Article

A 5-year retrospective study of survival of zirconia single crowns fitted in a private clinical setting

February 2012
Journal of Dentistry 40(6):527-30

DOI:10.1016/j.jdent.2012.02.011

Source
PubMed

Authors:

University of Gothenburg

The aim of this report was to evaluate the 5-year clinical performance and survival of zirconia (NobelProcera™) single crowns. All patients treated with porcelain-veneered zirconia single crowns in a private practice during the period October 2004 to November 2005 were included. The records were scrutinized for clinical data. Information was available for 162 patients and 205 crowns. Most crowns (78%) were placed on premolars and molars. Out of the 143 crowns that were followed for 5 years, 126 (88%) did not have any complications. Of those with complications, the most common were: extraction of abutment tooth (7; 3%), loss of retention (15; 7%), need of endodontic treatment (9; 4%) and porcelain veneer fracture (6; 3%). No zirconia cores fractured. In total 19 restorations (9%) were recorded as failures: abutment tooth extraction (7), remake of crown due to lost retention (6), veneer fracture (4), persistent pain (1) and caries (1). The 5-year cumulative survival rate (CSR) was 88.8%. According to the present 5-year results zirconia crowns (NobelProcera™) are a promising prosthodontic alternative also in the premolar and molar regions. Out of the 143 crowns followed for 5 years, 126 (88%) did not have any complications. However, 9% of the restorations were judged as failures. Further studies are necessary to evaluate the long-term success.

Clinical outcomes of single crown and 3-unit bi-layered zirconia-based fixed dental prostheses: An upto 6- year retrospective clinical study

Article

Oct 2022
J DENT

Objectives: The aim of this retrospective clinical study was to evaluate the survival and the occurrence of technical and biological complications in bi-layered zirconia-based (Zi) single crown and 3-unit fixed dental prostheses (FDPs). Also, the study aimed to analyze the effects of tooth vitality (vital versus non-vital), abutment location (anterior versus posterior), and luting cement (self-adhesive resin versus resin-reinforced glass ionomer) on clinical outcomes. Methods: A total of 147 prostheses (in 94 patients) placed by undergraduate dental students in a university dental center during the period 2015-2021 were examined clinically using modified United States Public Health Service (USPHS) and California Dental Association (CDA) criteria. The mean duration of follow-up was 37 months (range, 6 - 63 months) for the single crowns (n = 77) and 25 months (range, 6 - 68 months) for the 3-unit FDPs (n = 70). Data were descriptively analyzed to determine the types and rates of complications based on USPHS and CDA criteria. The Kaplan-Meier survival estimation method was used to determine the cumulative survival and success rates of the prostheses (α=.05). Differences in clinical outcomes (survival or failure) according to tooth vitality, luting cement, and location were statistically analyzed using cross-tabulations and Х2 test (α=.05). Results: The Kaplan-Meier cumulative survival rate was estimated as 96% for the Zi 3-unit FDPs after 5.5 years, and 90% for the Zi single crowns after 4.8 years. The 5-year estimated success rate was 68% for both 3-unit FDPs and single crowns. Seven (9.1%) single crowns and 2 (2.9%) 3-unit FDPs were recorded as failures, with occlusal roughness being the most commonly-observed complication (crowns: 4 [5.6%]; 3-unit FDPs: 8 [11.4%]). In terms of clinical outcomes, statistically significant differences were found between all included vital and non-vital teeth (p=.006), and cement types (p=.028). Taking single crowns alone, significant differences in clinical outcomes according to tooth vitality were noted (p=.036), but not for PFDPs. The location of the prostheses did not produce any significant differences in the clinical outcomes, for both prostheses types independently or combined (p>.05). Conclusions: The estimated cumulative survival rates in this study for single crowns and 3-unit Zi FDPs concurred with the ranges reported in systematic reviews. Zi-based prostheses on vital teeth produced better clinical outcomes than those placed on non-vital teeth, and type of luting cement influenced the final clinical outcome. Clinical significance: Zi crowns and 3-unit PFDPs fabricated using the specific CAD-CAM system used in the controlled environment of this study showed good clinical performance with minimal veneer porcelain chipping. Root canal treated teeth seem to be at higher risk for failure of Zi prostheses compared with vital teeth.

Comparison of the clinical outcomes of resin-modified glass ionomer and self-adhesive resin cementations for full-coverage zirconia restorations

Article

Aug 2023
J DENT

Objectives: Both resin-modified glass ionomer cement (RMGIC) and self-adhesive resin cement (SAC) may be suitable for cementation of full-coverage zirconia restorations. This retrospective study aimed to investigate the clinical outcomes of zirconia-based restorations cemented with RMGIC and compare them with those cemented with SAC. Methods: Cases of full-coverage zirconia-based restorations cemented with either RMGIC or SAC between March 2016 and February 2019 were evaluated in this study. The clinical outcomes of the restorations were analyzed according to the type of cement used. In addition, cumulative success and survival rates were evaluated according to the cement and abutment types. Non-inferiority, Kaplan-Meier, and Cox hazard tests were conducted (α=.05). Results: A total of 288 full-coverage zirconia-based restorations (natural teeth, 157; implant restorations, 131) were analyzed. Loss of retention occurred in only one case; a single-unit implant crown cemented with RMGIC, which decemented 4.25 years post-restoration. RMGIC was non-inferior to SAC in terms of loss of retention (<5%). For single-unit natural tooth restorations, the four-year success rates in the RMGIC and SAC groups were 100% and 95.65%, respectively (p=.122). For single-unit implant restorations, the four-year success rates in the RMGIC and SAC groups were 95.66% and 100%, respectively (p=.365). The hazard ratios of all the predictor variables, including cement type, were not significant (p>.05). Conclusions: Cementation of full-coverage zirconia restorations of both natural teeth and implants using RMGIC and SAC yields satisfactory clinical outcomes. Furthermore, RMGIC is non-inferior to SAC in terms of cementation success. Clinical significance: Cementation with RMGIC or SAC for full-coverage zirconia restorations has favorable clinical outcomes in both natural teeth and implants. Both RMGIC and SAC have advantages in the cementation of full-coverage zirconia restorations to abutments with favorable geometries.

Factors that Influence the Clinical Longevity of Ceramic Unit Restoration: A Scoping Review

Article

Full-text available

Mar 2022

Statement of Problem: Ceramic restorations can be essential in dental rehabilitation aesthetic and functional, but its longevity and treatment plan need to be good settled down. Different material options, manufacturing techniques and protocols are available. It is important to map the literature to know the state of the art about of clinical failures related to these fixed prostheses. Purpose: Evaluate the rate of survival of single restorations (crowns and ceramic veneers) as well as identify the types of clinical complications reported. Material and methods: A scoping review was conducted from the MEDLINE/Pubmed, Embase, Scopus, Web of Science and Cochrane Library. A search of all published literature until June 2021 was based on the following keywords: ('dental crown' OR 'ceramic veneer' OR 'porcelain veneer' OR 'dental veneer' OR 'dental porcelain') AND ('survival rate' OR 'ceramic restoration failure' OR 'prosthesis complication' OR complication). Results: The most reported biological complications were need for treatment endodontic and detachment. The complications and technical failures involved, mainly, fractures and cracks in ceramics. There were also cases of pigmentation marginal. Conclusion: The survival rate of single ceramic restorations is high. The main factors influencing restoration failures are bruxism, operator inexperience and inadequate cementation.

Glass Ionomer Versus Self-adhesive Cement and the Clinical Performance of Zirconia Coping/Press-on Porcelain Crowns

Article

Sep 2021

Objective: This split-mouth clinical study investigated the effect of luting cement on the performance of veneered yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) zirconia crowns. Methods and Materials: A total of 60 crowns prepared with Y-TZP coping and press-on porcelain were made with a split-mouth design in 30 participants. The crowns were cemented either with glass ionomer cement (GIC) (Meron, Voco) or with self-adhesive resin cement (Bifix-SE, Voco). The restorations were assessed immediately after treatment and after 6, 12, 24, 36, and 48 months using the modified United States Public Health Service criteria. The parameters analyzed were retention, color stability, marginal discoloration, marginal adaptation, surface roughness, anatomic form, and secondary caries. The differences between the groups were analyzed by the Fisher exact test in each period of evaluation. The survival rate was analyzed with the Kaplan–Meier and log-rank test (α=0.05). Results: After 48 months, 20 participants attended the recall. During the period of evaluation, 1 crown cemented with glass ionomer cement and 1 crown cemented with resin cement lost retention. Color match, marginal discoloration and adaptation, surface roughness, and anatomic form did not change in any of the periods evaluated, and no secondary caries was observed. No significant differences were found between the 2 luting cements for any of the clinical parameters analyzed, nor for the survival rates during the study. Conclusions: The type of cement did not influence the performance of the crowns after 48 months of clinical use. Both cements resulted in adequate retention rates, aesthetic and functional outcomes, and biological response.

Ciencia y evolución del dióxido de zirconio, de la prioridad mecánica a la necesidad estética

Article

Full-text available

Oct 2020

Objetivo : Identiﬁcar las publicaciones recientes de los materiales de restauración a base de dióxido de zirconio que incluyan estudios clínicos, propiedades mecánicas, físicas y estéticas, así como su evolución, manufactura y diversas aplicaciones en la práctica clínica diaria. Material y métodos : La búsqueda sistemática de la literatura se realizará en las bases de datos de PubMed y Ebsco, se considerarán publicaciones del 2010- 2019 y que fueran investigaciones clínicas, laboratoriales y todas aquellas que mostraban la evolución en el tiempo del dióxido de zirconio, así como su aplicabilidad y diversiﬁcación. Resultados: Se revisaron 48 artículos que cumplieron con los criterios de selección para la revisión bibliográﬁca. Se encontró que todas las restauraciones protésicas a base de dióxido de zirconio, indistintamente a su forma de utilización, mostraron un desempeño clínico muy similar a los tres años, después de ese tiempo, dependerá del tipo de utilización, composición y elección del caso. Conclusiones: El éxito clínico de las restauraciones en base a dióxido de zirconio, es debido a las múltiples ventajas mecánicas y, con las recientes modiﬁcaciones estructurales, sumadas al agregado de aditivos para su estabilización, se perﬁla como un material idóneo para el trabajo tanto en zonas estéticas como en áreas de necesidad de soporte mecánico con carga funcional elevada.

