The idea of use ceramic margins for metal-ceramic crowns was founded to
overcome problem of grayness for gingival margins that caused by metal collar in metal-ceramic crowns ,
but at the same time there are a lot of cautions on decrease mechanical
resistance for these restorations.
This study aims to study fracture resistance of metal-ceramic crowns with ceramic margins in 1 or 2 mm.
long, and compare it with mechanical resistance of metal-ceramic crowns with metal collar.
