Strength of bond with Comspan Opaque to three silicoated alloys and titanium

Abstract – In Sweden high-gold alloys or cobalt-chromium alloys are used for resin-bonded prostheses. The bond strength between a resin cement and different sandblasted or silicoated metals were measured before and after thermocycling; in connection with this some rapid thermocycling methods were studied. The effect of different storage times and different protection coatings on bond strength were tested. Finally, the influence of rubbing and contamination with saliva on bond strength were investigated. Silicoating increased the bond strength significantly. The highest bond strengths were these of silicoated Wirobond and titanium, unsusceptible to thermal stress; the bond strengths of the sandblasted metals were the weakest, and sensitive to thermocycling as well. The influence on bond strength for silicoated gold alloys, protected with an unpolymerized composite resin coating, stored in sealed plastic bags up lo 7 days, was negligible. Rubbing and contamination with saliva did not influence bond strength. Preferably, silicoated Wirobond and titanium should be used for resin-bonded prostheses, but gold alloys may still be adequate for clinical use. The experimental method described for storing, sealing, and cleaning the silicoated metal surfaces in this article can be recommended for laboratory and clinical use.     

Bond strengths of resin-bonded metal castings

Composite resin-retained appliances are susceptible to failure at the resin-metal interface. The objective of this study was to evaluate bond strengths of perforated and electrolytically etched framework designs by subjecting them to tensile and shear loading. Shear bond strengths were always higher than tensile bond strengths. Etched castings were consistently stronger than perforated designs. Castings that were both perforated and etched were stronger in tension than all other retentive designs.     

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金属翼板粘接桥是以金属翼板为固位体,金属熔附烤瓷为桥体,使用树脂粘接剂粘接在基牙上的一种修复方法。其优点是牙齿磨除量小,避免牙髓损伤,预备时不需麻醉,制取印模不需要排龈等。本文主要介绍金属翼板粘接桥的设计、牙体预备、金属翼板的处理方法、粘接剂等相关问题以及粘接桥的一些特殊使用方法。     

A comparison of 3 alloy surface treatments for resin-bonded prostheses

PURPOSE: The most frequent cause of clinical failure of resin-bonded fixed partial dentures is a debonding at the metal-cement interface. The purpose of this in vitro study was to compare the tensile bond strengths of 3 different alloy-surface treatments when cemented to human enamel with a resin cement. MATERIALS AND METHODS: Cylinders of a nickel-chromium-beryllium (Ni-Cr-Be) and a gold-palladium (Au-Pd) alloy were fabricated and assigned to different surface treatment groups as follows: Group 1: Ni-Cr-Be, chemically etched; Group 2: Au-Pd, airborne particle-abraded and tin-plated; and Group 3: Au-Pd, airborne particle-abraded and treated with the Alloy Primer (Kuraray Co, LTD, Osaka, Japan). The cylinders were bonded to the enamel surfaces of extracted, human third molars and stored in normal saline at 37 degrees C for 48 hours. The tensile bond strength of 21 specimens from each group was measured on a Universal Testing Machine (Instron, Canton, MA). Three failed specimens of each group were evaluated using scanning electron microscopy and energy dispersive spectroscopy. RESULTS: Statistically significant differences (p <.05) were found between all 3 treatment groups. The mean tensile bond strengths (+/- the standard error of mean) recorded as follows: Group 1: 10.6 MPa (+/-1.3), Group 2: 0.9 MPa (+/-0.2), and Group 3: 13.4 MPa (+/-1.0). Specimens from groups 1 and 3 revealed a trend towards mixture of cohesive, within the resin cement, and adhesive failures at the metal-cement interface. Group 2 specimens exhibited primarily adhesive failures at the metal-cement interface. CONCLUSIONS: The tensile bond strength of Au-Pd alloy specimens was significantly increased with the Alloy Primer.     