An Overview of the Current Survival Status and Clinical Recommendation for Porcelain Fused to Metal vs All-ceramic Zirconia Posterior Fixed Partial Dentures

Article

Apr 2017

Karishma V Vijan

Porcelain fused to metal (PFM) restorations has shown promising results in terms of longevity over decades. However, due to the paradigm shift with the preferences of both the patients and clinicians toward all ceramic restorations, these prostheses are being increasingly used in posterior region. Zirconia is one of the popular materials in dentistry today; it has good mechanical strength and has shown remarkable results in shortterm studies from 3 to 5 years. However, zirconia aging and chipping are most common causes of zirconia failure, besides loss of retention has also been reported in some studies. Nonetheless, there are no substantial studies that decipher the longevity of these restorations over a longer period of time. Moreover, it has been reported that zirconia cannot be used in areas of higher stresses. This review article compares the promising ceramic material zirconia and PFM restorations in terms of longevity and esthetics based on the present studies. An electronic search was conducted across Ovid Medline, complemented by manual search across individual databases, such as Cochrane and Google Scholar for literature analysis on PFM restorations, zirconia crowns, and fixed partial dentures (FPDs). The studies were reviewed and results were compared for the same. This paper summarizes the current scientific and clinical opinion through a brief review regarding the preferred material for posterior crowns and FPDs. It denotes that case selection and certain other factors can play a role in success of the zirconia prosthesis. How to cite this article Vijan KV. An Overview of the Current Survival Status and Clinical Recommendation for Porcelain Fused to Metal vs All-ceramic Zirconia Posterior Fixed Partial Dentures. World J Dent 2017;8(2):145-150.

Retrospective Long-Term Survival Rate and Clinical Performance of Zirconium Oxide Restorations over the Past 5 Years: A Comparative Study Between Single Crowns and Fixed Dental Prostheses

Article

Full-text available

Jan 2025
MED LITH

Background and Objectives: This five-year retrospective study evaluated the survival and clinical performance of 1143 zirconium oxide restorations, including both monolithic (144) and layered (999) restorations. Materials and Methods: The analysis included clinical records and follow-up data of patients treated with zirconium oxide restorations. Failures in layered restorations were examined, particularly focusing on chipping caused by unsupported feldspathic ceramic exceeding 1.5 mm. Monolithic restorations were used as a benchmark for durability. Results: The results demonstrated a high overall survival rate of 96.3%, with monolithic restorations achieving a perfect survival rate of 100%, while layered restorations had a survival rate of 95.8%. Failures in the layered restorations were primarily associated with chipping, especially when the unsupported feldspathic ceramic exceeded 1.5 mm. Conclusions: This finding highlights the importance of maintaining adequate support for the ceramic layer to prevent such complications. Monolithic restorations, in contrast, showed superior durability, with no failures reported, making them a more reliable option for long-term success. These findings emphasize the need for the careful selection of zirconium oxide restoration types based on the clinical context, particularly in cases where durability is critical.

Zirconia in fixed prosthodontics: a review of the literature

Article

Nov 2024

The purpose of this narrative review is to organize information and knowledge about the properties of the clinical evidence of zirconia-applied dental restorations and to provide relevant information to establish application methods to obtain long-term clinical prognosis of zirconia-applied dental prostheses. From PubMed and manual searches, found “zirconia,” “crown,” “survival,” and “success” keywords were searched. Case reports, case series, reviews, abstracts, in vitro studies, and observational studies were excluded. Additionally, implant superstructures not supported by the periodontal ligament and partially covered crowns were excluded. A total of 42 studies were identified. According to the studies in this review, the most common complication of porcelain-layered zirconia restorations is porcelain fracture, but the long-term prognosis is stable. However, complications of monolithic zirconia restorations include crown fractures and fractures of the abutment tooth and root, and long-term clinical evidence is not available yet. Additionally, bruxism can be a complication factor with both types of restorations, so it is important to carefully examine the oral habits, including bruxism, before treatment. Therefore, the success of zirconia-based restorations in clinical practice requires a careful approach in addition to accurate knowledge of the zirconia material and identification of applicable cases.

Clinical Outcome of Indirect Bonded Porcelain Restoration Versus Full-Coverage Crown on Endodontically Treated Teeth in Posterior Areas: A Systematic Review

Article

Full-text available

Sep 2024

The significant loss of tooth structure that occurs after dental caries and endodontic therapy is a common clinical challenge. Several methods were discussed in the literature to treat badly damaged teeth. This systematic review aims to compare the clinical outcomes of partial indirect bonded porcelain restorations to full-coverage crowns of endodontically treated teeth in posterior areas. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Data included in the review were identified through bibliographic research on electronic databases (PubMed/Medline, Google Scholar, Cochrane Library, and Web of Science). The strategy was applied by searching for randomized clinical trials (RCTs), cohort studies, and case-control studies using keywords (partial indirect bonded porcelain restoration, partial indirect bonded restoration, inlay and onlay, full convergent crown, and ceramic crown). As a result of a literature search through selected databases using the keywords, 88,421 papers were identified. A total of 671 articles were related and screened for inclusion and exclusion criteria. Four hundred and eighty-two articles that did not meet the inclusion criteria were excluded. A total of 189 full-text papers were assessed, and 20 articles were included in this study. Nineteen cohort studies and one case-control study were included and assessed in this review. This study concludes that both full-coverage crowns and partial indirect bonded restorations demonstrate comparable survival rates. However, limited studies exist regarding partial indirect bonded restorations on endodontically treated teeth, indicating the need for further updated studies.

In Vitro Evaluation of Occlusal Thickness On the Fracture Resistance of CAD-CAM Monolithic Zirconia Molar Crowns

Article

Full-text available

Jan 2023

Background and objectives. Many dental practitioners have always struggled with obtaining aesthetic restorations while preserving the remaining dental structure. The purpose of this study is to investigate the relationship between the occlusal thickness and fracture resistance of CAD/CAM monolithic zirconia restorations to determine the feasibility of reducing the occlusal thickness, particularly in the posterior area, where inter-occlusal space is typically limited and high biting forces are applied. Methods. Four experimental groups were created using thirty-two CAD-CAM monolithic zirconia crowns with different occlusal thicknesses: 2.0 mm (group 1), 1.5 mm (group 2), 1.0 mm (group 3), and 0.5 mm (group 4). Self-adhesive resin cement was used to cement the restorations to human molars. Loading the specimens until fracture occurred, and the fracture resistance and mode of failure were recorded. The data were statistically analyzed using a one-way ANOVA followed by Fisher's exact test. Results. All specimens' fracture resistance values exceeded the maximum physiological occlusal loads in molar areas, and all of the crowns had consistent microcracks. A complete fracture was only interested in one crown with a thickness of 0.5 mm. Conclusion. The occlusal thickness of CAD-CAM monolithic zirconia crowns can be decreased to 0.5 mm while still being strong enough to sustain occlusal loads.

http://journals.khalijedental.com.ly/index.php/ojs/article/view/55

Article

Full-text available

Jun 2023

Enas Khamakhim

Effect of Surface Treatment and Micro Shear Protocol on Bond Strength to Yttrium‑Stabilized Tetragonal Zirconia

Article

Full-text available

Jul 2023

Effect of Multiple Firings on the Microshear Bond Strength Between a Translucent Zirconia and a Resin Cement

Article

Full-text available

Feb 2023
OPER DENT

Purpose: This study investigated the microshear bond strength between a resin cement and a translucent zirconia subjected to multiple characterization firings. Methods and materials: 5Y-PSZ zirconia blocks (Katana UTML) were sliced, sintered (1550°C, 2 h), and randomly divided into six groups (n=10) according to the number of characterization firings (0, 1, 2, 3, 5, or 10) and aging (baseline or after thermocycling). Each characterization firing was performed at 750°C for 1 minute. The ceramic surfaces were all sandblasted with 50 μm Al2O3 and silanized. Then, cylinders of resin cement (0.96 mm diameter × 2 mm height) were bonded onto their surfaces. The baseline samples were immersed in distilled water for 24 hours before the microshear bond strength (μSBS) tests. The aged samples were tested after 5000 thermocycles in water (5°C-55°C). The failure modes were classified as adhesive, predominantly adhesive, or cohesive. Scanning electron microscope images of the failure modes and the ceramic surfaces after the firings were taken. The μSBS data were analyzed by twoway ANOVA and Tukey's test. Results: The number of characterization firings and aging affected the bond strength. The highest bond strength values were observed from the 2-firing group at baseline. The μSBS results after 1, 2, or 3 characterization firings were similar at baseline and after aging. On the other hand, 0, 5, and 10 firings revealed the lowest bond strengths. The most frequent failures were adhesive and predominantly adhesive. Zirconia grains were not affected by the multiple firings. Conclusion: One to three characterization firings after sintering improve the bond strength of 5Y-PSZ to the resin cement when compared to none or several (five or ten) firing cycles.

Survival and success of veneered zirconia crowns: A 10-year follow up study

Article

Jan 2023
Int J Comput Dent

Aim: This study's purpose was to evaluate the long-term clinical survival and success rate of veneered zirconia crowns with a modified anatomical framework design after 10 years in function. Materials and methods: In total, 36 zirconia crowns were fabricated for 28 patients. An anatomically modified framework design was developed. Crowns were inserted between the years 2008 and 2009. A follow-up of 19 patients with 28 crowns was conducted in 2020 to document mechanical and biologic parameters. Additionally, a modified version of the pink esthetic score (PES) was collected. Patient satisfaction was assessed using United States Public Health Service (USPHS) criteria. The success and survival rates were calculated using the Kaplan-Meier analysis. Results: After more than 10 years of clinical service, the zirconia crowns' survival rate was 92.9%. Biological complications occurred in 12% of crowns, whereas technical complications occurred in 54% of the examined crowns. Mostly, chippings (50%) and insufficient marginal gaps (50%) were observed. Most crowns were positively evaluated for more than one technical complication. Periodontal conditions with probing depths up to 3 mm were comparable to measured values before crown delivery (73-75%). Most of the crowns had modified PES values of 10 or higher. Patients' satisfaction was high. Conclusion: The modified framework design leads to crowns' high survival rate but relatively low success rate. High patient satisfaction and inconspicuous periodontal conditions were demonstrated. Biological complications occur far less frequently than technical complications.

