Shear Bond Strength of Four Resin Cements Used to Lute Ceramic Core Material to Human Dentin

Purpose: This study evaluated the effect of four resin cements on the shear bond strength of a ceramic core material to dentin. Materials and Methods: One hundred twenty molar teeth were embedded in a self‐curing acrylic resin. The occlusal third of the crowns were sectioned under water cooling. All specimens were randomly divided into four groups of 30 teeth each according to the resin cement used. One hundred twenty cylindrical‐shaped, 2.7‐mm wide, 3‐mm high ceramic core materials were heat‐pressed. The core cylinders were then luted with one of the four resin systems to dentin (Super‐Bond C&B, Chemiace II, Variolink II, and Panavia F). Half of the specimens (n = 15) were tested after 24 hours; the other half (n = 15) were stored in distilled water at 37°C for 1 day and then thermocycled 1000 times between 5°C and 55°C prior to testing. Shear bond strength of each specimen was measured using a universal testing machine at a crosshead speed of 1 mm/min. The bond strength values were calculated in MPa, and the results were statistically analyzed using a two‐way analysis of variance (ANOVA) and Tukey HSD tests. Results: The shear bond strength varied significantly depending on the resin cement used (p < 0.05). The differences in the bond strengths after thermocycling were not remarkable as compared with the corresponding prethermal cycling groups (p > 0.05). Significant interactions were present between resin cement and thermocycling (p < 0.05). After 24 hours, the specimens luted with Variolink II (5.3 ± 2.2 MPa) showed the highest shear bond strength, whereas the specimens luted with Chemiace II (1.6 ± 0.4 MPa) showed the lowest. After thermocycling, the bond strength values of specimens luted with Chemiace II (1.1 ± 0.1 MPa) and Super‐Bond C&B (1.7 ± 0.4 MPa) decreased; however, this was not statistically significant (p > 0.05). The increase in the shear bond strength values in the Panavia F (4.5 ± 0.7 MPa) and Variolink II (5.5 ± 2.1 MPa) groups after thermocycling was also not statistically significant (p > 0.05). Conclusion: Variolink II and Panavia F systems showed higher shear bond strength values than Chemiace II and Super‐Bond C&B. They can be recommended for luting ceramic cores to dentin surfaces.     

Adhesive Bonding of Resin Composite to Various Ni‐Cr Alloy Surfaces Using Different Metal Conditioners and a Surface Modification System

Purpose: This study evaluated the effect of three metal conditioners [Metal Photo Primer^® (MPP), Cesead II Opaque Primer^® (OP), Targis Link^® (TL)], and one surface modification system [Siloc^® (S)] on the shear bond strength (SBS) of a prosthetic composite material to Ni‐Cr alloy. Materials and Methods: Rivet‐shaped specimens were cast, and three surface treatments were evaluated: Polishing (P); sandblasting with either 50 μm (50SB) or 250 μm (250SB) Al₂O₃. All products were applied to half of the specimens, while the other half remained without the materials. Veneering resin composite (8‐mm diameter, 2‐mm thick) was applied and light‐exposed for 90 seconds in a laboratory light‐curing unit. The specimens were stored in water at 37°C for 24 hours, and half were subjected to 500 thermal cycles consisting of water baths at 4°C and 60°C. All specimens were submitted to SBS test (0.5 mm/min) until failure. Failure patterns were determined using optical and scanning electron microscope (SEM) analysis. Data were analyzed by ANOVA and post hoc Tukey's test (preset alpha of 5%). Results: The SBS values of OP and TL groups were higher than those of MPP and S within the 50SB treatment (p < 0.05). No significant difference in SBS was noted between OP and TL as well as between MPP and S. On the other hand, no significant differences were found among conditioners within the 250SB group (p > 0.05). The SBS values of MPP, OP, and S from the 250SB group were higher than those from 50SB (p < 0.05). No significant difference in SBS was noted among most groups with conditioners after thermocycling. The only exception was observed for MPP, which showed an increase in SBS after thermocycling (p < 0.05). Differences in SBS were noted among the groups with conditioners (p < 0.05), and no significant difference in SBS was noted between TL and OP groups, which showed the highest values among all within the P group. No significant difference was noted between MPP and S. Debonded surfaces showed adhesive failures predominantly located between metal surface and opaque resin. Conclusions: The OP and TL conditioners and surface sandblasting with 250 μm Al₂O₃ promoted the highest SBS between resin and the Ni‐Cr metal surface.     

