Clinical application of ceramic restoration Ⅸ.Clinical application of ceramic restoration for dental implant

种植体瓷修复是目前临床常用的固定修复方法,分为金属烤瓷修复和全瓷修复.金属烤瓷修复技术将金属基底结构的强度和瓷的美学性能有机地结合起来,大大提高了修复体的抗折强度,因此,这一技术目前已广泛应用于临床种植体上部结构,其中金沉积烤瓷全冠因精密度高以及美学效果提高明显而在种植体瓷修复方面具有较大的优势,而美学效果更高的全瓷冠和全瓷基台的联合应用使种植体瓷修复更接近天然牙.     

Clinical application of ceramic restoration Ⅸ.Clinical application of ceramic restoration for dental implant

种植体瓷修复是目前临床常用的固定修复方法,分为金属烤瓷修复和全瓷修复.金属烤瓷修复技术将金属基底结构的强度和瓷的美学性能有机地结合起来,大大提高了修复体的抗折强度,因此,这一技术目前已广泛应用于临床种植体上部结构,其中金沉积烤瓷全冠因精密度高以及美学效果提高明显而在种植体瓷修复方面具有较大的优势,而美学效果更高的全瓷冠和全瓷基台的联合应用使种植体瓷修复更接近天然牙.     

Clinical application of ceramic restoration Ⅸ.Clinical application of ceramic restoration for dental implant

种植体瓷修复是目前临床常用的固定修复方法,分为金属烤瓷修复和全瓷修复.金属烤瓷修复技术将金属基底结构的强度和瓷的美学性能有机地结合起来,大大提高了修复体的抗折强度,因此,这一技术目前已广泛应用于临床种植体上部结构,其中金沉积烤瓷全冠因精密度高以及美学效果提高明显而在种植体瓷修复方面具有较大的优势,而美学效果更高的全瓷冠和全瓷基台的联合应用使种植体瓷修复更接近天然牙.     

Clinical application of ceramic restoration Ⅸ.Clinical application of ceramic restoration for dental implant

种植体瓷修复是目前临床常用的固定修复方法,分为金属烤瓷修复和全瓷修复.金属烤瓷修复技术将金属基底结构的强度和瓷的美学性能有机地结合起来,大大提高了修复体的抗折强度,因此,这一技术目前已广泛应用于临床种植体上部结构,其中金沉积烤瓷全冠因精密度高以及美学效果提高明显而在种植体瓷修复方面具有较大的优势,而美学效果更高的全瓷冠和全瓷基台的联合应用使种植体瓷修复更接近天然牙.     

Clinical application of ceramic restoration Ⅸ.Clinical application of ceramic restoration for dental implant

种植体瓷修复是目前临床常用的固定修复方法,分为金属烤瓷修复和全瓷修复.金属烤瓷修复技术将金属基底结构的强度和瓷的美学性能有机地结合起来,大大提高了修复体的抗折强度,因此,这一技术目前已广泛应用于临床种植体上部结构,其中金沉积烤瓷全冠因精密度高以及美学效果提高明显而在种植体瓷修复方面具有较大的优势,而美学效果更高的全瓷冠和全瓷基台的联合应用使种植体瓷修复更接近天然牙.     

Clinical application of ceramic restoration Ⅸ.Clinical application of ceramic restoration for dental implant

种植体瓷修复是目前临床常用的固定修复方法,分为金属烤瓷修复和全瓷修复.金属烤瓷修复技术将金属基底结构的强度和瓷的美学性能有机地结合起来,大大提高了修复体的抗折强度,因此,这一技术目前已广泛应用于临床种植体上部结构,其中金沉积烤瓷全冠因精密度高以及美学效果提高明显而在种植体瓷修复方面具有较大的优势,而美学效果更高的全瓷冠和全瓷基台的联合应用使种植体瓷修复更接近天然牙.     

Clinical application of ceramic restoration Ⅸ.Clinical application of ceramic restoration for dental implant

种植体瓷修复是目前临床常用的固定修复方法,分为金属烤瓷修复和全瓷修复.金属烤瓷修复技术将金属基底结构的强度和瓷的美学性能有机地结合起来,大大提高了修复体的抗折强度,因此,这一技术目前已广泛应用于临床种植体上部结构,其中金沉积烤瓷全冠因精密度高以及美学效果提高明显而在种植体瓷修复方面具有较大的优势,而美学效果更高的全瓷冠和全瓷基台的联合应用使种植体瓷修复更接近天然牙.     

