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Comparative evaluation of cyclic fatigue resistance of D‐RaCe and ProTaper retreatment instruments in curved artificial canals
Author(s) -
Topçuoğlu H. S.,
Topçuoğlu G.,
Aktı A.
Publication year - 2016
Publication title -
international endodontic journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.988
H-Index - 119
eISSN - 1365-2591
pISSN - 0143-2885
DOI - 10.1111/iej.12488
Subject(s) - nickel titanium , cyclic stress , curvature , fracture (geology) , materials science , significant difference , root canal , dentistry , orthodontics , mathematics , composite material , geometry , medicine , shape memory alloy , statistics
Abstract Aim To compare the cyclic fatigue resistance of D‐RaCe and ProTaper rotary nickel–titanium (NiTi) retreatment files when used in curved artificial canals. Methodology A total of 120 new D‐RaCe DR 2 and ProTaper D3 retreatment files were tested in stainless steel artificial canals having 45° and 60° angles of curvature. Thirty instruments of each of the file systems were tested in both angles of curvature ( n = 30). The retreatment instruments were rotated until fracture to calculate the number of cycles to failure. The length of each fractured fragment was recorded. Data were analysed by independent sample t‐ test. Fractured surfaces of the instruments were analysed by scanning electron microscopy. Results In the canal with 45° angle of curvature, no significant difference was observed between the retreatment systems ( P > 0.05); on the other hand, in the canal with 60° angle of curvature, D‐RaCe DR 2 instruments had greater cyclic fatigue resistance than ProTaper D3 ( P < 0.05). No difference was observed between the retreatment instruments regarding the lengths of fractured fragments ( P > 0.05). The fracture surfaces of the instruments had morphologic characteristics of ductile fracture. Conclusions D‐RaCe DR 2 instrument exhibited greater cyclic fatigue resistance than ProTaper D3 only in root canals with 60° angle of curvature.