Differences between ceramic and porcelain laminate veneers

Article

Full-text available

Dec 2022

In dental care, treating anterior dentition esthetically has always been difficult. Numerous restorative solutions, including resin composites, all-ceramic crowns, and ceramic veneers, become accessible with the advancement of dental materials. In such situations, practitioners and patients should pick the most appropriate option to enhance oral health and aesthetic outcomes. Any substance made of non-metallic inorganic matter and fired at an elevated temperature is referred to as ceramics (pyrochemical process). Ceramics called glass ceramics are those that commence in a glassy phase and later devitrify to a partly or wholly crystalline form. Dental ceramics that most closely optically resemble the characteristics of real teeth are primarily glassy materials, which are derived primarily from triaxial porcelain compositions of feldspar, quartz, and kaolin. Glass-ceramics possess much more toughness and strength than porcelain but are also less translucent. Tougher and more durable ceramics, primarily yttrium stabilized tetragonal zirconia polycrystals, have been developed recently (Y-TZP). Due to its limited translucency, Y-TZP presents a major drawback. A significant amount of current tooth structure must be removed in order to allow for a porcelain veneer that is wide enough to overlay an opaque zirconia base and replicate the optical characteristics of the surrounding natural teeth. Ceramic restoration effectiveness, in the end, relies on the material choice, production process, and restoration strategy.

Bonding ceramic restorations

Article

Jan 2019

Silica deposition on zirconia via Room-Temperature Atomic Layer Deposition and bond strength to resin-based luting agent

Article

Jun 2022
CERAM INT

To evaluate the effect of the controlled growth of yttria-stabilized zirconia (Y-PSZ) transformed layer and silica deposition via Room-Temperature Atomic Layer Deposition (RT-ALD) on the shear bond strength (SBS) between Y-PSZ and luting agent. Y-PSZ specimens (IPS e.max ZirCAD) with different translucencies (MO, MT, LT) were exposed to surface treatments (n = 10): control (C - no treatment), aged (A - 15 h, 134 °C, 2 bar in autoclave), blasted (B - 50 μm Al2O3), silica deposition via RT-ALD (R - 40 cycles of sequential exposure to tetramethoxysilane orthosilicate and ammonium hydroxide vapors) and aged followed by silica deposition (AR). Specimens were bonded to resin composite cylinders with a luting agent (Multilink Automix) and SBS test was performed. Failure mode and surface chemical and topographical characterization (energy-dispersive spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy) were performed. SBS data was analyzed by two-way ANOVA and Tukey test (α = 0.05). Silica deposition resulted in SBS values similar to alumina blasting (p > .848), with no significant effect of aging (p > .664). Higher incidence of composite resin cohesive failures was observed in the R-treated specimens (MT, LT), with and without aging. SEM images showed a rougher surface for B-treated specimens, while no changes were observed for the other treatments. XPS analysis showed a nanofilm of silica deposited over the zirconia surface after silica deposition. RT-ALD was an effective technique to deposit silica on the surface of zirconia, generating bond strength results similar to alumina-blasted specimens.

Retrospective clinical study of tooth‐supported single crowns: A multifactor analysis

Article

Full-text available

May 2022

The purpose of the study was to investigate the influence of multiple factors on the survival of tooth‐supported single crowns and assess the biological and technical complications. This retrospective study included patients rehabilitated with single crowns with a minimum follow‐up time of 6 months after delivery. The cumulative survival rate was calculated over the maximum period of follow‐up time and reported in a life‐table survival analysis. Univariate and multivariate Cox regression was used to evaluate the associations between clinical covariates and crown failure. The included cohort group consisted of 1037 single crowns delivered in 401 patients and followed for a mean of 134.8 ± 80.2 months. Cumulative survival rate was 89.9% and 80.9% after 5 and 10 years and 70.5% and 61.8% after 15 and 20 years, respectively. The main reasons for single crown failure were loss of retention, tooth loss, and fracture. Anterior placement, non‐vital abutments, and bruxism significantly influenced the survival of single crowns. The survival of single crowns was not influenced by patient's age and sex, location of the crowns in relation to the jaws, type of tooth, presence of post and core, and type of crown material, treatment providers, or smoking. Anterior placement, non‐vital abutments, and bruxism are factors suggested to increase the risk of single crown failure and the prevalence of technical and biological complications.

Which Zirconia Surface-cleaning Strategy Improves Adhesion of Resin Composite Cement after Saliva Contamination? A Systematic Review and Meta-Analysis

Article

Apr 2022

Purpose: To identify the most effective cleaning method for saliva-contaminated zirconia surface before adhesive cementation through a systematic review and meta-analysis. Materials and methods: PubMed, Scopus, and Web of Science databases were searched to select in vitro studies published through October 2021. Studies that did not perform aging methods, had a sample size less than 5 per group, or did not present a group with zirconia contaminated only with saliva were excluded. Data were extracted and risk of bias was assessed. Statistical analysis comparing the cleaning methods was conducted, and the standardized mean difference was assessed using the R software program. Results: Among 804 potentially eligible studies, 36 were selected for full-text reading, of which 13 were included in qualitative analysis, and 11 of these were subsequently included in the quantitative analysis. A meta-analysis revealed a significant difference in the bond strength between the cleaning methods. Sandblasting with Al2O3 showed a higher bond strength than cleaning solution (Ivoclean, Ivoclar Vivadent) (p < 0.01, I2 = 65%), and both methods promoted higher resin-bond strength to zirconia than water cleaning. In addition, there was no significant difference in the bond strength between alcohol (p = 0.35, I2 = 79%), phosphoric acid (p < 0.23, I2 = 90%), and water cleaning. Conclusion: Sandblasting with Al2O3 seems to be the best method for zirconia surface cleaning before adhesive luting, promoting better resin-bond strength to zirconia.

Effect of different endodontic access preparations on the biomechanical behavior of lithium disilicate and resin nanoceramic onlay restorations: An in vitro and 3D finite element analysis study

Article

Full-text available

Feb 2022
J PROSTHET DENT

Statement of problem The effect of different sizes of endodontic access preparations on the performance of lithium disilicate glass-ceramic and resin nanoceramic onlay restorations is unclear. Purpose The purpose of this in vitro and 3D finite element analysis study was to assess the effect of a conservative endodontic access cavity and a traditional endodontic access cavity on the fracture resistance and stress distribution of lithium disilicate glass-ceramic and resin nanoceramic onlays. Material and methods Sixty caries-free human mandibular molars were anatomically prepared for onlays and divided into 6 groups. After restoration with a lithium disilicate glass-ceramic (N=30) or resin nanoceramic (N=30), each material was further divided into traditional or conservative endodontic access cavity or intact tooth groups. After endodontic therapy and thermocycling, all specimens were submitted to a cycle fatigue test and then loaded until fracture. Failure type and location after debonding or fracture were classified and recorded. Furthermore, stress distribution in the 6 models was analyzed by using a finite element analysis software program. The data were compared by using a 2-way ANOVA test and the Tukey post hoc test (α=.05). The Weibull modulus and Weibull failure probabilities were also estimated for each group. Results The lithium disilicate glass-ceramic onlays had lower fracture resistance values than the resin nanoceramic onlays in both the traditional and conservative endodontic access cavity groups (P<.05). The fracture resistance of the 2 materials for onlays with endodontic access was significantly lower than that for the intact restorations (P<.05). No significant difference was found between the fracture resistance of Lava Ultimate restorations with traditional endodontic access and conservative endodontic access, while the fracture resistance of EMAX restorations with traditional endodontic access was significantly lower than that of restorations with conservative endodontic access (P<.05). A higher percentage of irreparable fractures was found in the 3 resin nanoceramic restoration groups. The von Mises stresses were higher in the lithium disilicate glass-ceramic restorations than in the resin nanoceramic restorations with the same access cavities. The von Mises stresses in the tooth structure were higher with the resin nanoceramic restorations than with the lithium disilicate glass-ceramic restorations with the same access cavities. Conclusions An endodontic access cavity had more influence on the lithium disilicate glass-ceramic onlays than on the resin nanoceramic onlays, and a traditional endodontic access cavity significantly decreased the fracture resistance of lithium disilicate glass-ceramic onlays.

Retensjon av sementerte protetiske erstatninger

Article

Full-text available

Jun 2021

Hovedbudskap Ingen enkelt sement på markedet i dag dekker alle indikasjonsområder. Riktig diagnostikk og kunnskap om interaksjoner mellom forskjellige protesematerialer, sement- og tannvevstyper er forutsetninger for å velge riktig sement i en gitt behandlingssituasjon. Kliniske momenter som ligger til grunn for valg av riktig sement er, i kronologisk rekkefølge, vurdering av resttannsubstans, valg av restaurering og utforming av tannprepareringen, valg av restaureringsmateriale (metall, keram, polymer), en egnet overflatebehandling av resttannvev og protese og en vurdering av passform og bredde på sementspalten. Det er viktig å kjenne til ulike egenskaper ved sementer og å overholde korrekte arbeidsprosedyrer i henhold til faglige normer og produsentenes bruksanvisninger.

