Crown Removers: A Review

The Journal of Prosthetic Dentistry, 2010

The clinical behavior of newly developed ceramic systems used for posterior restorations is relatively unknown. The preliminary results of this prospective clinical study support the use of the IPS e.max Press ceramic and Procera AllCeram crowns for the restoration of posterior teeth.

Prague medical report, 2013

The objective of the study was to evaluate the clinical outcomes of all-ceramic crowns three years after placement of the restoration in the oral cavity. The aim of the present clinical study were surveyed the Procera ® , Cercon ® and LAVA™ systems. In total, 121 crowns were followed in 33 patients (7 men and 26 women) with an average age of 53.5 years. The eighty crowns were placed in anterior and forty one crowns in posterior teeth. The crowns were fabricated in two dental laboratories and delivered in two private dental practices. The clinical trial was conducted according to American Dental Association guidelines. The patients were requested to provide their consent to the regular clinical examination including radiographic and photographic records. A total of 102 crowns were made of zirconium oxide ceramic cores-58 Cercon ® ; 43 LAVA™, while 19 crowns were made of aluminum oxide cores Procera ®. The veneering ceramic LAVA™ Ceram was used. The success rate was analyzed using Kaplan-Meier statistics and, in our case, the overall three-year success rate reached 96.7%. All-ceramic crowns with polycrystalline ceramic cores have low susceptibility to fracture, in this study just 3.3%. This study was supported by grants IGA NS /9744-3 and IGA MZCR 13351-4 Czech Republic.

Journal of Prosthetic Dentistry, 2000

Stomatology Edu Journal

Background: Partial ceramic crowns (PCCs) are more tooth conservative and potentially less stressful for the periodontium than full coverage crowns and meet the esthetic demands of patients. Objective: evidence shall be provided, if PCCs are a reliable treatment option, and under which conditions. Data sources: this review is based on own published data and experiences and on a review of the literature. Results: Longevity of PCCs is in the range of partial crowns from gold alloys. Failures due to chip fractures, bulk fractures, or debonding can be avoided/reduced by proper technique. Most clinical experience exists with leucite reinforced silicate or lithium disilicate ceramics, either pressed or CAD/CAM processed. Tooth preparation must respect the need for sufficient ceramic thickness of at least 1.5 mm. Residual buccal or oral cusps of less than 2 mm thickness should be included in the preparation. Cavity preparation should be defect oriented with few parallel walls as guidance for placement. Dual curing luting composites together with etch and rinse (E&R) adhesives are standard. Self-adhesive materials can be used but are sensitive to tooth desiccation before luting. Clinical experience with new universal adhesives is limited, but available results are promising. Light curing should be performed by applying 32 J/cm 2 from oral, buccal and occlusal aspects (silicate based ceramics). Conclusions: PCCs are a reliable treatment option for extended defects in posterior teeth. Special guidelines must be followed including sufficient ceramic thickness and proper adhesive technique to avoid failures.

Stomatoloski glasnik Srbije, 2008

The International Journal of Prosthodontics

To assess and compare the clinical outcomes of three different types of all-ceramic posterior monolithic tooth-supported crowns. Materials and Methods: A total of 71 patients received 90 all-ceramic crowns randomized to be either high-translucency zirconia (ZC), high-translucency zirconia with a partial buccal veneer (ZC-V), or lithium disilicate glassceramic (LDS). All treatments were performed by four general dentists. Choice of material was blinded. Baseline and subsequent annual evaluation were based on modified California Dental Association (CDA) criteria. A questionnaire was used to include patient-reported outcomes and to compare them to the crown quality rating performed by dentists. Results: A total of 66 patients with 84 crowns were examined after 3 years. The survival rate was 98.8%. No crowns fractured during the observation period. One ZC-V crown failed due to loss of retention, and three complications were noted: loss of retention occurred in one ZC crown, and two ZC crowns needed to be endodontically treated. There was no significant difference between the different crowns regarding marginal integrity, surface, or anatomical form. Both patients and examining dentists rated the crowns favorably regarding esthetics, patients more than dentists. Conclusion: Posterior lithium disilicate glass-ceramic crowns and translucent zirconia crowns with or without a partial buccal veneer show excellent and promising clinical outcomes from a short-term perspective. Patients and dentists rate the restorations favorably concerning esthetics and function.

