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Comparison of preparation of curved root canals with H yflex CM and R evo‐ S rotary nickel–titanium instruments
Author(s) -
Bürklein S.,
Börjes L.,
Schäfer E.
Publication year - 2014
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.12171
Subject(s) - nickel titanium , instrumentation (computer programming) , root canal , curvature , dentistry , orthodontics , radius of curvature , materials science , mathematics , significant difference , geometry , composite material , medicine , computer science , mean curvature , statistics , shape memory alloy , operating system , mean curvature flow
Aim To compare the shaping ability of three different nickel–titanium rotary instruments during the preparation of curved root canals in extracted teeth. Methodology A total of 60 root canals with curvatures ranging between 25° and 35° were divided into three groups of 20 canals. Based on radiographs taken prior to instrumentation, the groups were balanced with respect to the angle and the radius of canal curvature. Canals were prepared to a final apical size of 35 using M two, H yflex CM , and R evo‐ S . Using pre‐ and post‐instrumentation radiographs, straightening of the canal curvatures was determined with a computer image analysis program. Preparation time, changes of working length and instrument failures were also recorded. These data were analysed statistically using anova and Student–Newman–Keuls test. Results During preparation, no file fractured. M two and H yflex CM maintained the original canal curvature significantly better than R evo‐ S ( P < 0.05). Instrumentation with M two and H yflex CM was significantly faster than with R evo‐ S and resulted in less loss of working length ( P < 0.05), whilst no significant differences were obtained between M two and H yflex CM ( P > 0.05). Conclusions Under the conditions of this study, M two and H yflex CM respected the original canal curvature well and were safe to use. The use of R evo‐ S instruments required more time to prepare the curved canals and resulted in more pronounced canal straightening compared with M two and H yflex CM .