针道辅助固位金属翼板粘接桥的临床初步观察

目的 观察针道辅助固位金属翼板粘接桥修复的临床短期效果.方法 对65例牙列缺损患者进行针道辅助固位金属翼板粘接桥修复,随访修复体固位和基牙健康状况.结果 65例患者共制作74件修复体,随访6～34个月,平均12.4个月.3件修复体松动、脱落,脱粘率为4%.基牙牙本质敏感9例(14%).结论 针道辅助固位可显著提高金属翼板粘接桥的短期成功率,获得良好的临床效果.其长期成功率尚需进一步观察.     

Long-term clinical evaluation of 211 two-unit cantilevered resin-bonded fixed partial dentures

Objectives

This retrospective study aims to evaluate the long term clinical performance of two-unit cantilevered resin-bonded fixed partial dentures (RBFPDs) relating to their retention, success and survival rate.

Materials and methods

Prostheses that were placed at least four years previously were clinically reviewed to evaluate retention, success and survival rate. Additional information was also collected, including patient's gender, age and satisfaction on their prosthesis, operator's experience, prosthesis service life, root canal therapy if performed, abutment mobility, bone support, the presence of shim-stock contacts on the abutment or pontic in intercuspal position, and the presence of proximal axial contacts adjacent to the prosthesis. The date of any debonding with subsequent treatment was also recorded.

Results

A total of 211 two-unit RBFPDs were placed in 153 patients, with a mean service life of 113.2 ± 33.5 months. Twenty-eight prostheses debonded, resulting in a retention rate of 86.7 percent, and another five teeth were extracted with the prostheses, resulting in a success rate of 84.4 percent. 90.0 percent prostheses were functioning (survival rate) by means of rebonding at the time of review. The location of the replaced tooth had a significant effect on the retention of RBFPDs with posterior RBFPDs lower than anterior (p = 0.020). Kaplan–Meier analysis revealed 5-, 10- and 15-year cumulative probability of surviving was 0.97, 0.91 and 0.84, respectively.

Conclusions

211 two-unit RBFPDs were observed to have a success, retention and survival rate of 84.4, 86.7 and 90.0 percent, respectively, with a mean service life of 9.4 years.

Clinical Significance

Based on the clinical results, two-unit RBFPD are shown to be a durable prosthesis over the long term with high patient satisfaction. The posterior prostheses, particularly in the lower arch appeared to have a higher failure rate, and improved design features should be considered.     

Shortcomings of prosthodontic rehabilitation of patients living in long‐term care facilities

Removable dentures are a non‐invasive, cost‐effective prosthodontic solution for the reduced dentition. Their intended purpose is the rehabilitation of harmonious oral function and aesthetics on a long‐term basis. The prevalence of removable dentures among patients of advanced age is high and the quality of the dentures is often poor. The aim of this study was to find the most important shortcomings of removable dentures and address the main targets for improving the quality of prosthodontic rehabilitation. The records from dental check‐ups in Austrian residential homes were analysed retrospectively. Dental anamnesis questionnaires and data from the clinical examinations of 105 denture wearers were analysed. The functional condition and retention of 192 dentures had been assessed, as well as the impact of the dentures on the intra‐oral tissues. Insufficient denture retention was very common, particularly in the lower jaw (56·0%). Problems with the masticatory function were reported by 26.7% of the denture wearers, 11·4% were dissatisfied with the denture aesthetics, and 4·8% had difficulties with phonetics. Traumatic ulcers were found in 18·1%. Cracks, broken pieces (6·3%) or missing denture teeth (2·1%) were rare. It may be assumed that the findings of the present study also apply to a great percentage of community‐dwelling seniors. The most important issues in prosthodontic rehabilitation with removable dentures are denture retention and masticatory function. Regular dental check‐ups, denture adjustment and, when necessary, relining can maintain the primary denture quality and prevent damages of the oral tissues caused by ill‐fitting dentures.     

A systematic review and meta‐analysis of 3‐unit fixed dental prostheses: Are the results of 2 abutment implants comparable to the results of 2 abutment teeth?

