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Step-stress analysis for predicting dental ceramic reliability
- Source :
- Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual), Universidade de São Paulo (USP), instacron:USP
- Publication Year :
- 2013
- Publisher :
- Elsevier BV, 2013.
-
Abstract
- To test the hypothesis that step-stress analysis is effective to predict the reliability of an alumina-based dental ceramic (VITA In-Ceram AL blocks) subjected to a mechanical aging test.Bar-shaped ceramic specimens were fabricated, polished to 1μm finish and divided into 3 groups (n=10): (1) step-stress accelerating test; (2) flexural strength-control; (3) flexural strength-mechanical aging. Specimens from group 1 were tested in an electromagnetic actuator (MTS Evolution) using a three-point flexure fixture (frequency: 2Hz; R=0.1) in 37°C water bath. Each specimen was subjected to an individual stress profile, and the number of cycles to failure was recorded. A cumulative damage model with an inverse power law lifetime-stress relation and Weibull lifetime distribution were used to fit the fatigue data. The data were used to predict the stress level and number of cycles for mechanical aging (group 3). Groups 2 and 3 were tested for three-point flexural strength (σ) in a universal testing machine with 1.0MPa/s stress rate, in 37°C water. Data were statistically analyzed using Mann-Whitney Rank Sum test.Step-stress data analysis showed that the profile most likely to weaken the specimens without causing fracture during aging (95% CI: 0-14% failures) was: 80MPa stress amplitude and 10(5) cycles. The median σ values (MPa) for groups 2 (493±54) and 3 (423±103) were statistically different (p=0.009).The aging profile determined by step-stress analysis was effective to reduce alumina ceramic strength as predicted by the reliability estimate, confirming the study hypothesis.
- Subjects :
- Dental Stress Analysis
Time Factors
Materials science
Surface Properties
Dentistry
Materials testing
Article
Bite Force
Dental porcelain
Materials Testing
Dental polishing
Humans
General Materials Science
Step stress
Ceramic
Composite material
Pliability
General Dentistry
Reliability (statistics)
FADIGA DOS MATERIAIS
business.industry
Temperature
Reproducibility of Results
Water
Aging test
Dental Porcelain
Dental Polishing
Mechanics of Materials
visual_art
Microscopy, Electron, Scanning
visual_art.visual_art_medium
Stress, Mechanical
business
Algorithms
Forecasting
Subjects
Details
- ISSN :
- 01095641
- Volume :
- 29
- Database :
- OpenAIRE
- Journal :
- Dental Materials
- Accession number :
- edsair.doi.dedup.....64eaa47ee612ed17adc678fb2773364d