3种树脂粘接水门汀与铸造纯钛粘接强度研究

目的：研究3种复合树脂粘固剂与铸造纯钛的粘接强度。方法：用牙科铸钛的方法制作直径分别为4mm和5mm的钛棒,切割成长度为4mm的小钛片。2种规格的钛片配对粘接面用400～1200目碳化硅砂纸在流水下打磨抛光,使之呈均匀一致的平面。50μm氧化铝喷砂,另一组表面不喷砂作为对照,分别使用Super-BondC＆B、Panavia F、Rely X Unicem 3种复合树脂粘固剂粘接。扫描电镜观察喷砂前后铸造纯钛的表面形态。复合树脂粘接剂固化后经37℃恒温水浴24h以及5000次5～55℃冷热循环,测试剪切强度。用SAS的ANOVA过程对各组数据进行分析。结果：喷砂前后纯钛与Panavia F的剪切强度最高,分别为（26.62±3.40）MPa、（23.71±5.28）MPa;5000次冷热循环后,喷砂组的铸造纯钛与Panavia F的剪切强度最高（27.12±8.68）MPa;未喷砂的铸造纯钛与Super-Bond C＆B、Rely X Unicem的粘接强度最低,并且有12.5%的脱落率。结论：本实验结果表明喷砂可以提高Super-Bond C＆B、Panavia F、Rely X Unicem的粘结力和粘结耐久力。不喷砂时,Panavia F与铸造纯钛之间能获得较高的粘接强度和良好的粘接耐久性,喷砂以后优势不再明显。     

冷热循环对不同金属与树脂粘接剂粘接强度的影响

目的：冷热循环对不同金属与树脂粘接剂粘接强度的影响。方法：铸造直径分别为4mm和5mm的镍铬合金和纯钛,切割成长度为3mm的标本。2种规格的同种金属标本配对,金属表面经50μmAlzO3喷砂,涂布Al—loy Primer,使用Super—BondC＆B和PanaviaF2种粘接剂粘接。固化后经37℃恒温水浴24h以及10000次冷热循环,测试剪切粘接强度。用spssl7．0统计软件进行统计分析。结果：10000次冷热循环后,镍铬合金与Super—BondC＆B、纯钛与PanaviaF粘接强度显著提高（P〈O．01）,其余各组没有统计学差异。结论：粘接剂的种类对冷热循环前后的粘接强度没有明显影响,金属的种类对冷热循环前后的粘接强度没有明显影响,但是不同金属和不同粘接剂的配伍组合在冷热循环前后的粘接强度变化有统计学意义。     

Fatigue of Resin Cement–Base Metal Alloy Bond Strength

Purpose Strong durable bonds between resin cements and metal alloys are critical to the success of resin-bonded, resin-veneered, or resin-retained prostheses. However, few comprehensive, comparative evaluations of materials or the fatigue effects of thermal cycling have been reported. The rate of strength loss may be a more important predictor of long-term success than bond strength. The purpose of this study was to investigate the effects of artificial aging by thermal cycling and resin cement type on the bond strengths to a base metal alloy. Materials and Methods This study investigated the effect of the number of thermal cycles (0, 1, 10, 100, 1,000 and 10,000) on the bond strengths of nine fixed prosthodontic resin cements. Specimens were assigned randomly to thermal cycle number/cement type test groups. Cylinders of a base metal alloy were bonded in an end-to-end configuration. One end of each bonded specimen was insulated, and the specimen was thermal cycled. Then, the bonds were tested in shear and bond strengths calculated. Results Two-way ANOVA revealed that the effects of cement type, the number of thermal cycles, and their interaction all significantly affected bond strength (p < .0001). Multiple range analysis showed that some cements had significant trends to lose bond strength with thermal cycling (p < .05), while others did not (p > .05). Conclusions Both the type of resin cement and the amount of thermal cycling influenced bond strength to a base metal alloy. Some materials displayed more rapid loss of bond strength than others.     

