Document Detail


Cyclic fatigue resistance of ProTaper Universal instruments when subjected to static and dynamic tests.
MedLine Citation:
PMID:  20727501     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVE: This study evaluated the number of cycles to fracture of ProTaper Universal S2 instruments when subjected to static and dynamic cyclic fatigue tests.
STUDY DESIGN: ProTaper Universal S2 instruments were used until fracture in an artificial curved canal under rotational speed of 300 rpm in either a static or a dynamic test model. Afterward, the length of the fractured segments was measured and fractured surfaces and helical shafts analyzed by scanning electron microscopy (SEM).
RESULTS: The number of cycles to fracture was significantly increased when instruments were tested in the dynamic model (P<.001). Instrument separation occurred at the point of maximum flexure within the artificial canals, i.e., the midpoint of the curved canal segment. SEM analysis revealed that fractured surfaces exhibited characteristics of the ductile mode. Plastic deformation was not observed in the helical shaft of fractured instruments.
CONCLUSIONS: The number of cycles to fracture ProTaper Universal S2 instruments significantly increased with the use of instruments in a dynamic cyclic fatigue test compared with a static model. These findings reinforce the need for performing continuous pecking motions during rotary instrumentation of curved root canals.
Authors:
Hélio P Lopes; Izabelle M O Britto; Carlos N Elias; Julio C Machado de Oliveira; Mônica A S Neves; Edson J L Moreira; José F Siqueira
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics     Volume:  110     ISSN:  1528-395X     ISO Abbreviation:  Oral Surg Oral Med Oral Pathol Oral Radiol Endod     Publication Date:  2010 Sep 
Date Detail:
Created Date:  2010-08-23     Completed Date:  2011-01-05     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9508562     Medline TA:  Oral Surg Oral Med Oral Pathol Oral Radiol Endod     Country:  United States    
Other Details:
Languages:  eng     Pagination:  401-4     Citation Subset:  D; IM    
Copyright Information:
Copyright (c) 2010 Mosby, Inc. All rights reserved.
Affiliation:
Department of Endodontics, Faculty of Dentistry, Estácio de Sá University, Rio de Janeiro, Brazil.
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MeSH Terms
Descriptor/Qualifier:
Dental Alloys
Dental High-Speed Equipment*
Dental Instruments*
Dental Stress Analysis*
Elastic Modulus
Equipment Failure*
Humans
Materials Testing
Root Canal Preparation / instrumentation*
Chemical
Reg. No./Substance:
0/Dental Alloys

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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