Assessment of final shade and translucency of two monolithic zirconia versus veneered zirconia on a dark substrate. An Invitro study

Article

Apr 2021

Fracture strength of CAD/CAM Zirconia Fixed Dental Prostheses with different connector surface areas

Article

Full-text available

Jan 2021

ABSTRACT Background: Connectors of zirconia fixed dental prostheses (FDPs) play an important role in the fracture resistance of prostheses. The current study aimed to investigate the influence of connector dimensions on the fracture resistance of zirconia FDPs when cemented with two different types of cement. Methods: Sixty resin casts were divided into two main groups according to the length span of the zirconia FDPs: 3-unit (3U) and 4-unit (4U) FDPs. Each group was divided into three subgroups according to the connector surface area as follows: Subgroup U9 with surface area of 9 mm2 of each connector, Subgroup U12 with a surface area of 12 mm2 each connector, and Subgroup U16 with a surface area of 16 mm2 of each connector was 16 mm2. Each subgroup was divided into two subgroups according to the type of cement. Specimens were loaded in a universal testing machine, and data were statistically analyzed using 3-way analysis of variance (α = 0.05). Results: The results showed that mean fracture resistance was significantly increased by increasing connector surface area (p < 0.001). The 3-unit fixed dental prostheses (FPDs) gave higher statistically significant fracture load values than 4-unit FPDs (p < 0.001). However, the cement type had no influence on the fracture resistance of zirconia FDPs. Conclusion: The fracture strength of the zirconia FDPs was affected by the connector dimension. The 3-unit connector design was able to withstand occlusal forces more than the 4-unit connector design. Also, the 3-connector design with a cross-section of 16 mm2 was more able to withstand occlusal forces than those with the dimensions of 12 and 9 mm2 . Keywords: Fixed dental prostheses, fracture strength, CAD/CAM, connector, resin cement, zinc phosphate cement.

Metal-ceramic partial fixed dentures: a retrospective study

Article

Full-text available

Nov 2020

Objective Metal-ceramic prosthesis are the treatment of choice in oral rehabilitation because of their high survival rates. However, there are few reports in the scientific literature about factors that lead to fractures of metal-ceramic prostheses. The aim of this study was to evaluate whether prostheses units number, abutment type and number, type of the prostheses, prostheses position in the mouth, bruxism and occlusal plaque influence the incidence of fractures in fixed metal-ceramic prostheses. Methods For this study, 16 patients were selected, totaling 74 metal-ceramic prostheses installed between 2000-2010, with follow up of at least four years. Besides dental history, other information was collected, such as patients’ gender and age, prostheses installation date, and the ceramic system used. In case of prostheses fracture, a questionnaire was applied to identify signs of bruxism. A clinical evaluation was done to evaluate the prostheses integrity and opposing dentition characteristics. Success, failure and survival rates were determined. Results The results showed that the success rate of metal-ceramic prostheses was 87.8% and the survival rate was 89.1%. In addition, the success rate was independent of patient age, prostheses installation time, number of prosthesis, number of prosthesis’ units and abutments. The qualitative variables also did not show significant statistical results between success and failure rates. Conclusion It was concluded that metal-ceramic prostheses have high success and survival rates, what guarantees longevity and indication of this type of prostheses in daily practice.

Comparison of 16.9-year survival of pressed acid etched e.max lithium disilicate glass ceramic complete and partial coverage restorations in posterior teeth: Performance and outcomes as a function of tooth position, age, sex, and thickness of ceramic material

Article

Full-text available

Sep 2020

Statement of problem: Long-term clinical data are lacking on the comparison of the survival of adhesively luted pressed e.max lithium disilicate glass ceramic complete and partial coverage restorations in posterior dentitions and the effect that different technical and clinical variables have on their survival. Purpose: The purpose of this clinical study was to examine and compare the 16.9-year survival of posterior pressed e.max lithium disilicate glass ceramic complete and partial coverage restorations and associated clinical parameters on the outcome. Material and methods: Patients requiring either single-unit posterior defect-specific partial coverage or complete coverage restorations were recruited in a clinical private practice. The participants were offered the options of direct restorations, partial coverage cast gold, or glass ceramic (lithium disilicate) restorations. Those requiring complete coverage restorations were given the options of complete cast gold, metal-ceramic, or glass ceramic restorations. Only participants who chose glass ceramic partial and complete coverage restorations were included in the study. The overall survival of the glass ceramic restorations was assessed by the clinical factors determined at recall. The effect of various clinical parameters (type of restoration, dental arch, tooth position in the dental arch, age and sex of participant, and ceramic thickness) was evaluated by using Kaplan-Meier survival curves to account for attrition bias and other reasons for failure. The statistical significance of differences between parameters was determined using the log rank test (α=.05). Results: A total of 738 participants requiring 2392 lithium disilicate restorations in posterior teeth were evaluated. The mean age of the participants at the time of restoration placement was 62 (range: 20-99 years, 302 men and 436 women). Of 2392 units, 1782 were complete and 610 were partial coverage restorations. A total of 22 failures (bulk fracture or large chip) requiring replacement were recorded with the average time to failure 3.5 (0.02-7.9) years. The total time at risk computed for these units was 13227.9 years, providing an estimated failure risk of 0.17% per year. The 16.9-year estimated cumulative survival was 96.49%. The estimated cumulative survival of posterior complete (n=1782) and posterior partial coverage restorations (n=610) was 96.75% at 10.5 years and 95.27% at 16.9 years (P<.05). Of the 22, 16 failures were recorded for the complete coverage restorations. The total time at risk for these restorations was 10144.5 years, providing an estimated risk of 0.16 per year. The other 6 failures recorded occurred for the partial coverage restorations. The total time at risk for these restorations was 3083.5 years, providing an estimated risk of 0.19% per year. No statistically significant difference was found in the survival of posterior complete and partial coverage restorations among men and women, different age groups, or posterior tooth position in the dental arch (P>.05). The thickness of the restoration also had no influence on the survival of glass ceramic posterior restorations (P>.05). Conclusions: Pressed e.max lithium disilicate complete and partial coverage restorations showed high survival rates in posterior teeth over a 16.9-year period, with an overall failure rate of 0.17% per year. Risk of failure at any age was low for both men and women. No statistically significant difference was found in the survival of complete and partial coverage restorations, and none of the confounding variables, including the thickness of the restoration, appeared to have a significant effect on survival.

Investigation of the Effects of Cement in Different Thicknesses and Mechanical Properties on Implant with Zirconia Crown: A Finite Element Analysis

Article

Oct 2020

Aim: To evaluate the stress distribution in the implant-supported mandibular premolar monolithic zirconia crowns with different cement types and thicknesses under constant masticatory force using three-dimensional (3D) finite element analysis (FEA). Materials and Methods: The 3D models of monolithic zirconia crowns, which were cemented on abutment, were generated. Nine numerical models were fabricated by applying different cement thicknesses (0.02, 0.05, and 0.10mm). The solid models were imported into the FEA software and meshed into tetrahedral elements. All models were simulated under masticatory force loads of 100N at two points, respectively. Results: Stress distribution was affected by cement thickness. When the solutions of total deformation on crown were examined, it was observed that Cement-1 with a thickness of 0.02mm showed the lowest value (0.07mm). It was shown that the use of Cement-2 material with a thickness of 0.02mm provides the lowest maximum principle stress on abutment (4.90MPa). When the stresses on the implant were examined, it was determined that the lowest stress values were again formed in cements with a thickness of 0.02mm (130MPa). The results showed that 0.05 mm thick High Modulus Resin Adhesive Cement (Panavia, Kuraray, Tokyo, Japan) gave the lowest strain values. Conclusion: It was observed that the different resin and cement thicknesses played an important role in the stresses on the zirconia crown, abutment, and implant. Cement thickness has also been evaluated as an important factor, affecting the material life and leading to the preservation of recovery.

Retentive Strengths for Prefabricated Primary Molar Zirconia Crowns Using Five Different Cements

Article

Full-text available

Dec 2018

Purpose: To assess retentive strengths of 5 commercially available cements with prefabricated primary molar zirconia crowns. Methods: Seventy ve prefabricated primary molar zirconia crowns were cemented on extracted human teeth using 5 di erent cements (Ketac Cem Maxicap, FujiCEM 2, BioCem, RelyX Unicem 2 and RelyX Luting Plus Automix N=15 per group). Following thermocycling, 5000 cycles from 5º to 55º C, crown retentive strengths data were collected and statistically analyzed using one-way ANOVA with LSD post hoc test (P <0.05). Results: Mean retentive strengths are: Ketac Cem 482.4N 87, FujiCEM 2 354.9N 121, BioCem 462.7N 138, RelyX Unicem 2 409.0N 171 and RelyX Luting 233.5N 170. e retentive strengths were statistically signi cant (P=0.014) among the 5 groups, but not the cement failure rankings (P=0.47). Conclusions: There is a significant difference in the retentive strengths for cementing prefabricated primary molar zirconia crowns among the 5 different cements. Ketac Cem has the highest retention force, followed by BioCem, RelyX Unicem, Fuji CEM II, and RelyX Luting. e majority of cement failures occurred between the cement and the tooth.

EFFECT OF MATERIAL TYPE ON THE STRESS DISTRIBUTION IN POSTERIOR THREE-UNIT FIXED DENTAL PROSTHESIS: A THREE-DIMENSIONAL FINITE ELEMENT ANALYSIS

Article

Oct 2018

Mazen A. Attia

Fracture resistance assessment of endodontically accessed hybrid ceramic crowns repaired with two different protocols

Article

Jan 2018

The Marginal Fit and Fracture Resistance of Four‑Unit Monolithic and Bi -layered Zircon Fixed Dental Prosthesis

Article

Jan 2020

Amany Korsel

Effect Of Non-Thermal Air Plasma Treatment On Shear Bond Strength Of Adhesive Resin Cement To Zirconia

Article

Full-text available

Jul 2018

EFFECT OF CONNECTOR SURFACE AREA AND TYPE OF CEMENT ON FRACTURE RESISTANCE OF FULL CONTOURED MONOLITHIC CAD CAM ZIRCONIA FIXED PARTIAL DENTURES

Article

Jul 2017

Effect of Aging and Pre-sintering Surface Treatment of Zirconia Cores on Chipping of Veneered Zirconia Crowns

Article

Nov 2019

Monolithic Zirconia: An Update to Current Knowledge. Optical Properties, Wear, and Clinical Performance

Article

Full-text available

Sep 2019

The purpose of this paper was to update the knowledge concerning the wear, translucency, as well as clinical performance of monolithic zirconia ceramics, aiming at highlighting their advantages and weaknesses through data presented in recent literature. New ultra-translucent and multicolor monolithic zirconia ceramics present considerably improved aesthetics and translucency, which, according to the literature reviewed, is similar to those of the more translucent lithium disilicate ceramics. A profound advantage is their high strength at thin geometries preserving their mechanical integrity. Based on the reviewed articles, monolithic zirconia ceramics cause minimal wear of antagonists, especially if appropriately polished, although no evidence still exists regarding the ultra-translucent compositions. Concerning the survival of monolithic zirconia restorations, the present review demonstrates the findings of the existing short-term studies, which reveal promising results after evaluating their performance for up to 5 or 7 years. Although a significant increase in translucency has been achieved, new translucent monolithic zirconia ceramics have to be further evaluated both in vitro and in vivo for their long-term potential to preserve their outstanding properties. Due to limited studies evaluating the wear properties of ultra-translucent material, no sound conclusions can be made, whereas well-designed clinical studies are urgently needed to enlighten issues of prognosis and long-term survival.