Durability of Adhesion between Feldspathic Ceramic and Resin Cements: Effect of Adhesive Resin,Polymerization Mode of Resin Cement,and Aging

Purpose : Adhesive cementation is an important step for restorations made of feldspathic ceramic as it increases the strength of such materials. Incorrect selection of the adhesive resin and the resin cement to adhere to the ceramic surface and their durability against aging can affect the adhesion between these materials and the clinical performance. This study evaluated the effect of adhesive resins with different pHs, resin cements with different polymerization modes, and aging on the bond strength to feldspathic ceramic. Materials and Methods : One surface of feldspathic ceramic blocks (VM7) (N = 90) (6.4 × 6.4 × 4.8 mm³) was conditioned with 10% hydrofluoric acid for 20 seconds, washed/dried, and silanized. Three adhesive resins (Scotchbond Multi‐Purpose Plus [SBMP], pH: 5.6; Single Bond [SB], pH: 3.4; and Prime&Bond NT [NT], pH: 1.7) were applied on the ceramic surfaces (n = 30 per adhesive). For each adhesive group, three resin cements with different polymerization modes were applied (n = 10 per cement): photo‐polymerized (Variolink II base), dual polymerized (Variolink II base + catalyst), and chemically polymerized (C&B). The bonded ceramic blocks were stored in water (37°C) for 24 hours and sectioned to produce beam specimens (cross‐sectional bonded area: 1 ± 0.1 mm²). The beams of each block were randomly divided into two conditions: Dry, microtensile test immediately after cutting; TC, test was performed after thermocycling (12,000×, 5°C to 55°C) and water storage at 37°C for 150 days. Considering the three factors of the study (adhesive [3 levels], resin cement [3 levels], aging [2 levels]), 18 groups were studied. The microtensile bond strength data were analyzed using 3‐way ANOVA and Tukey's post hoc test (α= 0.05). Results : Adhesive resin type (p < 0.001) and the resin cement affected the mean bond strength (p= 0.0003) (3‐way ANOVA). The NT adhesive associated with the chemically polymerized resin cement in both dry (8.8 ± 6.8 MPa) and aged conditions (6.9 ± 5.9 MPa) presented statistically lower bond strength results, while the SBMP adhesive resin, regardless of the resin cement type, presented the highest results (15.4 to 18.5 and 14.3 to 18.9 MPa) in both dry and aged conditions, respectively (Tukey's test). Conclusion : Application of a low‐pH adhesive resin onto a hydrofluoric acid etched and silanized feldspathic ceramic surface in combination with chemically polymerized resin cement did not deliver favorable results. The use of adhesive resin with high pH could be clinically advised for the photo‐, dual‐, and chemically polymerized resin cements tested.     

Comparison of the Flexural Strength of Five Adhesive Resin Cements

Statement of Problem : The increased use of adhesive resin cements in bonded prosthetic restorations has led to restorations debonding under function. Purpose : This investigation evaluated the differences in the flexural strength of new adhesive resin cements as a function of specimen age and storage condition. Materials and Methods : Four new dual‐cure cements were compared to C/B Metabond. Twenty specimens of each of the five cements were prepared in a rectangular glass mold (25 × 2 × 2 mm). The new cements were light‐activated with a 550 mW/cm² lamp for 80 seconds on both the top and bottom surfaces. The auto‐cured cement was allowed to set according to manufacturer's directions. Half the specimens were tested immediately after curing while the other half were stored in distilled water at 37°C for 30 days. A three‐point bending test was performed using an Instron at a crosshead speed of 1 mm/min. The results were analyzed by analysis of variance and Scheffé tests ( p < 0.05) to examine the effect of specimen age and storage condition. Results : RelyX ARC exhibited a significantly higher flexural strength compared with Calibra and Panavia F when tested immediately. The standard cement, C/B Metabond, deformed and did not fracture at the immediate test time. After storage, the flexural strength had significantly improved from the immediate test time for Calibra, Cement‐It, Panavia F, and C/B Metabond. However, there were no significant differences in the flexural strength among the cements when tested after 30 days in water at 37°C. Conclusion : Immediately after curing, these new adhesive resin cements are not equivalent, as evidenced by the significant variability in the measured flexural strength. The distinctions among the cements diminish after aging in water, which may be due to residual polymerization or a plasticizing effect from water absorption. Clinical Significance : When light‐cured, all the new adhesive resin cements have greater early strengths than the auto‐cured cement; however, the wide variation in immediate bending strength suggests that some cements may be more appropriate for use in high‐stress clinical situations such as resin‐bonded fixed partial dentures.     

