Alternative crown systems. Is the metal-ceramic crown always the restoration of choice?
The metal-ceramic crown system still is selected the most frequently because of its strength and versatility. The ability to select metals for color or strength for single units or fixed partial dentures gives great flexibility, but when esthetics of the anterior region are a prime concern, the all-ceramic crown is still an excellent choice. Choice of which all-ceramic system to use is dependent on the strength demands, esthetic needs, amount of tooth structure that can be preserved, and laboratory support available. Where good tooth structure remains but some color, contour, or incisal length changes are desired, the porcelain laminate veneer is an outstanding esthetic and restorative choice. When good labial tooth structure remains but lingual structure is inadequate, a partial veneer gold crown can be an excellent esthetic choice. If moderate tooth structure is lost or moderate staining is present, the Dicor crown is a superb choice. In those instances in which heavy staining is present, a foil or core system should be considered to completely block out the background colors. As the occlusal forces become more of a factor, selection of a restorative system will depend more on strength than esthetic demands. The aluminous porcelain jacket crown still offers great strength and esthetics at a reasonable price. When most of the color is on the surface of the teeth, or when there is a high translucency to the teeth, Dicor can provide very esthetic results, and the Dicor Plus crown offers the opportunity to develop intrinsic shading. When greater strength is required, selection of a foil and core system is suggested, as might be a system that provides a stronger core material, like Alceram or Inceram. These stronger core materials will render improved flexural and compressive strengths, but some increases in brightness may occur with the increased alumina content of the cores. The future in ceramic restorative dentistry may be in the computer-generated crown if ways to develop internal coloring and layered building can be developed and cost can be controlled. Ceramic crowns are best limited to the anterior region of the mouth where occlusal forces normally are less than those found in the posterior region. In selected cases, in which there is no evidence of parafunctional habits, and when the dentist and technician are well versed in functional occlusion and have maximum restorative control of the occlusion, posterior ceramic restorations will be successful. It is important to remember in these cases that porcelain is harder than enamel and very strong in compression.(ABSTRACT TRUNCATED AT 400 WORDS)
Wall
J G
JG
Department of Prosthodontics, Ohio State University, College of Dentistry, Columbus.
Cipra
D L
DL
D000537:Aluminum Oxide; D000538:Aluminum Silicates; D001672:Biocompatible Materials; D002516:Ceramics; D003442:Crowns; D003776:Dental Porcelain; D003801:Dental Veneers; D006047:Gold Alloys; D006801:Humans; D016876:Metal Ceramic Alloys; D012834:Silver; D013499:Surface Properties; D013813:Therapy, Computer-Assisted; D014025:Titanium
D000538:Aluminum Silicates; D001672:Biocompatible Materials; C047475:Dicor ceramic; D006047:Gold Alloys; C062269:Hi Ceram; C075815:IPS-Empress ceramic; D016876:Metal Ceramic Alloys; C077451:Procera; D003776:Dental Porcelain; C073101:Optec; C070870:In-Ceram; D012834:Silver; C077450:Sunrise alloy; C050798:cerestore; D014025:Titanium; D000537:Aluminum Oxide