Different ceramics are available for monolithic crowns, including lithium disilicate, 1 zirconia, 2 lithium silicate, and polymer-infiltrated ceramics. 3 Polymer-infiltrated ceramics, marketed as Vita Enamic (Vita Zahnfabrik), was introduced in 2013 as a hybrid ceramic with the claim that it had improved mechanical properties, combining resistance, 4 esthetics, 5 and lower risk of failure. 6 Polymer-infiltrated ceramics are composed of an inorganic matrix of feldspathic ceramic (86% by weight) that is, infiltrated by resin (14% by weight). 4,5 This combination provides high flexural strength of 150 to 160 MPa, esthetics, and good tolerance to damage because the interconnected Supported by the Coordination for the Improvement of Higher Education Personnel-Brazil (CAPES)-Financing Code 001.

Journal of Applied Oral Science, 2004

ll ceramic crowns are highly esthetic restorations and their popularity has risen with the demand for lifelike and cosmetic dentistry. Recent ceramic research has concentrated on developing a fundamental understanding of ceramic damage modes as influenced by microstructure. Dental investigations have elucidated three damage modes for ceramic layers in the 0.5-2 mm thickness using point contacts that duplicate tooth cuspal radii; classic Hertzian cone cracking, yield (pseudo-plastic behavior), and flexural cracking. Constitutive equations based upon materials properties have been developed that predict the damage modes operational for a given ceramic and thickness. Ceramic thickness or thickness of the stiff supporting core in layer crowns is critical in flexural cracking as well as the flaw state of the inner aspect of the crown. The elastic module of the supporting structure and of the luting cement and its thickness play a role in flexural fracture. Clinical studies of ceramics extending over 16 years are compared to the above relationships and predictions. Recommendations for clinical practice are made based upon the above.

Prague medical report

The purpose of this study was to compare full metal crowns with two different types of veneering material -ceramics and polymer after a two-year period in a function. The aim was to evaluate the changes of occlusal relief, marginal adaptation, break of material, changes of shape and color and gingival status. One hundred and two crowns were examined in 34 patients immediately after cementation, and they were reviewed within two years of crown placement. These fixed restorations were checked according two modified US Public Health Service System criteria. After two years the crowns were found clinically intact in 94 % for metal-ceramics versus 98 % for metal-polymer. No crown was lost. There were found significant differences in positions of a crown margin between both materials and marginal adaptation between initial (baseline) and follow-up results. Gingival health at baseline was related in optimal in 67 % versus 77 %, after two years in 43 % versus 71 %. Slight mismatch in color occurred in 0 versus 60 % crowns, obvious mismatch was apparent in 0 versus 21 % crowns after two years. Within the limitations of this study, it was found that the examined metal crowns with two different veneerings are very stable fixed restorations, mechanical resistance and integrity of polymer material was surprisingly good but its color stability presented mismatch after two-years period. Ceramic veneering was excellent in color match but there were three visible cracks of the ceramic layer.

Journal of Esthetic and Restorative Dentistry, 2001

The functional and esthetic restoration of severely compromised anterior teeth is a challenge to clinicians in their daily practice. The duplication of the optical characteristics of an intact tooth, including shade, translucency, and fluorescence, is often made difficult by the use of metal infrastructures, such as post-and-cores and copings. The development of reinforced ceramics and nonmetallic post systems made possible the generation of metal-free ceramic restorations in severely compromised anterior and posterior teeth. This article discusses one available technique for the generation of a single all-ceramic restoration involving the use of a zirconia-or leucite-reinforced post-and-core system and of an all-ceramic crown system. A representative clinical case is presented illustrating the potential of the technique. 0 2 0 0 1 BC Decker Inc