6种复合树脂粘接剂与纤维增强型复合树脂根管桩的粘接强度研究

目的评价6种复合树脂粘接剂与带有半渗透网状复合基质的纤维增强型复合树脂根管桩的粘接强度。方法实验分为6组,分别为纤维增强型复合树脂根管桩和6种复合树脂粘接剂模块,每组7个样本。用粘接树脂活化剂处理各组根管桩表面5min,将粘接剂模块粘接到根管桩表面并固化,37℃下储存各组样本20h后,万能实验机进行剪切粘接强度测定。结果6种不同复合树脂粘接剂与纤维增强型复合树脂根管桩粘接后,各组根管桩表面剪切粘接强度之间的差异无统计学意义（F=2.32,P=0.45）。结论6种复合树脂粘接剂均适用于纤维增强型复合树脂根管桩的粘接。     

Evaluation of Adhesive and Compressive Strength of Glass Ionomer Cements

The aim of the study was to assess, compare and evaluate the adhesive strength and compressive strength of different brands of glass ionomer cements to a ceramometal alloy. (A) Glass ionomer cements: GC Fuji II (GC Corporation, Tokyo), Chem Flex (Dentsply DeTrey, Germany), Glass ionomer FX (Shofu-11, Japan), MR dental (MR dental suppliers Pvt Ltd, England). (B) Ceramometal alloy (Ni–Cr: Wiron 99; Bego, Bremen, Germany). (C) Cold cure acrylic resin. (E) Temperature cum humidity control chamber. (F) Instron Universal Testing Machine. Four different types of Glass ionomer cements were used in the study. From each type of the Glass ionomer cements, 15 specimens for each were made to evaluate the compressive strength and adhesive strength, respectively. The 15 specimens were further divided into three subgroups of five specimens. For compressive strength, specimens were tested at 2, 4 and 12 h by using Instron Universal Testing Machine. To evaluate the adhesive strength, specimens were surface treated with diamond bur, silicone carbide bur and sandblasting and tested under Instron Universal Testing Machine. It was concluded from the study that the compressive strength as well as the adhesive bond strength of MR dental glass ionomer cement with a ceramometal alloy was found to be maximum compare to other glass ionomer cements. Sandblasting surface treatment of ceramometal alloy was found to be comparatively more effective for adhesive bond strength between alloy and glass ionomer cement.     

The Bond Strength of an Adhesive Resin Luting Cement to a Variety of Surface Treatments of a High-Palladium Copper Alloy

Purpose This study evaluated the tensile bond strength of a bisphenol glycidyl methacrylate (Bis-GMA) resin luting cement with four different surface treatments of a high Pd-Cu alloy. Materials and Methods For each surface treatment type (tin-plated, porcelain furnace oxide, air-abraded, and finished-only), 15 opposing half-dumbbell-shaped samples were cast and prepared in new Pd?Cu alloy. Samples were luted with a Bis-GMA resin luting cement at a film thickness of 80 μm using a custom alignment apparatus. Samples were stored in distilled water at 37°C for 24 hours, thermocycled for 1,000 cycles, and then stored for 30 days in distilled water at 37°C. Samples were then subjected to fracture in tension at a loading rate of 0.5 cm/min with the bond strengths calculated in megapascals (MPa). The fractured surfaces were examined using stereomicroscopy and scanning electron microscopy at various magnifications ranging from 5.5x to 500x to determine the type of bond failure (adhesive, cohesive, or mixed). Results Tensile bond strengths (mean ± SD MPa) were: tin-plated, 30 ± 15.7; porcelain furnace oxide, 23 ± 8.6; air-abraded, 8 ± 8.1; and finished-only, 4 ± 4.5. Statistical analysis of the tensile bond values using an ANCOVA and Tukey's multiple comparison test at a significance level of 0.05 indicated that there was no difference between the tin-plated and the furnace oxide groups, as well as between the air-abraded and the furnace oxide groups. However, there was significant difference between the tin-plated, the air-abraded, and the finished-only groups. The observed bond failures were predominantly mixed and cohesive in nature with only one adhesive failure. Conclusions There was no significant difference in the tensile bond strengths between the tin-plated group or the porcelain furnace oxide surface group. This suggests that the less-technique-sensitive porcelain furnace oxide surface treatment offers an alternative for achieving high metal-resin bonds to a high Pd?Cu alloy.     

