Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/329955
Type: Artigo
Title: Fracture Load And Phase Transformation Of Monolithic Zirconia Crowns Submitted To Different Aging Protocols
Author: Bergamo
E. T. P.; da Silva
W. J.; Cesar
P. F.; Del Bel Cury
A. A.
Abstract: Monolithic zirconia crowns have many favorable properties and may potentially be used to solve dental problems such as chipping. However, monolithic zirconia crown resistance can be affected by its phase transformation when subjected to low temperatures, humidity, and stress. This study evaluated the fracture load and phase transformation of monolithic zirconia crowns submitted to different thermal and mechanical aging tests. Seventy monolithic zirconia crowns were randomly divided into the following five groups: control, no treatment; hydrothermal aging at 1228 degrees C, two bar for one hour; thermal fatigue, 10(4) cycles between 58 degrees C and 558 degrees C, dwell time, 30 seconds; and mechanical fatigue, 10(6) cycles with a load of 70 N, sliding of 1.5 mm at 1.4 Hz; and combination of mechanical plus thermal fatigue. Fracture load was measured with a universal testing machine. Surface changes and fracture mode and origin were examined with a scanning electron microscope. Monoclinic phase content was evaluated by x-ray diffraction. The fracture load was analyzed using one-way analysis of variance at a level of 5%, and Weibull distribution was performed. No statistically significant differences were observed in the mean fracture load and characteristic fracture load among the groups (p>0.05). The Weibull modulus ranged from 6.2 to 16.6. The failure mode was similar for all groups with the crack origin located at the contact point of the indenter. Phase transformation was shown at different surfaces of the crown in all groups (1.9% to 8.9%). In conclusion, monolithic zirconia crowns possess high fracture load, structural reliability, and low phase transformation.
Subject: All-ceramic Crowns
Y-tzp
In-vitro
Mechanical-properties
Bearing Capacity
Dental Bridges
Single Crowns
Degradation
Fatigue
Translucent
Editor: Operative Dentistry INC
Indianapolis
Rights: fechado
Identifier DOI: 10.2341/15-154-L
Address: http://www.jopdentonline.org/doi/abs/10.2341/15-154-L
Date Issue: 2016
Appears in Collections:Unicamp - Artigos e Outros Documentos

Files in This Item:
File SizeFormat 
000386153800011.pdf1.97 MBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.