Monolithic and bi-layer CAD/CAM lithium–disilicate versus metal–ceramic fixed dental prostheses: Comparison of fracture loads and failure modes after fatigue

Objectives

The authors analyzed the effect of fatigue on the survival rate and fracture load of monolithic and bi-layer CAD/CAM lithium–disilicate posterior three-unit fixed dental prostheses (FDPs) in comparison to the metal–ceramic gold standard.

Materials and methods

The authors divided 96 human premolars and molars into three equal groups. Lithium–disilicate ceramic (IPS-e.max-CAD) was milled with the CEREC-3-system in full-anatomic FDP dimensions (monolithic: M-LiCAD) or as framework (Bi-layer: BL-LiCAD) with subsequent hand-layer veneering. Metal–ceramic FDPs (MC) served as control. Single-load-to-failure tests were performed before and after mouth-motion fatigue.

Results

No fracture failures occurred during fatigue. Median fracture loads in [N], before and after fatigue were, respectively, as follows: M-LiCAD, 1,298/1,900; BL-LiCAD, 817/699; MC, 1,966/1,818. M-LiCAD and MC FPDs revealed comparable fracture loads and were both significantly higher than BL-LiCAD. M-LiCAD and BL-LiCAD both failed from core/veneer bulk fracture within the connector area. MC failures were limited to ceramic veneer fractures exposing the metal core. Fatigue had no significant effect on any group.

Conclusions

Posterior monolithic CAD/CAM fabricated lithium–disilicate FPDs were shown to be fracture resistant with failure load results comparable to the metal–ceramic gold standard. Clinical investigations are needed to confirm these promising laboratory results.

Clinical relevance

Monolithic CAD/CAM fabricated lithium–disilicate FDPs appeared to be a reliable treatment alternative for the posterior load-bearing area, whereas FDPs in bi-layer configuration were susceptible to low load fracture failure.     

In vitro comparison of the load-bearing capacity of ceramic and metal-ceramic resin-bonded fixed dental prostheses in the posterior region

Statement of problem

The clinical use of ceramic resin-bonded fixed dental prostheses (RBFDPs) in the posterior region is desirable for esthetic and biological reasons but has been associated with many technical problems, including fractures or chipping of the veneer. Although these problems may be overcome by using monolithic zirconia, information is lacking about the load-bearing capacity of resin-bonded monolithic zirconia restorations for replacing a molar.

Effect of porous glass–ceramic fillers on mechanical properties of light-cured dental resin composites

ObjectivesThe aim of this work was to study the effect of porous particles on the mechanical properties of dental resin composites.MethodsTwo kinds of glass–ceramic powders with different calcium–mica to fluorapatite ratio were used as inorganic fillers for light-cured dental resin composites. The glass–ceramic particles were etched to introduce porous structures. The microstructures of particles and the fractography of dental composites were observed using SEM/EDS. The crystalline phases in the fillers were determined by XRD. The specific surface areas (SBET) of porous fillers were tested to show the degree of porosity. 6 samples were prepared for each bending strength test, which was conducted in a Mechanical Testing System.ResultsThe results show that the bending strength does not vary monotonically with the porosity of the particles. For the glass–ceramics with a high nominal calcium–mica to fluorapatite ratio, the dental resin filled with porous particles has a higher strength than that filled with dense particles; however, for the glass–ceramics with a low nominal calcium–mica to fluorapatite ratio, the dental resin filled with porous particles has a lower strength.SignificanceThe study indicates that the porosity itself is not a decisive factor for strengthening of dental resin composites. The composition of the glass–ceramic particles and the porous structure are also essential factors influencing the mechanical strength. The investigation on the effect of porous glass–ceramic fillers will provide more understanding on the mechanical properties of dental resin composites and will help with the design of new dental restorative materials.     

Finite element analysis to compare stress distribution of connector of lithia disilicate-reinforced glass–ceramic and zirconia-based fixed partial denture

This study used finite element method to analyze the stress distribution in connector of ceramic-based bilayer structures, in simulation of dental crown-like structures with a functional but weak veneer layer bonded onto a strong core layer. The purpose of this study was to evaluate the stress distribution at veneer/core interface of 2 different core materials [Yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) and lithia disilicate-reinforced glass–ceramic] using three-dimensional finite element analysis. Within the limitations of this study, finite element analysis showed that stress concentrations were located at the veneer/core interface of the connector in Y-TZP core models. The general observation was that compared with Y-TZP, lithia disilicate-reinforced glass–ceramic showed a relatively stable stress value and had a minor effect on the stress concentration susceptibility.     