Does the bond strength of highly translucent zirconia show a different dependence on the airborne-particle abrasion parameters in comparison to conventional zirconia?

Article

Full-text available

Aug 2019

Purpose: To compare the effects of airborne-particle abrasion protocols on the surface morphology, the phase transformation and the resin bond strength of highly translucent zirconia (M) and conventional zirconia (Z). Methods: Thirteen groups (N = 12) of Z and M specimens were prepared. Except for the control group, the specimens were sandblasted with conditions involving different grit sizes (50 μm or 110 μm), treatment times (10 s or 20 s) and pressures (0.1 MPa, 0.3 MPa or 0.6 MPa). The surface morphology was analyzed using scanning electron microscope (SEM) and the phase analysis was conducted with X-ray diffraction (XRD). The Ra and the shear bond strength (SBS) were measured and statistically analyzed, and the failure mode was determined by optical microscope. Results: The surface morphologies were strongly dependent on treatment conditions. Larger particle size and higher pressure resulted in higher Ra for both materials. Longer blasting time resulted in higher Ra for Z but not M. Overall, the SBS increased with increasing Ra; the highest average SBS was achieved by M and exceeded 18 MPa. The monoclinic transformation was not found in any treatment for M, but was found in Z. Conclusions: Z and M showed different dependence on the airborne-particle abrasion parameters in terms of Ra, SBS and phase transformation. The conditions for maximizing SBS included a 110 μm particle size and 20 s treatment for both, with pressures of 0.3 MPa and 0.6 MPa for the M and Z, respectively.

Influence of surface treatments on highly translucent zirconia: Mechanical, optical properties and bonding performance

Article

Jan 2025
J DENT

Over 14-year survival of pressed e.max lithium disilicate glass-ceramic complete and partial coverage restorations in patients with severe wear: A prospective clinical study

Article

Jul 2024

Nacre-like ceramic composites: Properties, functions and fabrication in the context of dental restorations

Article

Nov 2023
ACTA BIOMATER

Clinical evaluation of zirconia crowns cemented with two different resin cements: A retrospective study

Article

Aug 2023
J ORAL REHABIL

Background: Self-adhesive resin cement has been used extensively with zirconia crowns. Several in vitro studies showed that adhesive resin cementation may increase zirconia crowns' retention and their fatigue resistance. Objectives: This retrospective study aimed to evaluate the clinical performance, survival and success rates and complications encountered with zirconia crowns cemented with two different self-adhesive resin cements. Methods: A total of 112 patients who received 176 monolithic zirconia crowns were evaluated. Crowns were cemented with RelyX Unicem 2 (n = 74) and Panavia SA (n = 102) self-adhesive resin cements. Clinical assessments of the crowns and supporting periodontal structures were performed following the modified California Dental Association (CDA) criteria. Intraoral photographs and periapical and bitewing radiographs were obtained for further assessment by two evaluators. Descriptive statistics, McNemar, t-test, log rank (Mantel-Cox) tests and Kaplan-Meier survival analyses were performed (a = .05). Results: The 5-year survival and success rates were 100% and 96.4%, respectively. The complications encountered were recurrent caries (2.2%) and the need for endodontic treatment (0.5%). No technical complications, such as fracture or loss of retention, were observed. The type of cement and patient-related factors did not influence the survival and success rates of the crowns. Conclusions: Survival rate of zirconia crowns cemented with two different self-adhesive resin cements was 100% after 5 years.

Clinical outcomes of tooth-supported monolithic zirconia vs. porcelain-veneered zirconia fixed dental prosthesis, with an additional focus on the cement type: a systematic review and meta-analysis

Article

Full-text available

Aug 2023
CLIN ORAL INVEST

Purpose To compare the failure rates and the prevalence of technical complications between full-coverage tooth-supported monolithic zirconia (MZ) and porcelain-veneered zirconia (PVZ) fixed dental prosthesis, based on a systematic literature review. Methods An electronic search was performed in three databases, supplemented by hand searching. Several statistical methods were used. Results Seventy-four publications reported 6370 restorations (4264 PVZ; 2106 MZ; 8200 abutment teeth; 3549 patients), followed up until 152 months. A total of 216 prostheses failed, and survival was statistically significant different between groups. PVZ had higher occurrence of complications than MZ; the difference was especially greater for either minor or major chipping. The difference in prevalence of either minor or major chipping was statistically significant for PVZ prostheses between cementation with glass ionomer and adhesive resin cement (higher), adhesive resin and resin-modified glass ionomer cement (RMGIC, higher), and between RMGIC (higher) and glass ionomer cement. For MZ the difference was significant only for minor chipping between RMGIC (higher) and adhesive resin cement. Abutment teeth to PVZ prostheses more often lost vitality. Decementation was not observed with RMGIC. Air abrasion did not seem to clinically decrease the decementation risk. The 5-year difference in the occurrence of minor or major chipping between MZ and PVZ prostheses was statistically significant, but nor for catastrophic fracture. Conclusion Tooth-supported PVZ prostheses present higher failure and complication rates than MZ prosthesis. The difference in complications is striking when it comes to chipping. Clinical relevance Awareness of the outcome differences between different types of zirconia prostheses is important for clinical practice.

Traditional versus conservative endodontic access impact on fracture resistance of chairside CAD‐CAM lithium disilicate anterior crowns: An in vitro study

Article

Full-text available

Dec 2022

Purpose: To evaluate the effect of traditional and conservative endodontic access hole preparation on fracture resistance of chairside computer-aided design and computer-aided manufacturing (CAD-CAM) lithium disilicate maxillary right central incisor crowns. Materials and methods: Fifty-seven milled lithium disilicate maxillary right central incisor crowns were designed and fabricated with a chairside CAD-CAM system (Planmeca Romexis, Planmeca). The abutment preparation had a 1.0 mm incisal reduction and 1.0 mm chamfer finish. The restorations were bonded with resin cement to printed resin dies (n = 19 per group) and were treated and divided into three groups, 1) no endodontic access, 2) traditional triangular endodontic access, and 3) conservative ovoidal endodontic access. The endodontic access of the crowns was sealed with flowable resin composite. Restorations were subjected to 10,000 cycles of thermal cycling between 5° and 55°C. Then, restorations were loaded and exposed to compressive loading force, and the crack initiation (CI) and complete fracture (CF) were recorded. SEM micrographs of broken specimens on the printed dies were captured. ANOVA test and Bonferroni's correction were used for statistical comparison. Results: The fracture resistance among the three groups varied. Crowns with no endodontic access displayed significantly (p < 0.001) higher resistance [CI: 1025 (121) N; CF 1134 (127) N], followed by crowns with conservative ovoidal endodontic access [CI: 924 (60) N; CF: 1000 (72) N. Crowns with traditional triangular endodontic access showed the significantly (p < 0.001) lowest fracture resistance [CI: 635 (82) N; CF: 709 (75) N]. Conclusion: The fracture resistance of chairside CAD-CAM lithium disilicate maxillary anterior crowns is influenced by the type of endodontic access provided. Conservative ovoidal endodontic access provides crowns with higher fracture resistance than traditional triangular endodontic access. Crowns with no endodontic access provided the highest resistance than other types of endodontic access. HOW TO CITE THIS ARTICLE: Jurado CA, Amarillas-Gastelum C, Tonin BSH, Nielson G, Afrashtehfar KI, Fischer NG. Traditional versus conservative endodontic access impact on fracture resistance of chairside CAD-CAM lithium disilicate anterior crowns: An in vitro study. J. Prosthodont. 2022;1–7. https://doi.org/10.1111/jopr.13625

Fractographic analysis of 35 clinically fractured bi-layered and monolithic zirconia crowns

Article

Aug 2022
J DENT

Objectives : The aim of this retrieval study was to analyze the fracture features and identify the fracture origin of zirconia-based single crowns that failed during clinical use. Methods : Thirty-five fractured single crowns were retrieved from dental practices (bi-layered, n=15; monolithic, n=20). These were analyzed according to fractographic procedures by optical and scanning electron microscopy to identify fracture patterns and fracture origins. The fracture origins were closely examined. The crown margin thickness and axial wall height were measured. Results : Three types of failure modes were observed: total fractures, marginal semilunar fractures, and incisal chippings. Most of the crowns (23) had fracture origins at the crown margin and seven of them had defects in the fracture origin area. The exact fracture origin was not possible to identify due to missing parts in four crowns. The crown wall thickness was 20% thinner and wall height 30% shorter in the fracture origin area compared to the opposite side. Conclusions : The findings in this study show that fractography can reveal fracture origins and fracture modes of both monolithic and bi-layered dental zirconia. The findings indicate that the crown margin on the shortest axial wall is the most common fracture origin site. Clinical Significance : Crown design factors such as material thickness at the margin, axial wall height and preparation type affects the risk of fracture. It is important to ensure that the crown margins are even and flawless.

