| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1420797 | Dental Materials | 2015 | 8 Pages |
•We have tested the fatigue to contact loading of porcelain veneer on zirconia.•Results show apparition of cracking under cyclic loads in humid environments.•An estimation of lifetime of porcelain coatings under service is provided.•Protecting the dental ceramic by a guard could increase the lifetime of the materials.
ObjectivesTo understand the resistance to cyclic and static contact loading of feldspathic porcelain on dental zirconia (3Y-TZP), in order to understand the partial failure of porcelain (chipping or cracking).MethodsHertzian contact techniques were used to evaluate the appearance of damage as a ring crack in terms of applied load and number of cycles in air and simulated saliva.ResultsStatic contact loading showed the presence of stress corrosion cracking in the porcelain; the environmental crack growth in air was determined from the results of time to damage under static load. There was also a contribution of fatigue effects due to the interactions of the crack with the microstructure. From the obtained results, a time to failure was estimated depending on the material counterpart. Cracking can occur on porcelain coatings if the contact counterpart is teeth or porcelain in a time interval of a few years, consistent with clinical studies.SignificanceContact loading, particularly against teeth or other ceramic materials can be a significant cause of failure and chipping of feldspathic porcelain on zirconia, especially if the patient suffers from bruxism. Protection, by e.g. a guard, against repetitive contact against the porcelain can increase the lifetime of the veneer.
