Tensile bond strength of four denture resins to porcelain teeth with different surface treatment

PURPOSE

This study evaluated the bond strength between porcelain denture teeth (Bioblend 43D) and four different polymerized denture resins (Lucitone 199, Palapress, Acron MC, Triad) with and without a bonding agent and after four different types of surface treatment (polished, HF etched, sandblasted, air-abraded).

MATERIALS AND METHODS

Central incisor porcelain denture teeth were divided into 32 groups of 5 each. Tensile bond strength (MPa) was determined using a testing machine at crosshead speed of 0.5 mm/min. Mean and standard deviation are listed. Data were analyzed by two-way ANOVA. Means were compared by Tukey-Kramer intervals at 0.05 significance level.

RESULTS

All surface treatment increased bond strength compared to polished surface and the highest bond strength was found with Palapress resin with etched porcelain surface (8.1 MPa). Bonding agent improved the bond strength of all denture resins to porcelain teeth. Superior bonding was found with Palapress and air-abraded porcelain (39 MPa).

CONCLUSION

Resins with different curing methods affect the bond strength of porcelain teeth to denture bases. Superior bonding was found with auto-polymerized resin (Palapress). Application of ceramic primer and bonding agent to porcelain teeth with and without surface treatment will improve the bond strength of all denture resins to porcelain teeth.     

Wear mechanisms of resin and porcelain denture teeth

The aim of this investigation was to describe the wear mechanism in occlusal contact areas of porcelain and acrylic resin denture teeth opposing different dental materials. A 55-year-old man with earlier extensive wear was given two complete dentures, as identical as possible, in the upper jaw. One of the dentures had diatoric teeth in cross-linked resin and the other denture had diatoric teeth in porcelain. The dentures were antagonizing a new gold-acrylic fixed bridge from 46 to 36. Two contralateral segments of the bridge were made as removable double crowns. The removable segments were made in different materials: gold, porcelain, light-cured resin, and heat-cured resin. Wear of the denture teeth was studied by scanning electron microscopy on replica models made after 1 and 2 months of antagonizing contact with the various materials. Wear of both porcelain and modern cross-linked resin teeth was mainly a fatigue type of wear. Abrasion was observed when hard particles were assumed to be part of the wear debris.     

Three cements used for orthodontic banding of porcelain molars

OBJECTIVE: Objectives of this study were to (1) compare the mean shear-peel bond strength of orthodontic bands luted to porcelain molar denture teeth with glass ionomer cement (GIC), resin-modified glass ionomer cement (RMGIC), or compomer cement; (2) assess the amount of cement remaining on the teeth after debanding; and (3) compare the survival times of the cemented bands subject to mechanical fatigue. MATERIALS AND METHODS: Sixty banded denture teeth (20 per cement group) were used to determine shear-peel bond strength, and 30 banded denture teeth (10 per cement group) were used to determine fatigue survival time. Shear-peel bond strength was determined with a universal testing machine, and groups were compared by one-way analysis of variance. The amount of cement remaining on the teeth after band removal was scored, and a chi-square test was used to compare groups. Fatigue testing was conducted in a ball mill, and a log-rank test was used to compare differences in survival times. RESULTS: No differences were found in mean shear-peel bond strength among the three groups. The amount of cement remaining on the teeth varied between the compomer and GIC groups (P = .01), with more compomer cement remaining relative to GIC. The mean survival times of bands cemented with compomer or RMGIC were longer than for bands cemented with GIC (P < .001). CONCLUSION: The findings show that on porcelain teeth the band cements have comparable mean shear-peel bond strengths, but that band retention with RMGIC and compomer cement are superior to GIC when subjected to simulated mechanical fatigue.     

Evaluation of methods for polishing porcelain denture teeth

According to the dentists' evaluations of the polished occlusal surfaces, methods 2, 4, and 5 were most effective. However, additional factors, such as the reduction of tooth thickness, the length of the polishing time, and the cost, should be considered when selecting the “best” over-all polishing method for a specific purpose. In addition, this study was limited to five polishing methods. Undoubtedly, others in use may be more effective for polishing porcelain denture teeth.     