The purpose of the systematic review and meta‐analysis was to compare the performance of 3‐unit bridges on teeth with 3‐unit bridges on implants, evaluating survival of the bridges, survival of the teeth or implants, condition of the hard and soft tissues surrounding the supports, complications and patient‐reported outcome measures (PROM) after a mean observation period of at least 1 year. A literature search was conducted using a combination of the search terms: fixed partial denture and fixed dental prostheses (FDPs). An electronic search for data published until January 2017 was undertaken using the MEDLINE, EMBASE and Cochrane Library databases. Eligibility criteria included clinical human studies, either randomised or not, interventional or observational, which evaluated the results of 3‐unit FDPs on either 2 implants or 2 abutment teeth. The search identified 1686 unique references. After applying eligibility criteria, 66 articles were included in the analysis. A total of 1973 3‐unit FDPs were supported by teeth, and 765 were implant‐supported. No significant differences were found either in the survival of the supporting abutments (P = .52; 99% vs 98.7% survival per year) or in the survival of the prostheses (P = .34; 96.4% vs 97.4% survival per year). Both treatments show an almost equally low complication rate, but there is a low level of reporting of hard and soft tissue conditions and PROM. It is concluded that implant‐supported 3‐unit FDPs seem to be a reliable treatment with survival rates not significantly different from the results of teeth‐supported 3‐unit FDPs.     

粘接固定桥的固位及研究进展

粘接桥因其微创的优点重新受到推崇,而修复体材料、粘接面的处理技术和粘接剂系统等的发展也给予其新的应用发展机会。本文对粘接桥的固位研究和发展进行综述,以期更新口腔修复医生对粘接桥的认识,使这种微创而有效的修复方法受到应有的重视。     

A retrospective clinical evaluation of two-unit cantilevered resin-bonded fixed partial dentures

BACKGROUND: The authors conducted a study to examine the clinical performance of two-unit cantilevered resin-bonded fixed partial dentures (RBFPDs) that were inserted at The Prince Philip Dental Hospital, University of Hong Kong. METHODS: The authors recalled patients who had received two-unit cantilevered RBFPDs at least 24 months before the recall examination. The authors recorded the following data: patient's sex and age, operator's experience, prosthesis cementation date, endodontic treatment if performed, bone support, tooth mobility, the presence of shim-stock contacts on the abutment or pontic in intercuspal position, and the presence of aproximal axial contacts adjacent to the prosthesis. They also recorded the date of any debonding with subsequent treatment. They asked the patients qualitative questions about their prostheses. RESULTS: A total of 269 prostheses were placed in 214 patients and had a mean service life of 51.7 months +/- 19.5 months standard deviation, with a range of 13.2 to 141.6 months. Of 14 failed prostheses, 12 debonded, resulting in a success rate of 94.8 percent and clinical retention rate of 95.5 percent. No discernable rotation or drifting of the abutments was apparent in any of the prostheses. Overall patient satisfaction with RBFPDs was good, with an average assessment score of 8.5. CONCLUSIONS: The authors observed a 95.5 percent clinical retention rate of 269 two-unit RBFPDs, with no apparent drifting of the abutments. Longer-term follow-up studies are required. CLINICAL IMPLICATIONS: Two-unit RBFPDs are conservative and clinically retentive prostheses in the short to medium term.     

老年人固定修复中临时冠制作方法比较

目的:为了缩短老年患者就诊时间及减少复诊次数,设计并比较应用3种复合树脂制作临时冠方法的时间长短及临时修复体对龈缘的影响,寻找适合老年患者的临时冠制作方法.方法:72例需作固定修复的老年患者随机分为三组,一组采用口内复制法制作临时冠;另一组采用基牙制备后取印模,口外模型制作临时冠;再一组采用口内直接法制作临时冠.结果:三组制作的临时冠戴后2周检测龈缘密合度及临时冠对龈缘的影响,各组之间比较差异无显著性.三组制作临时冠从总操作时间上比较,口内复制法费时较少;但从口内操作时间上比较,口外模型法用时最少,适合于老年患者固定修复的临时冠制作.结论:口腔外模型法能减少口内操作时间,适合于老年患者治疗.     

