Fatigue methods for evaluating translucent dental zirconia

Abstract

Objective: To investigate fatigue methods for the evaluation of translucent zirconia and to associate in vitro failures with clinically reported ones.

Data: Studies published in English that used fatigue tests on dental translucent zirconia.

Sources: Two databases (MEDLINE/PubMed and Scopus) were electronically searched without any restriction on year of publication.

Study selection: A total of 4555 studies were identified. After removal of duplicates (78) and irrelevant articles (4316) that did not meet the inclusion criteria, 161 articles were considered eligible based on their titles and abstracts. These articles were fully read, leading to the inclusion of 41 studies in the review.

Results: The most widely used fatigue method for evaluation of translucent zirconia was step-stress (18 articles), followed by staircase (seven articles), and step-wise (two articles). Most studies had been conducted in a wet environment with the use of a stainless steel piston to apply load to cemented structures on a dentin-like substrate. Most fracture analyses indicated the fracture originated on the cementation or contact surface where the load was applied. Moreover, studies that utilized anatomical structures (dental crowns) reported fractures starting at the cervical margin of the crowns.

Conclusion: Most studies used the step-stress method. Only three studies reported failures similar to those found in clinical trials that used translucent zirconia restorations.

Clinical significance: The study findings can assist on correlating clinical failures to the ones observed in vitro.

Keywords: Dental materials; Dentistry; Fatigue; Translucent zirconia.