两种不同材料的瓷嵌体用于后牙修复的临床效果比较

目的 比较在计算机辅助设计/计算机辅助制作(CAD/CAM)下IPS e.max全瓷高嵌体及LavaUltimate优韧瓷高嵌体用于修复后牙缺损的临床治疗效果。方法 临床完成IPS e.max全瓷高嵌体75个，LavaUltimate优韧瓷高嵌体62个，随访观察6个月、1年、2年、3年，参考美国公共健康会（USPHS）标准,对其临床效果进行观察。结果 IPSe.max全瓷高嵌体的颜色优于LavaUltimate优韧瓷高嵌体；而Lava Ultimate优韧瓷高嵌体的修复体完整性优于IPS e.max全瓷高瓷嵌体。结论 两种材料瓷嵌体用于后牙修复的临床效果没有显著差异，优选哪种材料取决于患者的喜好。关注修复体完整性的患者建议优选Lava Ultimate优韧瓷，关注高嵌体的颜色的患者建议优选IPSe.max全瓷。     

缺失前牙烤瓷桥的美学修复

目的：探讨前牙烤瓷桥修复的美学效果。方法：采用烤瓷桥对102例患者缺失的前牙进行修复并对其满意度进行调查分析。结果：102例中对美观的满意度达96．10％，形态的满意度达92．20％。结论：缺失前牙烤瓷桥具有良好的美学修复效果。     

SEM observations of porcelain Y-TZP interface

ObjectivesThe metastability of the tetragonal phase of yttria tetragonal zirconia polycrystalline (Y-TZP) ceramics is a cause for concern in dental crown and bridge applications. One specific problematic area is the nature of the interface between the veneering porcelain and the Y-TZP framework and whether the associated preparation procedures and reactions result in a reduction of the stability of the zirconia.MethodsTo investigate this aspect, high-resolution SEM observations were made of polished and etched (HF content gel) cross-sections of the interface area. Dry and moist veneering porcelain powders were built up on the zirconia base.ResultsIn some instances the zirconia grains at the interface appear to show multiplicity of subgrain faceting whereas in other instances they do not. The latter indicate destabilisation of the tetragonal phase occurs and in addition that the porcelain veneering material wets and some dissolution of the Y-TZP occurs.SignificanceThese results and their relevance to the long-term stability of the interface adhesion to the veneering porcelain as well as possible tetragonal to monoclinic crystal transformations at the interface are discussed.     

The effect of polishing porcelain laminates on induced I-Bar wear.

Partial-coverage porcelain laminate restorations may successfully be used to create undercuts for removable partial denture abutment teeth. If recontouring of such restorations becomes necessary after placement, surface polishing would be necessary prior to removable partial denture fabrication. In this study the wear of luted porcelain laminates, which received a polished surface treatment and contacting I-bar clasps, was quantified over a simulated 2-year period when subjected to removable partial denture placement and removal. Scanning electron photomicrographs and computer imaging were used for wear measurement. These data were compared to previously recorded data on wear of I-bar tips against human enamel and glazed, luted, porcelain-laminate restorations under the same experimental conditions. No measurable wear was observed on any of the laminate specimens. I-bar clasps tested against the glazed laminate restorations exhibited the greatest mean wear, and those tested against the polished laminates exhibited the least mean wear.     

Dynamic viscoelastic properties of models composed of posterior denture teeth and denture base resin

The purpose of this investigation was to compare the dynamic viscoelastic properties of various models composed of denture teeth and heat-cured denture base resin. The specimens were porcelain and resin teeth mounted in denture base resin. Compressive dynamic stiffness and phase differences were measured with a viscoelastic spectrometer. Measurements of the viscoelastic frequency spectrum based on the fast Fourier transform of displacement to applied random forces were analyzed with a spectrum analyzer. The stiffness of the specimens was independent of the frequency. The stiffness of the porcelain specimens was higher than that of the resin ones measured under the same conditions. The phase lag of the specimens was dependent on the frequency. The phase lag of the porcelain specimens was lower than that of the resin ones measured under the same conditions. This study suggested that the acrylic resin teeth had greater toughness and higher shock-absorbing ability than the porcelain teeth, and that the porcelain teeth were more brittle than the acrylic resin ones, whether the teeth were isolated or in dentures.     

含钛镍铬合金烤瓷冠修复老年人牙体牙列缺损的临床评价

目的:评价含钛镍铬合金烤瓷冠修复老年牙体牙列缺损的临床应用效果.方法:随访2年对比观察96例老年病人88件含钛镍铬合金(Tilite)烤瓷冠(实验组)和86件Ni-Cr合金烤瓷冠(对照组)的颜色、边缘密合、颈缘灰线、瓷折断折裂、过敏反应等情况.结果:两组在颜色、边缘密合、颈缘灰线、瓷折断折裂等方面未见显著差异(P＞0.05);实验组无过敏反应,而对照组发生3例(6.25%)组织过敏反应.结论:两组临床表现基本相似,但含钛镍铬合金(Tilite)烤瓷冠生物相容性优于Ni-Cr合金烤瓷冠.     

Color stability of different denture teeth materials: an in vitro study.