Total reconstruction of the temporomandibular joint. Up to 8 years of follow-up of patients treated with Biomet® total joint prostheses

12 patients underwent temporomandibular joint (TMJ) reconstruction with Biomet total joint prostheses. Indications for TMJ reconstruction included ankylosis, rheumatoid arthritis, degenerative joint disease and condylar resorption. Five patients had unilateral procedures, seven had bilateral. The follow-up ranged between 2 and 8 years. Amongst the ankylotic patients the mean jaw-opening capacity increased from 3.8 mm preoperatively to 30.2 mm 1 year after surgery, and in most of those patients the opening capacity remained stable over the years. The other patients maintained a mean opening capacity of more than 35 mm. Joint related pain and interference with eating were eliminated after TMJ reconstruction. There were no permanent facial nerve disturbance, no postoperative infections and no device related complications. The outcome supports prosthetic TMJ reconstruction as a useful treatment modality in patients with advanced TMJ disease.     

Fracture behaviour of implant–implant- and implant–tooth-supported all-ceramic fixed dental prostheses utilising zirconium dioxide implant abutments

This in vitro study investigated the fracture behaviour of implant–implant-supported and implant–tooth-supported all-ceramic fixed dental prostheses (FDP) using zirconium dioxide implant abutments (FRIADENT® CERCON® abutments, DENTSPLY Friadent). Six different test groups (n?=?8) were prepared. Groups 1, 2, 4, and 5 represented an implant–implant-supported FDP condition, whereas groups 3 and 6 simulated an implant–tooth-supported FDP condition. The second right premolar of the mandible was replaced with a pontic tooth. In groups 2 and 5, implant abutments were individualised by circumferential preparation. XiVe® S plus screw implants (DENTSPLY Friadent) that were 4.5 mm (first molar) and 3.8 mm (first premolar) in diameter and 11 mm in length and metal tooth analogues with simulated periodontal mobility, representing the first right premolar, were mounted in a polymethyl methacrylate block. The FDPs were cemented with KetacCem (3 M Espe GmbH, Germany). Groups 4, 5, and 6 were thermomechanically loaded (thermal and mechanical cycling (TCML)?=?1.2?×?10⁶; 10,000?×?5°/55°) and subjected to static loading until failure. Statistical analysis of data obtained for the force at fracture was performed using non-parametric tests. All samples tested survived TCML. In the implant–implant-supported groups, circumferential abutment preparation resulted in a tendency to lower fracture forces compared to groups with unprepared abutments (group 1, 472.75?±?24.71 N; group 2, 423.75?±?48.48 N; group 4, 647.13?±?39.10 N; group 5, 555.86?±?30.34 N). The implant–tooth-supported restorations exhibited higher fracture loads (group 3, 736.25?±?82.23 N; group 6, 720.75?±?48.99 N) than the implant–implant-supported restorations which did not possess circumferentially individualised abutments. Statistically significant differences were found when comparing the non-artificially aged groups. Implant–tooth-supported FDP restorations did exhibit an increased fracture load compared to implant–implant-supported FDP restorations.     

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.     

Microstructure analysis of dental castings used in fixed dental prostheses—a simple method for quality control

The aim of this study was to evaluate the microstructural quality of noble alloy castings from commercial dental laboratories using the wiping–etching method as a simple method for quality control. In total, 240 castings from two noble alloys (AuAgCuPt and AuPtZn) were taken from a day's production of five different dental laboratories. The casting quality was evaluated by determining the grain size and by assessing the number and size of shrinkage cavities after acidic etching of the alloy surfaces. The AuAgCuPt alloy castings showed an acceptable quality in the microstructural analysis. The results of AuPtZn castings, however, were not satisfactory because 50.8% of the samples showed a remarkably poorer quality compared to the specifications made by the manufacturer. The proportion of the employed reclaimed alloy had no influence on the casting quality when AuAgCuPt alloy was used, but was influential when casting restorations with AuPtZn alloy. When determining the quantity and size of shrinkage cavities, none of the evaluated castings was of such a poor quality that a replacement of the castings had to be considered. The differences in grain size and quantity of shrinkage cavities were reflecting the individual laboratory process rather than the admixture of new/reclaimed alloy. The presented analysis can be used as a simple method for quality control of dental castings.     

Systematic review of short- (5–10 years) and long-term (10 years or more) survival and success of full-arch fixed dental hybrid prostheses and supporting implants

Objectives

The aim of this systematic review was to investigate the short-term (5–10 year mean follow-up) and long-term (10 year or more) survival and success of fixed full arch dental hybrid prosthesis and supporting dental implants.

