Molar Metal Ceramic Crown Preparation

Metal ceramic crown preparation 2.

Molar metal ceramic crown preparation. The metal should be 0 3 to 0 5 mm thick if it is a noble metal alloy while a metal coping made of the more rigid base metal alloys can be thinner to 0 2 mm. Ensuring the preparation has a 90 cavosurface angle helps to prevent unfavourable distribution of stresses and minimises the risk of the crown fracturing. Complete coverage by metal. Porcelain fused to metal pfm crowns are among the most popular and reliable restorations because of its durability and natural esthetics using a cast metal substructure that is veneered with porcelain this material closely mimics the appearance of a natural tooth.

Metal ceramic porcelain fused to metal 2 0 mm incisally 0 5 1 0 mm lingual aspect porcelain guidance requires greater clearance 1 5 mm labial shoulder or heavy chamfer 0 5 mm lingual chamfer 1 5 mm circumferentially for 360 degree ceramic margin. The extent of the veneer can vary. To be successful a metal ceramic crown preparation requires considerable tooth reduction wherever the metal substructure is to be veneered with dental porcelain. Because there is no metal to block light transmission they can resemble natural tooth structure better in terms of color and translucency than can any other restorative option.

The preparation must be designed to provide the correct support for the porcelain along its entire incisal edge unless an all ceramic crown with a strong core i e. Most widely used. Full contour crowns metal or zirconia 1 0 mm non functional cusps 1 5 mm. To be successful a metal ceramic crown preparation requires more tooth reduction wherever the metal substructure is to be veneered with dental porcelain.

Only with sufficient thickness can the darker color of the metal substructure be masked and the veneer duplicate the appearance of a natural tooth. However sometimes the metal underlying the crown s porcelain can show through as a dark line especially. 11 tooth preparation for all ceramic restorations all ceramic inlays onlays veneers and crowns are some of the most esthetically pleasing prosthodontic restorations. To be successful a metal ceramic crown preparation requires considerable tooth reduction wherever the metal substructure is to be veneered with dental porcelain.

The extent of the veneer can vary. Veneer porcelain mimics 3 extention varies natural teethnatural teeth 4.