Predicting in vivo failure of rotary nickel-titanium endodontic instruments under cyclic fatigue
| Autor: | Ljubomir Petrovic, Milan Drobac, Teodor M. Atanackovic, Igor Stojanac |
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| Rok vydání: | 2012 |
| Předmět: |
Dental Stress Analysis
Dental Instruments Cyclic stress Materials science Rotation Mathematical relation Curvature Stress (mechanics) Nickel Humans Dental Restoration Failure General Dentistry Titanium Dental High-Speed Technique business.industry Equipment Design Structural engineering Models Theoretical Dental instruments Nickel titanium Ceramics and Composites Dental Pulp Cavity Deformation (engineering) business Root Canal Preparation Forecasting |
| Zdroj: | Dental Materials Journal. 31:650-655 |
| ISSN: | 1881-1361 0287-4547 |
| Popis: | The aim of this study was to examine the lifespan or number of cycles to failure of tapered rotary nickel-titanium (Ni-Ti) endodontic instruments. Simulated root canals with different curvatures were used to determine a relation between canal curvature and instrument lifespan. Using a novel mathematical model for the deformation of pseudoelastic Ni-Ti alloy, it was shown that maximum stress need not necessarily occur at the outer layer. On the basis of this observation, the Coffin-Manson relation was modified with parameters determined from this experiment. Results showed that the number of cycles to failure was influenced by the angle and radius of canal curvature and the size of instrument at the beginning of canal curvature. The resulting quantitative mathematical relation could be used to predict the lifespan of rotary Ni-Ti endodontic instruments under clinical conditions and thereby reduce the incidence of instrument failure in vivo. |
| Databáze: | OpenAIRE |
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