fracture origins in ceramic restorations: understanding the causes of failure
The fracture of a ceramic restoration always starts from one of the existing flaws in the material. A crack will propagate catastrophically when the maximum stresses generated by the patient are combined with defects that are created at different stages of the prosthesis production. Impurities added during manufacturing of CAD-CAM blocks at the industrial level, bubbles left by the dental technician, diamond bur damage created by the clinician and wear damage originated during patient mastication are examples of possible fracture origins that have already been identified by the science of dental fractography. The objective of this keynote lecture is to explain the basic underlying mechanism responsible for the fracture of ceramic restorations and depict all fracture origins that have already been identified by means of fractographic examination of broken pieces retrieved from dental practices. The final goal is to create an awareness regarding the main sources of failures in ceramic restorations, just so the responsible professional (industry, clinician or dental technician) can take action and ultimately increase the durability of all-ceramic prostheses.