Do Full contoured Zirconium crowns cause more wear than traditional pfms?

Picture provided by CreoDent laboratory

Probably not at least according to a recently randomized clinical study"Randomized clinical study of wear of enamel antagonists against polished monolithic zirconia crowns" published this year in the Journal of Dentistry(January 2018). The authors concluded that wear caused by all Zirconium crowns was comparable with porcelain fused to metal crowns. They believe that the final finish of the occlusal surface had more to do with the degree of wear than which type of crown was used.

This makes sense, since the occlusion and the smooth surface of the the articulating surface of a crown has a lot to do with the wear caused by a crown. Ideally posterior crowns should have a good contact when a patients mouth is closed but should not be in occlusion during all excursions. This type of occlusal scheme will minimize wear and breakage of either the crown or the tooth opposing.

It is clear that polishing any occlusal adjustment using diamond impregnated polishing wheels or other shaped bullets is important to minimize wear, since they tend to eliminate friction between the arches that might increase the amount of wear a patient experiences.

I hope this turns out to be the case , long term in Vivo, since full contoured all Zirconium crowns are becoming more popular with dentists. They are generated and designed using computers and when care is taken with the tooth's preparation and impressioning they seem like a viable alternative to classic PFM crowns.

I have been using these restorations for some of my patients and although the preparation is a little more exacting than a preparation for a pfm crown, the impressioning , fitting and cementation has been simpler and the laboratory bill is more affordable. My lab, CreoDent, offers two types of full contoured zirconium crowns one that is more opaque (stronger) and one that is quite translucent (less strong). To my eyes both provide acceptable esthetics but the translucent version has better esthetics especially when the stump shade allows its use. The opaque version may need additional staining to achieve optimal esthetics.

from Ask Dr. Spindel - http://lspindelnycdds.blogspot.com/2018/12/do-full-contoured-zirconium-crowns.html - http://lspindelnycdds.blogspot.com/

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