Mastication and jaw motion of partially edentulous patients are affected by different implant‐based prostheses

The main goal of prosthetic treatment is to restore masticatory function. However, insufficient evidence supports the recommendation of one specific prosthetic intervention for partially edentulous patients. Function after the use of three different prostheses by the same partially edentulous subject. Mastication was assessed in 12 subjects (mean age 62·6 ± 7·8 years) after they had used removable partial dentures (RPDs), implant‐supported partial dentures (IRPDs) and implant‐fixed partial dentures (IFPDs). Masticatory ability (MA) was estimated by visual analogue scale questionnaire, while the mandibular chewing motion was evaluated by kinesiographic device, representing an objective measurement of masticatory function. Data were analysed by repeated‐measures anova followed by Tukey–Kramer (P < 0·05). MA improved after IRPD and IFPD use (P < 0·05). Opening, closing and total cycle time duration were reduced after both IRPD and IFPD use (P < 0·05), irrespectively the implant prosthesis type. IFPDs and IRPDs restore the masticatory function of partially edentulous patients better than RPDs.     

抛光方法对钴铬合金铸造全口义齿密合度的影响

［摘要］ 目的 探讨5种抛光方法对钴铬合金铸造全口义齿密合度的影响。方法 铸造上颌钴铬合金全口基托板30个,随机分为6组,1组作为对照,5组分别用光整、电解、打磨、打磨后电解、打磨后光整等5种方法抛光。在相当于上颌第二磨牙远中部位切断义齿基托与标准模型,数字万能工具显微镜分别测量上颌全口义齿基托组织面与标准模型齿槽嵴顶点、腭中缝点及其两者的中点之间共5个部位的间隙,并用电子数显卡尺测量5个点的基托板厚度。结果 6组铸造基托板的厚度,除了光整组试样的厚度与抛光前试样厚度无统计学差别外(P>0.05),其余各组均与抛光前试样厚度有统计学差别(P<0.01)。抛光前、后5点间隙值没有组间统计学差别(P>0.05)。结论 5种抛光方法对上颌铸造全口基托的密合度无影响。     

Oral rehabilitation considerations for partially edentulous periodontal patients

Traditional tooth-supported and implant-supported fixed/removable restorations are currently used to replace teeth lost due to periodontal disease. This article reviews the existing literature for oral rehabilitation of partially edentulous periodontal patients with various designs of removable dental prosthesis (RDP), fixed dental prosthesis (FDP) and implant-supported single crown (SC), by addressing their (a) general features, (b) survival and complication rates, along with considerations for treatment planning in periodontal patients, and (c) preference by patients. To answer these issues, relevant articles were searched and critically analyzed, and their data were extracted. Data reviewed indicated that despite many advantages, implant-supported restorations have higher complication rates than tooth-supported restorations. Systematic reviews on conventional RDPs are lacking, but existing literature reviews provide limited evidence suggesting the use of RDPs with design modifications along with strict periodontal care in periodontal patients. Numerous systematic reviews on conventional FDPs and implant-supported restorations provide a moderate level of evidence favoring their survival in periodontal patients; however, for long-term success of these restorations, the patient's periodontal condition needs to be stabilized. In terms of patient preference, no restoration is superior, as they all are governed by their cost, advantages, and disadvantages. Thus, in the wake of existing weak evidence for prosthodontic rehabilitation of periodontal patients by these restorations (especially, conventional RDPs and for FDPs and SCs in implant-supported restorations), longitudinal studies with standardized treatment protocol and methodology are needed to evaluate and compare tooth-supported and implant-supported restorations in periodontal patients with regard to survival rates, cost, maintenance, and patient-centered outcomes.