Longevity and failure mode of posterior ceramic crowns and fixed partial denture

Article

Full-text available

Apr 2022

Omir Aldowah

The purpose of this review is to analyse the longevity of posterior all-ceramic crowns and fixed partial dentures; in addition to determine the failure mode. It seeks to assess the risk factors that should be considered with posterior all-ceramic restorations. The review of literature revealed an acceptable longevity for posterior all-ceramic restorations in a 5-year follow up period. This accompanies their aesthetic outcome especially with improving of mechanical properties of glass ceramic by adding reinforcement crystalline phases or using core. The loss of vitality and secondary caries were the common biological complications while ceramic fracture and chipping were the most frequent mechanical complications. Also, the para-functional activity and using implant as an abutment increase the risk of failure especially on posterior teeth.

S3-Leitlinien-Update "Vollkeramische Kronen und Brücken" für die Praxis

Article

Feb 2022
Quintessenz

Für den Langzeiterfolg von vollkeramischen Restaurationen sind die Indikationsstellung, die Werkstoffauswahl, die Beachtung der Funktion sowie die Berücksichtigung von materialspezifischen Eigenschaften essenziell. Das im Juni 2021 veröffentlichte Update der S3-Leitlinie „Vollkeramische Kronen und Brücken“ (AWMF-Reg.-Nr. 083-012) zeigt einen Rahmen auf, innerhalb dessen vollkeramische Kronen und Brücken evidenzbasiert sicher angewendet werden können. Mit der Aktualisierung wurden alle Kapitel hinsichtlich neuer Forschungsergebnisse überarbeitet, die Empfehlungen auf Grundlage dieser Evidenz angepasst, die Anwendung neuer Werkstoffe ergänzt und um zusätzliche Indikationen erweitert. Zudem wurden Fragen zur vollkeramischen Versorgung von Bruxismuspatienten und zu werkstoffspezifischen Fertigungsempfehlungen evidenzbasiert beantwortet. Im vorliegenden Beitrag sollen die Leitlinienempfehlungen für die Praxis anwenderbezogen dargestellt werden.

The effect of endodontic access preparation on the failure load resistance of a 3Y‐TZP monolithic zirconia crown

Article

Jul 2021

The effect of endodontic access preparation on the failure load resistance of 3Y‐TZP zirconia crowns was accomplished by preparing human molars and luting monolithic zirconia crowns with a self‐adhesive resin cement. Besides the intact control, teeth received endodontic access preparations and then grouped (n = 12) into a positive control (no access repair), dentin core replacement only and complete access repair groups. Specimens were axially tested until failure with results of no significant difference between the failure load of intact controls and the complete access repair group. However, the positive control and dentin replacement only groups failed at significantly lower loads. Under the conditions of this study, there was no significant failure load difference between 3Y‐TZP monolithic zirconia crowns with repaired endodontic access preparations to that evidenced by an unprepared control. Although this evidence is encouraging, caution is advised and definitive recommendations cannot be made until verified by clinical studies.

Stomatology Edu Journal 2 2014

Book

Full-text available

Mar 2021

Marian-Vladimir Constantinescu

Monolithische CAD/CAM-Glaskeramik: Bruchlastergebnisse glasierter versus polierter Molarenkronen

Thesis

Jan 2019

Birte Loehr

Ziel der vorliegenden In-vitro-Untersuchung war es, die Auswirkungen unterschiedlicher Oberflächenbearbeitungen auf die Überlebensrate und die Bruchfestigkeit monolithischer, vollanatomischer Kronen aus zirkonoxidverstärktem Lithiumsilikat vor und nach Kausimulation mit thermodynamischer Wechsellast zu untersuchen. Es wurden insgesamt 40 identische monolithische ZLS-Kronen (Celtra Duo, Dentsply, Konstanz, D) zur Versorgung eines dentinanalogen Kompositstumpfes in Regio 46 mit Hilfe der CAD/CAM-Technologie (Cerec inLab SW 4.0, Bensheim, D) als Prüfkörper erstellt. Diese wurden in zwei Gruppen aufgeteilt. Eine Gruppe von 20 Kronen erhielt eine Politur, die andere Gruppe von 20 Kronen erhielt einen Glasurbrand (experimentell). Alle Prüfkörper wurden adhäsiv mit einem dualhärtendem Befestigungszement (RelyX Unicem, 3M ESPE, Seefeld, D) auf geschichteten Kompositstümpfen (Tetric EvoCeram, Ivoclar Vivadent, Schaan, FL) befestigt. Je die Hälfte der jeweiligen Gruppen (n=10) wurde einer 5-Jahres-Kausimulation unterzogen. Die Prüfkörper wurden mit 198 N im Kausimulator (Typ N6C41/N6W26 Willytec, München, D) belastet und es wurden 1,2 Mio. Kauzyklen durchgeführt. Es fand eine simultane thermische Wechselbelastung mit 5° C und 55° C temperiertem, destilliertem Wasser statt (Thermocyclinganlage Haake, Karlsruhe, D). Alle fehlerfreien und die unbelasteten Prüfkörper wurden in der Universalprüfmaschine (ZO10/TN2S, Zwick, Ulm, D) bis zum Bruch belastet und die Bruchlastwerte ermittelt. Mit Hilfe des Two-sample t-tests und einem Signifikanzniveau von p < 0,05 wurden die Werte verglichen. Alle polierten Prüfkörper überstanden die Kausimulation, während 80 % (n=8) der glasierten Prüfkörper frakturierten. Bei 50 % (n=5) der glasierten Prüfkörper entstanden Risse und bei 30 % (n=3) kam es zu Frakturen. Im Bruchbelastungstest wurde für die polierte Gruppe ohne Kaubelastung eine mittlere Bruchfestigkeit von 2245 N ± 340 N und nach Kaubelastung von 2861 N ± 931 N ermittelt. Die Werte weisen keinen statistisch signifikanten Unterschied auf. Für die glasierte Gruppe ohne Kaubelastung wurde eine mittlere Bruchfestigkeit von 2602 N ± 419 N und nach Kaubelastung von 3400 N ± 170 N festgestellt. Es muss jedoch darauf hingewiesen werden, dass nur noch zwei Prüfkörper nach Kausimulation in der Universalprüfmaschine getestet werden konnten und damit die Aussagekraft eingeschränkt ist. Den gemessenen Werten dieser Studie nach, hatte die Kausimulation mit simultaner thermischer Wechsellast keine erniedrigende Wirkung auf die Bruchfestigkeit der polierten Prüfkörper. Wahrscheinlich waren die experimentellen Brennparameter für die geringe Überlebensrate der glasierten Kronen verantwortlich. Die heute empfohlenen Brennparameter für den Glasurbrand haben eine 3-minütige Langzeitkühlung, die an den Brand anschließt.

Endodontic Access Effect on Full Contour Zirconia and Lithium Disilicate Failure Resistance

Article

Feb 2020

Objectives To evaluate the effect of endodontic access on the failure load resistance of both adhesively and conventionally luted, full-contour monolithic yttria-stabilized zirconium dioxide (Y-TZP) and adhesively luted lithium disilicate (LD) crowns cemented on prepared teeth. Methods and Materials Seventy-two human maxillary molars were prepared per respective guidelines for all-ceramic crowns with one group (n=24) restored with LD and the other (n=48) receiving Y-TZP crowns. Preparations were scanned using computer-aided design/computer-aided milling (CAD/CAM) technology, and milled crowns were sintered following manufacturer recommendations. All LD crowns and half (n=24) of the Y-TZP crowns were adhesively cemented, while the remaining Y-TZP specimens were luted using a conventional glass ionomer cement (GIC). One LD group, one Y-TZP adhesive group, and one GIC-luted group (all n=12) then received endodontic access preparations by a board-certified endodontist: the pulp chambers were restored with a dual-cure, two-step, self-etch adhesive and a dual-cure resin composite core material. The access preparations were restored using a nano-hybrid resin composite after appropriate ceramic margin surface preparation. After 24 hours, all specimens were loaded axially until failure; mean failure loads were analyzed using Mann-Whitney U test ( α=0.05) Results Endodontic access did not significantly reduce the failure load of adhesively luted LD or Y-TZP crowns, but Y-TZP crowns with GIC cementation demonstrated significantly less failure load. Conclusions These initial findings suggest that endodontic access preparation may not significantly affect failure load resistance of adhesively luted Y-TZP and LD crowns. Definitive recommendations cannot be proposed until fatigue testing and coronal seal evaluations have been accomplished.

Chipped porcelain-fused-to-metal restoration repaired by the novel self-glazed zirconia veneering with a digital workflow

Article

Jan 2020

In the clinical application of traditional porcelain-fused-to-metal crowns and bridges, porcelain chipping has appeared as the major problems encountered by dentists. Once fracture occurs, neither aesthetics nor chewing efficiency remains. It is difficult to meet clinical needs with current repairing options. Self-glazed zirconia has been developed recently and is widely used in crowns, bridges, and veneering owing to its high strength, low wear on opposite teeth, and aesthetic appeal. In this study, we explore the application prospect of the chipped porcelain-fused-to-metal restoration repaired by the novel self-glazed zirconia veneering with a digital workflow. The results demonstrated that self-glazed zirconia can meet both the aesthetical and functional requirements of anterior and molar teeth in a timely and efficient manner.