Methods

Studies reporting interventions with full-arch fixed dental hybrid prostheses were identified by searching PubMed/Medline (NCBI), Web of Science (Thomson Reuters), the Cochrane Register of Controlled Clinical Trials (EBSCO), and Dentistry and Oral Sciences Source (DOSS; EBSCO) from the earliest available dates through July 17, 2013. Through a series of review process by two examiners, potentially qualifying studies were identified and assessed with respect to the inclusion criteria.

Results

A total of 18 studies were included for the quality assessment and the systematic review. Within the limitation of available studies, high short-term survival rates of full arch fixed dental hybrid prostheses (93.3–100%) and supporting implants (87.89–100%) were found. However, the availability of studies investigating long-term outcomes seemed scarce. Furthermore, the included studies were subjected to potential sources of bias (i.e. publication, reporting, attrition bias).

Conclusions

Despite seemingly high short-term survival, long-term survival of implant supported full arch fixed dental hybrid prosthesis could not be determined due to limited availability of true long-term studies. Although it may be a valuable option for a patient with a completely edentulous ridge(s), the strategic removal of teeth with satisfactory prognosis for the sake of delivering an implant supported full-arch dental hybrid prosthesis should be avoided.     

Clinical performance of zirconia–ceramic cantilever fixed partial dentures—Longitudinal nine-year results from a prospective,randomized, controlled pilot study

PurposeThe aim of this study was to prospectively compare the clinical performance of veneered zirconia cantilever fixed partial dentures (Z-CFPDs) and metal–ceramic CFPDs (MC-CFPDs) over 9 years of follow-up in terms of survival.MethodsTwenty-one participants were assigned by simple randomization to receive either 1 Z-CFPD (n = 11) or 1 MC-CFPD (n = 10). CFPDs were retained by 2 full crowns and replaced a missing premolar or a central or lateral incisor. Modified USPHS (United States Public Health Service) criteria were used to classify material chipping, retention, marginal integrity, secondary caries, and color of the restorations. The satisfaction of the study participants with the esthetics of their restorations was surveyed; pocket probing depths (PPD), plaque index (PI), and gingival index (GI) were also measured. Study groups were compared by use of U tests (continuous variables), or by use of Fisher exact probability tests (categorical variables) with α = 0.05.ResultsSixteen participants (n = 8 with a Z-CFPD and n = 8 with an MC-CFPD) attended the 9-year follow-up examination (response rate: 76.2%). Over the 9-year study period, survival of 50% for Z-CFPDs and 75% for MC-CFPDs was recorded (p = 0.608). No framework fractures occurred, and no statistically significant differences were observed between the groups regarding changes in PPD, PI, GI, or participant satisfaction (p > 0.05). USPHS criteria revealed statistically significantly poorer marginal quality for Z-CFPDs than for MC-CFPDs (p = 0.009).ConclusionWithin the limitations of this study, Z and MC-CFPDs demonstrated no statistically significant difference in terms of survival.     

Risk of chipping or facings failure of metal ceramic fixed partial prostheses—a retrospective data record analysis

This retrospective study investigated the frequency and time history of chipping or facings failure of three-unit and four-unit tooth-supported metal ceramic (MC) fixed partial prostheses (FPDs). Six hundred fifty-four MC FPDs were inserted according to a standardized treatment protocol at the Department of Prosthodontics of the Regensburg University Medical Center between 1984 and 2009. Frequency and time history of chipping or facings failure as well as possible risk factors were evaluated on the basis of historical clinical data. We estimated the survival times of FPDs by means of the Kaplan–Meier analysis. The 5-year survival rate (time to renewal of a FPD) of all MC FPDs was 94%; the 10-year survival rate was 87%. Twenty-eight (4.3%) MC FPDs showed chipping; the 5-year free-of-event rate of chipping was 95%, the 10-year rate was 94%. Possible risk factors had no statistically significant influence on chipping or facings failure. The annual hazard rate of MC chipping in the first year was 0.03, i.e., 3 out of 100 person-years of exposure showed chipping. The annual hazard rates for the next 6 years dropped to 0.009, 0.003, 0.007, 0.004, 0.005, and 0.007. Thus, about 3–9 out of 1,000 person-years of exposure showed chipping. Patients with MC FPD may expect a long survival rate of their restoration. During the first year, the risk of chipping may be higher than during the following years. Despite the long period of experience with MC FPDs, chipping of the facing will still occur.