode of resin cements bonded to composite and ceramic CAD/CAM blocks following various surface treatments. METHODS: Paradigm composite blocks and Cerec Vitablocs received three surface treatments following the control treatment of surface grinding with 600 SiC grit. (1) Application of adhesive resin (Adh), (2) etching with hydrofluoric acid and silanization (HF+S) or (3) combination of the previous two treatments (HF+S+Adh). Three resin cements (Tetric Flow, Nexus 2, RelyX ARC) were applied to these surfaces and built-up in layers. After 24 h water storage at 37 degrees C, the non-trimming version of microTBS test was used to produce 1 mm(2) microbars. The Microbars were subjected to a tensile load using a modified testing device. The broken specimens were examined with a stereomicroscope and SEM to determine the failure mode. RESULTS: All control and adhesive treated groups of the ceramic substrate showed premature debonding during cutting. The overall mean microTBS for the three resin cements bonded to ceramic following HF+S and HF+S+Adh surface treatment, was 27 and 29.2 MPa and for the resin cements bonded to composite substrate was 42.3 and 54.2 MPa, respectively. The mode of failure was 98% adhesive with composite as a substrate and 68% mixed failures with ceramic as a substrate. CLINICAL SIGNIFICANCE: CAD/CAM restorations fabricated from processed composite blocks may have advantage over the ceramic blocks with regard to the higher bond strength with resin cements.     

Shear bond strengths of various luting cements to zirconia ceramic: surface chemical aspects

Objectives

To measure the shear bond strengths of various luting cements to a sandblasted zirconia ceramic and to determine the surface energy parameters of the luting cements.

Methods

Two conventional glass ionomer cements, two resin-modified glass ionomer cements, two compomer cements, and two adhesive resin cements were prepared and bonded to sandblasted zirconia (Lava). All bonded specimens were stored in water at 37 °C for 48 h and then half of them additionally thermocycled 10,000 times prior to the shear bond strength test (n = 10). Surface roughness (R_a) values and surface energy parameters of the eight luting cements and polished zirconia ceramic were evaluated using a profilometer and contact angle measurements, respectively (n = 10). The bond strength and surface roughness data were statistically analysed using non-parametric and parametric procedures, respectively (α = 0.05). Relationships between surface energy parameters and measured shear bond strengths were investigated using the Spearman rank correlation test.

Results

Panavia F 2.0 and Principle produced higher bond strengths than the other cements, with no significant changes before and after thermocycling. Fuji I, Ketac Cem Easymix, and Ionotite F yielded near-zero or zero values after thermocycling. All debonded specimens showed adhesive failure. Mean R_a values ranged from 0.104 to 0.167 μm. We found the base (hydrogen bond accepting) components of the luting cements significantly affected the bond strengths both before and after thermocycling.

Conclusion

It is recommended that the surface energy parameters of luting cements be considered in evaluating their adhesive properties with zirconia ceramic.