Effects of the Thickness Ratio of Zirconia–Lithium Disilicate Bilayered Ceramics on the Translucency and Flexural Strength

Article

Dec 2019

Purpose: To determine the effects of the total thickness and core/veneer thickness ratio of bilayered ceramics on their three-point flexural strength and translucency. Materials and methods: Two groups of specimens were prepared with two different total thicknesses, 1.0 mm and 0.6 mm, and these groups were divided into five and three subgroups with ten specimens each, respectively, having different core/veneer thickness ratios. Lithium disilicate was pressed on the zirconia surface using the "lost-wax technique." The translucency and three-point flexural strength were measured, and a one-way analysis of variance test (p < 0.05) was performed to determine whether the translucency and three-point flexural strength were affected by the total thickness and core/veneer thickness ratio of the specimens. Results: For the same total thickness, translucency decreased with a decrease in the zirconia core proportion (p < 0.001). For the same core/veneer ratio, the translucency decreased with an increase in the total thickness (p < 0.001). If the zirconia thickness was less than half of the total thickness, the bilayered ceramic specimens containing zirconia cores and monolithic lithium disilicate specimens exhibited the same translucency. The three-point flexural strength increased with the increasing proportion of zirconia; however, it did not change significantly with the total thickness. However, for the same total thickness, the flexural strengths of the bilayered ceramics were higher than those of the monolithic specimens. Conclusions: At the same total thickness, increasing the zirconia core thickness decreased the translucency and increased the three-point flexural strength. Bilayered ceramic specimens with low zirconia ratios exhibited translucency similar to that of monolithic lithium disilicate ceramic but a higher flexural strength. This article is protected by copyright. All rights reserved.

A 3-year follow-up study of all-ceramic single and multiple crowns performed in a private practice: A prospective case series

Article

Full-text available

Nov 2011

Zirconia-based prostheses are commonly used for aesthetic crown and fixed restorations, although follow-up data are limited, especially for implant-supported crowns. The aim of this study was to evaluate the three-year clinical results of the installation of 463 zirconia core crowns by a general dental private practice. This study followed 142 patients (69 men and 73 women; aged 28-82 years) who had received 248 single crowns (202 tooth-supported, 36 implant-supported) and 225 multiple units of up to six elements (81 tooth-supported, 144 implant-supported). Clinical events, including fracture and loss of retention, secondary caries, and marginal integrity, were recorded. The overall failure rate was computed for the fractured and lost prostheses. Aesthetic, functional, and biological properties were rated, and patient satisfaction was investigated. During the three-year follow-up period, four patients were lost from the study (18 crowns, 4% of the total crowns). Three of the zirconia prostheses suffered fractures in more than three units (11 crowns; one- vs. three-year follow-up, p<0.05, Wilcoxon signed-rank test), and the cumulative prosthesis survival rate was 98.2%. Twelve units lost retention and were re-cemented, and no secondary caries of the abutment teeth were reported. The aesthetic, functional, and biological properties were generally well-rated, and there were no differences between tooth- and implant-supported crowns. The lowest scores were given regarding the anatomical form of the crowns, as some minor chipping was reported. Relatively low scores were also given for the periodontal response and the adjacent mucosa. Overall, patient satisfaction was high. At the three-year follow-up, the zirconia-core crowns appeared to be an effective clinical solution as they had favorable aesthetic and functional properties. Only the marginal fit of the prostheses should be improved upon.

CAD/CAM Zirconia vs. slip-cast glass-infiltrated Alumina/Zirconia all-ceramic crowns: 2-Year results of a randomized controlled clinical trial

Article

Full-text available

Feb 2009

The aim of this randomized controlled clinical trial was to compare the early clinical outcome of slip-cast glass-infiltrated Alumina/Zirconia and CAD/CAM Zirconia all-ceramic crowns. A total of 30 InCeram Zirconia and Cercon Zirconia crowns were fabricated and cemented with a glass ionomer cement in 20 patients. At baseline, 6-month, 1-year, and 2-year recall appointments, Californian Dental Association (CDA) quality evaluation system was used to evaluate the prosthetic replacements, and plaque and gingival index scores were used to explore the periodontal outcome of the treatments. No clinical sign of marginal discoloration, persistent pain and secondary caries was detected in any of the restorations. All InCeram Zirconia crowns survived during the 2-year period, although one nonvital tooth experienced root fracture coupled with the fracture of the veneering porcelain of the restoration. One Cercon Zirconia restoration fractured and was replaced. According to the CDA criteria, marginal integrity was rated excellent for InCeram Zirconia (73%) and Cercon Zirconia (80%) restorations, respectively. Slight color mismatch rate was higher for InCeram Zirconia restorations (66%) than Cercon Zirconia (26%) restorations. Plaque and gingival index scores were mostly zero and almost constant over time. Time-dependent changes in plaque and gingival index scores within and between groups were statistically similar (p>0.05). This clinical study demonstrates that single-tooth InCeram Zirconia and Cercon Zirconia crowns have comparable early clinical outcome, both seem as acceptable treatment modalities, and most importantly, all-ceramic alumina crowns strengthened by 25% zirconia can sufficiently withstand functional load in the posterior zone.

Endodontic Complications Following Periodontal and Prosthetic Treatment of Patients With Advanced Periodontal Disease

Article

Full-text available

Mar 1984

A retrospective analysis was carried out to determine the frequency and onset of endodontic complications occurring in 52 patients treated for advanced periodontal disease. Comparisons were made between teeth which, following periodontal treatment, were used as abutments in fixed prosthetic reconstructions and nonabutment teeth. The study included 672 teeth with initially vital pulps (255 abutment teeth and 417 nonabutment teeth). The observation period varied from 4 to 13 years with a mean of 8.7 years. Pulpal necrosis including periapical lesions developed with a significantly higher frequency in abutment teeth than in nonabutment teeth (15% vs. 3%). The majority of these lesions did not appear until several years following the completion of active treatment. Conceivable reasons for the development of pulpal necrosis in teeth subjected to combined periodontal and prosthetic treatment are discussed.

An Overview of Zirconia Ceramics: Basic Properties and Clinical Applications

Article

Full-text available

Dec 2007
J DENT

Zirconia (ZrO2) is a ceramic material with adequate mechanical properties for manufacturing of medical devices. Zirconia stabilized with Y2O3 has the best properties for these applications. When a stress occurs on a ZrO2 surface, a crystalline modification opposes the propagation of cracks. Compression resistance of ZrO2 is about 2000 MPa. Orthopedic research led to this material being proposed for the manufacture of hip head prostheses. Prior to this, zirconia biocompatibility had been studied in vivo; no adverse responses were reported following the insertion of ZrO2 samples into bone or muscle. In vitro experimentation showed absence of mutations and good viability of cells cultured on this material. Zirconia cores for fixed partial dentures (FPD) on anterior and posterior teeth and on implants are now available. Clinical evaluation of abutments and periodontal tissue must be performed prior to their use. Zirconia opacity is very useful in adverse clinical situations, for example, for masking of dischromic abutment teeth. Radiopacity can aid evaluation during radiographic controls. Zirconia frameworks are realized by using computer-aided design/manufacturing (CAD/CAM) technology. Cementation of Zr-ceramic restorations can be performed with adhesive luting. Mechanical properties of zirconium oxide FPDs have proved superior to those of other metal-free restorations. Clinical evaluations, which have been ongoing for 3 years, indicate a good success rate for zirconia FPDs. Zirconia implant abutments can also be used to improve the aesthetic outcome of implant-supported rehabilitations. Newly proposed zirconia implants seem to have good biological and mechanical properties; further studies are needed to validate their application.

Complication rate of molar crowns: A practice-based clinical evaluation

Article

Jan 2011
Int J Comput Dent

This practice-based study evaluates the initial clinical performance of conventionally luted metal-ceramic and zirconia molar crowns fabricated with a prolonged cooling period of the veneering porcelain. Forty-nine patients were treated (group A: high precious alloy + low fusing porcelain; group B: zirconia crowns). All zirconia crowns were veneered with a modified porcelain firing cycle including a 6-minute cooling period. Ninety-two restorations (74 vital abutments/18 nonvital abutments) were evaluated after a mean observation period of 18.2 +/- 4.6 months. No complete failures or loss of vitality were recorded in either group. Two events were recorded in group A (1 loss of retention/1 minor ceramic chipping < 2 mm2). The third event occurred in group B (minor ceramic chipping <2 mm2). All ceramic defects could be polished intraorally. Statistical analysis revealed non-significant differences in success rates (p = 0.91) of metal-ceramic and zirconia crowns fabricated with a modified porcelain firing. The modified firing of the zirconia porcelain seems to decrease the risk for early ceramic chipping in the molar area, leading to a technical complication rate comparable to that of metal-ceramic crowns.

The Performance of Zirconium Dioxide Crowns: A Clinical Follow-up

Article

Sep 2010
INT J PROSTHODONT

Thirty-two patients who had been treated with 71 computer-aided design/computer-assisted manufacture-fabricated Cercon crowns were followed to assess clinical performance by time-to-event analysis. Clinical examinations consisted of a complete dental and oral hygiene examination and a quality assessment by modified California Dental Association criteria. Four patients (6 crowns) were lost to follow-up; another 11 crowns had to be excluded from evaluation for comparability reasons. Six of 54 evaluated crowns experienced complications (P(C) = 11.1%) throughout a mean observation time of 21 months. Survival was estimated at 0.98 over 24 months. The good overall clinical performance was affected predominantly by technical complications of the veneering ceramic (P(TC) = 9.3%).

Prospective study of zirconia-based restorations: 3-year clinical results

Article

Sep 2010

To evaluate fixed dental prostheses (FDPs) and single crowns made of zirconia substructures veneered with new fluorapatite veneering porcelain. Thirty-eight patients received 18 FDPs and 50 single crowns. Zirconia substructures were fabricated by a CAD/CAM system and veneered using the powder buildup technique. All restorations were cemented with glass ionomer. Baseline evaluation was performed 2 weeks after cementation with recall examinations at 12, 24, and 36 months by calibrated investigators. SEM was performed on replicas of all restorations. Survival probabilities according to Kaplan-Meier were calculated. The mean service time was 35 (+/- 14) months. After 3 years of clinical service, three biologic and five technical failures were recorded. All failures occurred in the FDP group. One FDP was removed after biologic failure of one abutment tooth. The Kaplan-Meier survival probability was 88.2% after 35 months for all types of failures and 98.5% concerning restorations in service. The type of restoration showed significant influence on the survival probability (P < .001, log-rank test). No influence on gingival parameters from the restorations was observed compared to control teeth. Zirconia substructures veneered with fluorapatite veneering porcelain seem to be a reliable treatment option. More research has to be conducted to investigate differences between single crowns and FDPs.