铸造纯钛与树脂水门汀粘结界面疲劳强度的研究

目的：本实验通过体外循环加载模拟口内受力,研究不同的树脂水门汀与铸造纯钛之间粘结界面疲劳强度,以及冷热循环对疲劳强度的影响,为临床应用提供实验依据。方法：用φ5mm×5mm的圆柱形小钛段与φ4mm×2mm小钛片48对分别用Super-Bond C＆B和Panavia F粘接,粘接前粘接面用Alloy Primer预处理,将以上每组中的一半样品置于37℃水浴箱内24h,另一半样品水储24h后再进行5000次冷热循环（5℃←→55℃,浸渍时间为30s）。将样本固定于振动动态测试系统上进行疲劳测试,试验波形为正弦波,应力比R=0,频率为4Hz,测定参照升降法,将疲劳试验结果与之前静载剪切强度测试结果进行对比分析。结果：疲劳极限远小于静载剪切强度值,冷热循环对疲劳强度没有明显影响。疲劳极限值与剪切强度值呈正相关（P〈0.01）。结论：铸造纯钛表面经Alloy Primer处理后与2种树脂水门汀粘固后能耐受106次循环加载的疲劳极限约为静载剪切强度的15%。     

Surface Bond Strength in Nickel Based Alloys

Bonding of ceramic to the alloy is essential for the longevity of porcelain fused to metal restorations. Imported alloys used now a days in processing them are not economical. So this study was conducted to evaluate and compare the bond strength of ceramic material to nickel based cost effective Nonferrous Materials Technology Development Center (NFTDC), Hyderabad and Heraenium S, Heraeus Kulzer alloy. An Instron testing machine, which has three-point loading system for the application of load onto the specimen was utilized for analyzing bond strength of both alloys. Student t test was conducted and t value obtained was 0.644, and the mean value of flexural bond strength of indigenous alloy is 81.75 with standard deviation of 12.25 and of imported alloy is 84.42 with standard deviation of 10.35, indicating that there was no significant difference between the two alloys. Due to ever increasing cost of imported non-precious alloy the need for a cost-effective replacement was fulfilled by indigenous NFTDC alloy.     

The Effect of Recasting on Bond Strength between Porcelain and Base‐Metal Alloys

Purpose: Long‐term success of metal ceramic restorations depends on metal ceramic bond strength. The purpose of this study was to determine whether recasting of base‐metal alloys has any effect on metal ceramic bond strength. Materials and Methods: Super Cast and Verabond base‐metal alloys were used to cast 260 wax patterns. The alloy specimens were equally divided into five groups and cast as: group A 0.0%, B 25%, C 50%, D 75%, and E 100% once‐cast alloy. Each group was divided into two subgroups: the first group was cast with Super Cast and the second with Verabond. In each subgroup half of the cast alloys were veneered with Vita VMK 68 and the others with Ceramco 3. Results: Recasting decreased bond strength (p < 0.006) when used for 50% once‐cast alloy. Group E with 100% new Super Cast alloy veneered with Vita VMK 68 porcelain had the highest bond strength (30.75 ± 9.58 MPa), and group B including 25% new and 75% recast Super Cast alloy veneered with the same porcelain had the lowest bond strength (21.72 ± 5.19 MPa). Conclusions: By adding over 50% once‐cast alloy in base‐metal alloys, metal‐ceramic bond strength decreases significantly.