In Vivo Wear of All-ceramic and Metal-ceramic Crowns and Their Enamel Antagonists After Three Years
This study aims determine the wear rates of enamel versus enamel and enamel versus ceramic in human beings in relation to the microstructure of the ceramic material. Specific aims of the study and hypotheses are the following:
1. To characterize the microstructure (fracture toughness, particle size of ceramic, and inter-particle spacing) of three ceramic materials
2. To test the hypothesis that lower fracture toughness of glass and/or crystal phase in ceramics reduce wear damage of enamel.
3. To test the hypothesis that smaller sized crystals reduce wear damage of enamel.
4. To test the hypothesis that larger inter-particle spacing reduces wear damage of enamel.
5. To test the hypothesis that equivalent wear patterns exist in all directions between enamel versus enamel and ceramic versus enamel.
6. To test the hypothesis that bite force does not correlate with wear rates.
7. To test the hypothesis that salivary flow does not correlate with wear rates.
8. To test the hypothesis that a greater amount of wear is not associated with a loss in vertical dimension of occlusion.
9. To test the hypothesis that a greater amount of wear does not correlate with secondary cementum deposition as part of the passive eruption process.
10. To test the hypothesis that maximum wear occurs early and wear rates level off within the first two years.
11. To test the hypothesis that in vitro wear analysis does not correlate with in vivo wear measurements
Intervention Model: Single Group Assignment, Primary Purpose: Treatment
Wear of Enamel and Ceramic Over a Period of Three Years
University of Texas Health Science Center at San Antonio
University of Florida
Results (where available)
- Source: http://clinicaltrials.gov/show/NCT01128231
- Information obtained from ClinicalTrials.gov on July 15, 2010
Medical and Biotech [MESH] Definitions
A type of porcelain used in dental restorations, either jacket crowns or inlays, artificial teeth, or metal-ceramic crowns. It is essentially a mixture of particles of feldspar and quartz, the feldspar melting first and providing a glass matrix for the quartz. Dental porcelain is produced by mixing ceramic powder (a mixture of quartz, kaolin, pigments, opacifiers, a suitable flux, and other substances) with distilled water. (From Jablonski's Dictionary of Dentistry, 1992)
An implant used to replace one or more of the ear ossicles. They are usually made of plastic, Gelfoam, ceramic, or stainless steel.
Dental Restoration Wear
Occlusal wear of the surfaces of restorations and surface wear of dentures.
Epithelial cells surrounding the dental papilla and differentiated into three layers: the inner enamel epithelium, consisting of ameloblasts which eventually form the enamel, and the enamel pulp and external enamel epithelium, both of which atrophy and disappear before and upon eruption of the tooth, respectively.
Metal Ceramic Alloys
The fusion of ceramics (porcelain) to an alloy of two or more metals for use in restorative and prosthodontic dentistry. Examples of metal alloys employed include cobalt-chromium, gold-palladium, gold-platinum-palladium, and nickel-based alloys.
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