Clinical Trials in Zirconia: A Systematic Review

Article

Aug 2010
J ORAL REHABIL

Zirconia is unique in its polymorphic crystalline makeup, reported to be sensitive to manufacturing and handling processes, and there is debate about which processing method is least harmful to the final product. Currently, zirconia restorations are manufactured by either soft or hard-milling processes, with the manufacturer of each claiming advantages over the other. Chipping of the veneering porcelain is reported as a common problem and has been labelled as its main clinical setback. The objective of this systematic review is to report on the clinical success of zirconia-based restorations fabricated by both milling processes, in regard to framework fractures and veneering porcelain chipping. A comprehensive review of the literature was completed for in vivo trials on zirconia restorations in MEDLINE and PubMed between 1950 and 2009. A manual hand search of relevant dental journals was also completed. Seventeen clinical trials involving zirconia-based restorations were found, 13 were conducted on fixed partial dentures, two on single crowns and two on zirconia implant abutments, of which 11 were based on soft-milled zirconia and six on hard-milled zirconia. Chipping of the veneering porcelain was a common occurrence, and framework fracture was only observed in soft-milled zirconia. Based on the limited number of short-term in vivo studies, zirconia appears to be suitable for the fabrication of single crowns, and fixed partial dentures and implant abutments providing strict protocols during the manufacturing and delivery process are adhered to. Further long-term prospective studies are necessary to establish the best manufacturing process for zirconia-based restorations.

A 3-Year Retrospective and Clinical Follow-Up Study of Zirconia Single Crowns Performed in a Private Practice

Article

Jul 2009

All-ceramic crowns have become increasingly used also in the posterior regions, but there are only few studies documenting the clinical outcome of these restorations. The aim was therefore to present the 3-year outcome of zirconia (NobelProcera) single crowns. All patients treated with porcelain-veneered zirconia single crowns in a private practice during the period October 2004 to November 2005 were included. The patient records were scrutinized for data on the restorations and the supporting teeth. Information was available for 161 patients and 204 crowns. At the 3-year recall appointments, a sample of 18 patients with 25 crowns was clinically examined and interviewed regarding patient satisfaction. Most crowns (78%) were placed on premolars and molars. The clinical outcome of the crowns was favourable. No zirconia core fractured and no caries was observed on the abutment teeth. Some types of complication were recorded for 32 (16%) crowns or abutment teeth. The most severe complications, in total 12 restorations (6%), were recorded as failures: abutment tooth was extracted (5), remake of crown due to lost retention (4), veneer fracture (2) and persistent pain (1). The CDA criteria for 25 crowns were rated favourably, and patient satisfaction with the zirconia crowns was in general high. The porcelain-veneered zirconia crowns (NobelProcera) showed good clinical results, were well accepted by the patients, and only few complications were reported over the 3-year follow-up period.

Clinical Complications in Fixed Prosthodontics

Article

Aug 2003
J PROSTHET DENT

The purpose of this article is to identify the incidence of complications and the most common complications associated with single crowns, fixed partial dentures, all-ceramic crowns, resin-bonded prostheses, and posts and cores. A Medline and an extensive hand search were performed on English-language publications covering the last 50 years. The searches focused on publications that contained clinical data regarding success/failure/complications. Within each type of prosthesis, raw data were combined from multiple studies and mean values calculated to determine what trends were noted in the studies. The lowest incidence of clinical complications was associated with all-ceramic crowns (8%). Posts and cores (10%) and conventional single crowns (11%) had comparable clinical complications incidences. Resin-bonded prostheses (26%) and conventional fixed partial dentures (27%) were found to have comparable clinical complications incidences. The 3 most common complications encountered with all-ceramic crowns were crown fracture (7%), loss of retention (2%), and need for endodontic treatment (1%). The 3 most common complications associated with posts and cores were post loosening (5%), root fracture (3%), and caries (2%). With single crowns, the 3 most common complications were need for endodontic treatment (3%), porcelain veneer fracture (3%), and loss of retention (2%). When fixed partial denture studies were reviewed, the 3 most commonly reported complications were caries (18% of abutments), need for endodontic treatment (11% of abutments), and loss of retention (7% of prostheses). The 3 most common complications associated with resin-bonded prostheses were prosthesis debonding (21%), tooth discoloration (18%), and caries (7%).

A systematic review of the survival and complication rates of all-ceramic and metal-ceramic reconstructions after an observation period of at least 3 years. Part I: Single crowns

Article

Jul 2007

The objective of this systematic review was to assess the 5-year survival rates of all-ceramic single crowns and to compare it with the survival rates of metal-ceramic crowns and to describe the incidence of biological and technical complications. An electronic Medline and Dental Global Publication Research System search complemented by manual searching was conducted to identify prospective and retrospective cohort studies on all-ceramic and metal-ceramic crowns with a mean follow-up time of at least 3 years. Patients had to have been examined clinically at the follow-up visit. Assessment of the identified studies and data abstraction was performed independently by two reviewers. Annual failure rates were analyzed using standard and random-effects Poisson regression models to obtain summary estimates of survival proportions. The search provided 3473 titles and 177 abstracts. Full-text analysis was performed for 86 articles, resulting in 34 studies that met the inclusion criteria. In meta-analysis, the 5-year survival of all-ceramic crowns was estimated at 93.3% (95% confidence interval (CI): 91.1%-95%) and 95.6% (95% CI: 92.4%-97.5%) for metal-ceramic crowns. All-ceramic crowns were also analyzed according to the material utilized. Densely sintered alumina (Procera technique) crowns showed the highest 5-year survival rate of 96.4%, followed by reinforced glass-ceramic crowns (Empress technique) and InCeram-crowns with survival rates of 95.4% and 94.5%, respectively. A significantly lower survival rate of 87.5% was calculated for glass-ceramic crowns after 5 years. All-ceramic crowns were also grouped and analyzed regarding the position in the mouth. All four types of all-ceramic crowns showed lower survival rates when seated on posterior teeth. Moreover, for glass-ceramic crowns (84.4%) and InCeram-crowns (90.4%), this difference reached statistical significance (P = 0.009, P = 0.028). Based on the present systematic review, all-ceramic crowns, when used for anterior teeth, showed survival rates at 5 years comparable to those seen for metal-ceramic crowns. When used for posterior teeth, the survival rates at 5 years of densely sintered alumina crowns (94.9%) and reinforced glass-ceramic crowns (93.7%) were similar to those obtained for metal-ceramic crowns. Furthermore, lower survival rates of 90.4% and 84.4% can be expected for InCeram crowns and glass-ceramic crowns when utilized for premolars and molars.

What is the prevalence of various types of prosthetic dental restoration in Europe?

Article

Jul 2007

The aim of this review was to analyse the prevalence of prosthetic dental restorations in the adult population in Europe and to investigate factors influencing the frequencies of fixed restorations and removable dental prostheses (RDP). A search for literature up to 31 October 2006 on dental restorations was performed in Medline via PubMed and in an additional hand search using several keywords related to epidemiology and dental restorations. Out of approximately 6000 titles listed, 136 articles were identified, which were related to 13 different European countries. 43 articles fulfilled the inclusion criteria and were included in this review. Approximately half of the adult population in most European countries have had some type of prosthetic dental restoration. The frequency of RDPs among adults varied between 13 and 29%, with 3-13% edentulous subjects wearing complete dentures in both jaws. The frequency of fixed restorations including crowns and fixed dental prostheses (FDPs, bridges) was the highest in Sweden with 45% and Switzerland (34%). In the recent decades, there has been a slight decrease in RDP use reflecting a decline in edentulism, while more subjects had maintained a residual dentition and were wearing removable partial dentures or fixed restorations. The latter are less prevalent in countries with lower prosperity. If only a few teeth are absent, these are generally replaced with FDPs or have no replacement. If more teeth are missing, the likelihood of a removable restoration increases with the number of teeth to be replaced. A higher frequency of removable restorations is present in older age groups, in subjects living in rural areas, in those from a lower socio-economic status and in subjects with less education and lower incomes. All types of fixed and removable restorations are highly prevalent, especially among older age groups, in most European countries. There is a trend towards higher frequencies of fixed restorations, more removable partial dentures and a reduction in complete dentures.

Ten-Year Outcome of Crowns Placed within the General Dental Services in England and Wales

Article

Jun 2008
J DENT

It is the aim of this paper to consider the factors associated with the need for re-intervention on a crown, and the times to re-intervention. A data set was established consisting of patients, 18 years or older, whose birthdays were included within a set of a randomly selected dates, one of which was chosen in each possible year of birth and whose restoration records contained the placement of one or more indirect restorations on courses of treatment with last date on the claim form after 31st December 1990, and with date of acceptance after September 1990 and before January 2002. For each tooth treated with a crown, the subsequent history of intervention on that tooth was consulted, and the next date of intervention, if any could be found in the extended data set, was obtained. Thus, a data set was created of crowns which have been placed, with their dates of placement and their dates, if any, of re-intervention. Data for over 80,000 different adult patients were analysed, of whom 46% were male and 54% female. A total of 47,474 crown restoration occasions were obtained from the data over a period of 11 years. Metal crowns were found to have the longest survival-68% at 10 years, and all-porcelain crowns the shortest-48% at 10 years. Factors which were found to influence outcome of crowns included type of crown, age of patient, patient payment exemption status, patient attendance pattern and placement of a root filling in the same course of treatment as a crown. Full-coverage all-metal crowns have longer survival times before re-intervention than metal-ceramic crowns and all-ceramic crowns. Root fillings are associated with reduced survival time of the crowns examined in this study.

Prospective study of zirconia-based restorations: 3-year clinical results

Jan 2010
631-638

F Beuer
M Stimmelmayr
W Gernet
D Edelhoff
Jf Gü H
M Naumann

Beuer F, Stimmelmayr M, Gernet W, Edelhoff D, Gü h JF, Naumann M. Prospective study of zirconia-based restorations: 3-year clinical results. Quintessence International 2010;41:631-7.

A 5-year retrospective study of survival of zirconia single crowns fitted in a private clinical setting

Abstract

No full-text available

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