Investigation of human dental crown applications in terms of fracture mechanics

At the present day, the dental crowns widely used in dentistry, consist of two different base components; subsupporting material and aesthetic veneering material. Although subsupporting materials are manufactured from metal or ceramic, veneers are only made from ceramics. Because of the problems in production stages, cracks can be formed in material interfaces. These cracks can propagate in time with mastication forces after treatment. And then fracture of the dental crown occurs, so the crown will become unusable.In this study, the critical J-integral value (JIC) of subsupport Ni-Cr alloy and dental porcelain interface, which are used in dental crowns, has been obtained. For this purpose, firstly, specimens have been manufactured which have sharp cracks in Ni-Cr/porcelain interface. Fracture loads of the specimens have been acquired from four point bend tests. Specimens have been modeled in finite element analysis software ABAQUS, the experimentally determined fracture loads have been applied and critical J-integral (JIC) values have been calculated.