The aim of this in vitro study was to compare the color stability of commercially available porcelain, reinforced acrylic, and conventional acrylic denture teeth materials used in removable prostheses. Two brands of porcelain (Unilux-Enta Lactona-Holland and Vivoperl-Ivoclar-Liechtenstein), 2 brands of reinforced acrylic (Optodent-Bayer-Germany and Ivolek-Ivoclar-Liechtenstein), and 2 brands of conventional acrylic (Isodent-Güney Di? Deposu-Turkey and Samed-Turkey), were made, for a total of 6 different denture teeth groups. Denture teeth were subjected to 3 staining solutions (filtered coffee, tea, and cola) and distilled water. From each group of denture teeth, 4 sets of maxillary anterior denture teeth were immersed in each of the 4 solutions. The color values of denture teeth were measured colorimetrically with the Gardner XL 20 Tristimulus Colorimeter (Gardner Lab. Inc., Bethesda, Maryland, USA). Color changes were characterized in the CIEL*a*b* color space. Color change values were determined after 1 day, 1 week, 2 weeks, and 4 weeks. The color difference values were calculated and then evaluated by two-way ANOVA statistically. The filtered coffee solution was found to be more chromogenic than the other 2 staining solutions, while porcelain denture teeth materials were more color stable. Assuming the color change of deltaE* < 1.0 as a discernible limit and deltaE* = 3.3 as an acceptable value, the filtered coffee, tea, and cola had slight staining effects on all 6 groups of denture teeth.     

Changing Smiles Through Multidisciplinary Approach with Predictable Aesthetics: A Case Report

This clinical report describes a multidisciplinary approach for the rehabilitation of a young patient with mobile and missing front teeth. The objectives of the treatment were to eliminate tooth mobility and replacing missing tooth, while enhancing aesthetics and restoring masticatory function. Treatment included placement of endodontic stabilizer and rehabilitating missing tooth with fixed partial denture and gingival porcelain to satisfy the patient’s aesthetic and functional expectations.

     

烤瓷贴面治疗变色牙的临床疗效

目的：观察烤瓷贴面治疗变色牙的临床疗效。方法：应用烤资面法治疗116个变色牙；并以复合树脂贴面治疗106个变色牙作对照。跟踪观察2年，比较其临床效果。结果：按颜色、外形、功能、感觉进行检查，用烤瓷贴面治疗者2年疗效优于84牙（72．4％），一般32牙（27．6％）。用复合树脂治疗者2年疗效优66牙（62．26％），一般25牙（23．58％），失败15牙（14．15％）。结论：烤瓷贴面治疗变色牙的2年临床疗效较复合树脂贴面好，但远期疗效有待进一步研究。     

超薄瓷贴面的临床应用进展

超薄瓷贴面的临床应用具体是指在没有或者极少量的牙齿预备基础上仅通过0.3~0.5 mm厚的瓷贴面来改善牙齿的美学效果,已成为前牙美学修复的主流,因其对牙齿的损伤极小而备受患者青睐,临床医生也越来越关注超薄瓷贴面的修复过程及远期疗效。该文将从发展过程、适应证、牙体预备以及瓷材料与粘接剂的选择方面对超薄瓷贴面的临床应用现状进行详细论述。     

3种金属烤瓷冠修复后龈沟液中白细胞介素-8水平动态测定

目的探讨镍铬合金、钴铬合金、金合金3组金属烤瓷冠修复前后不同时期龈沟液（GCF）内白细胞介素-8（IL-8）水平变化,了解这3种金属烤瓷冠在不同时期对牙龈的刺激程度。方法临床随机选择3种金属烤瓷冠修复患者共45例,每组各15例,测定在修复前以及修复后1、3、6个月GCF量,并采用双抗体夹心酶联免疫吸附法检测同期GCF中IL-8总量、IL-8含量。结果镍铬合金烤瓷冠在修复1、3、6个月后GCF量、IL-8总量与修复前相比差异均有统计学意义（P＜0.05）。钴铬合金、金合金烤瓷冠在修复3个月后回复到修复前水平。3种金属烤瓷冠IL-8含量在不同时期差异均无统计学意义。结论IL-8参与炎症的免疫调节,可作为评价不同金属烤瓷冠对牙龈组织刺激程度的指标,不同合金烤瓷冠内冠材料对牙龈存在不同的长期刺激,临床金属烤瓷冠修复时对内冠材料的选择应予以关注。     

