 |
 |
 KEN MALAMENT
Dental ceramics, does it have to be a chip off the old block? |
|
All-ceramic materials were developed to improve ceramic color and marginal fi t. Until recently few research reports attempted to study their long term use or factors that relate to their performance without modeling the data. Present bi-layered all-ceramic crowns on molars have reached their full potential. Despite substantial improvements in material strength and toughness, they still fail because of breakage and chipping at relatively high rates. The Lithium Disilicate E Max mono-layered all-ceramic material is likely to change dentistry and the expectation for long-term ceramic survival. Ultimately crown performance is a complex set of interactions between crown material and geometry, the characteristics of the support structure of the cement and crown, and the clinical loading history. This presentation will provide a comprehensive look at failure modes and effects in bilayer all-ceramic crown-cement-tooth systems, tying together the infl uences on resistance to fracture initiation and propagation of ceramic material properties and thickness; crown/tooth geometry; cement modulus and layer thickness; damage induced by shaping, fabrication, clinical adjustments, and sandblasting; and fatigue in the wet intraoral environment. Original research will be presented that studied the clinical behavior of over four thousand all-ceramic restorations. Life history and fracture rates were studied over twenty years in relationship to factors that might affect success. Factors such as tooth position, preparation, luting procedures and gender are signifi cant to long term ceramic success. |
|
| Copyright © 2012 Quintessence Publishing Group Berlin |