title: Influence of abutment substrate and ceramic thickness on the colour of heat-pressed ceramic crowns.
abstract: All-ceramic crowns made of leucite-based heat-pressed ceramics are widely used to restore non-vital teeth in conjunction with various post and core materials. However, as some light passes through the ceramic, the colour of the abutment substrate can negatively affect the final aesthetic appearance of the all-ceramic crown. In this study, we made background specimens simulating gold-alloy cast posts and other simulating porcelain veneered cast posts, overlaid different thickness of heat-pressed ceramic on these background specimens, and measured the shifts in colour. We found that, when the background specimen was a gold alloy, the background colour had an effect on the apparent colour, unless the ceramic was more than 1.6 mm thick. When the background specimen was porcelain veneered, the background colour had no evident effect, even when the ceramic was not very thick. Therefore, when making a restoration using a leucite-based heat-pressed ceramic crown, it is advisable to use tooth-coloured materials such as a porcelain veneered cast post, if you will not be able to make the ceramic more than 1.6 mm thick.
mesh_terms: D000537:Aluminum Oxide; D000538:Aluminum Silicates; D003118:Color Perception; D003442:Crowns; D000044:Dental Abutments; D003776:Dental Porcelain / Q000737:chemistry; D017267:Dental Prosthesis Design; D006047:Gold Alloys; D006358:Hot Temperature; D016876:Metal Ceramic Alloys; D011176:Post and Core Technique; D017797:Prosthesis Coloring
chemical_list: D000538:Aluminum Silicates; D006047:Gold Alloys; C075815:IPS-Empress ceramic; D016876:Metal Ceramic Alloys; D003776:Dental Porcelain; C078519:leucite; D000537:Aluminum Oxide