Thermal cycling distortion of porcelain fused to metal fixed partial dentures

Statement of problem. The initial fit of porcelain fused to metal restorations deteriorates during the firing cycle of porcelain. Purpose. This study evaluated thermal cycling distortion of 3-unit porcelain fused to metal frameworks at different firing stages. Material and methods. A master model was designed to represent the 2 abutments of a 3-unit fixed partial denture replacing a missing mandibular molar. Standard techniques were used to fabricate 10 castings. Half of the copings were cast in a Ni-Cr alloy and the other half in a Pd-Cu alloy. Framework distortion was measured by means of inner fit changes, horizontal linear measurements of the framework length, and vertical fit changes of each retainer. Measurements were made (1) initially, (2) after degassing firing, and (3) after glaze firing. Differences between the firing cycles created distortion values of the retainers in 3 dimensions. Repeated measures ANOVA was used to analyze data statistically. Results. Measured differences between the 2 firing stages ranged from –47 to 81.7 μm. For both alloy groups, retainers showed increase in vertical gap that implied poorer vertical fit after porcelain application. Mean values of inner fit change recorded for porcelain application firing were higher in magnitude than the values of metal-conditioning firing. In addition, no statistically significant differences were found among alloy types. Conclusions. A 3-dimensional distortion was observed both in Pd-Cu and Ni-Cr frameworks during porcelain firing cycle. The distortion seen after porcelain application firing was significantly greater than that seen after metal-conditioning firing. This result can be attributed to these factors, contamination of porcelain to the inner surface of metal coping and reduction in resilience of metal. (J Prosthet Dent 1998;80:654-60.)     

Fixed partial dentures opposing complete dentures

When fixed partial dentures are indicated in an arch opposing a complete denture, it is best to develop the occlusal surfaces of the fixed restorations at the same time that the opposing denture teeth are arranged in wax to permit greater flexibility and reduce the compromise in developing bilateral balanced occlusion. This article describes the development of bilaterally balanced occlusion between casting patterns for fixed partial dentures and a complete denture. The technique emulates the ease of arranging maxillary and mandibular denture teeth and can be used to develop fixed restorations with metal or porcelain occlusal surfaces. Porcelain occlusal surfaces are described because the use of porcelain is more technique sensitive.     

Fracture behavior of human mandibular incisors following endodontic treatment and porcelain veneer restoration

PURPOSE: Because of existing controversy, the present study investigated the individual and combined effects of endodontic treatment and porcelain veneer restoration on the fracture behavior of human mandibular incisors. MATERIALS AND METHODS: Forty extracted intact human mandibular incisors were assigned to four groups of ten with a similar range of labiolingual widths at the cementoenamel junctions. Group A consisted of intact teeth; group B consisted of endodontically treated teeth; group C teeth were restored with labial porcelain veneers; and those of group D were endodontically treated and had labial porcelain veneers. All teeth were subjected to a slow continuous loading test at 30 degrees to the long axis of the teeth and 1 mm below the incisal edge on the labial side. RESULTS: Fracture forces were 415 +/- 220 N, 370 +/- 89 N, 420 +/- 128 N, and 448 +/- 156 N for groups A, B, C, and D, respectively. Root fracture was the most common mode of failure. There were no statistically significant differences between the groups in terms of fracture forces and modes of failure. CONCLUSION: Human mandibular incisors with endodontic treatment and/or porcelain veneer restorations were able to withstand the same magnitude of oblique loading as intact teeth. Endodontic treatment and/or porcelain veneer restoration did not affect the mode of failure of mandibular incisors.     

The shear bond strength of composite brackets on porcelain teeth.

Recent advances in materials and techniques suggest that direct bonding of orthodontic attachments to surfaces other than enamel may now be possible. To test the effectiveness of bonding orthodontic attachments to porcelain teeth, composite brackets (Spirit MB) were bonded to 64 porcelain teeth by means of a self-cure non-mixed resin system (Unite). The 64 porcelain teeth were divided into groups of eight and after roughening with a green stone they were subjected to a combination of treatments. Some were etched, some primed with a silane coupling agent and some received both treatments before the brackets were bonded to them. Half of the teeth were then thermally-cycled 500 times between 4 and 60 degrees C before all the brackets were removed in a shear test. The shear data was analysed by one way analysis of variance and the Student-Newman-Keul test. The results showed that the highest bond strength existed in the group which had been both etched and primed but not thermocycled (P < 0.05). The factors that affected the bond strength, beginning with the most significant, were acid etching, primer application, and then thermocycling. A mechanical based composite bracket can offer good bond strength to porcelain teeth.     

Restoration of fixed partial dentures with fractured porcelain veneers using an overcasting

Fracture and loss of the porcelain veneer of a fixed partial denture is troublesome. Dentists have frequently used overcastings to avoid removal of the restoration. However, development of proximal resistance and retention form for the preparation creates a problem because reduction of the connector causes fracture. Nevertheless, a box-type occlusal cavity form in the central portion of the preparation will enhance the stability of the restoration without encroachment on the connectors. This design is more applicable to endodontically treated teeth.