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Comparison of hand and rotary instrumentation for removing gutta‐percha from previously treated curved root canals: a microcomputed tomography study
Author(s) -
Rödig T.,
Kupis J.,
Konietschke F.,
Dullin C.,
Drebenstedt S.,
Hülsmann M.
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.12128
Subject(s) - root canal , dentistry , molar , materials science , gutta percha , instrumentation (computer programming) , endodontic retreatment , orthodontics , dental instruments , mathematics , medicine , nuclear medicine , computer science , operating system
Aim To compare the efficacy of hand and rotary nickel–titanium ( N i T i) instruments in removing filling material from curved root canals of root filled teeth with unknown preparation parameters. Methodology Ninety mandibular molars with root fillings in curved root canals and homogenous root canal filling extending to 0‐2 mm short of the radiographic apex were selected. Root canal curvatures and radii were measured in two directions and microcomputed tomography (micro‐ CT ) scans were used to determine preoperative volumes of the filling material. Subsequently, the teeth were assigned to two identical groups ( n = 14). The root fillings were removed with H edström files or F lex M aster N i T i rotary instruments. Postoperative micro‐ CT imaging was used to assess the percentage of residual filling material as well as the amount of dentine removal. Working time and procedural errors were recorded. Data were compared using analysis of covariance and analysis of variance procedures. Results Root canals retreated with H edström files were associated with less remaining filling material compared with F lex M aster instruments ( P < 0.05). Both retreatment techniques removed similar amounts of dentine with no significant differences ( P > 0.05). Flex M aster instruments were significantly faster than H edström files ( P < 0.05). No procedural errors were detected in the H edström group, whilst three instruments fractured in the F lex M aster group. Conclusions Hand instrumentation resulted in significantly less residual filling material than retreatment with rotary N i T i instruments. Dentine removal was not significantly different for both techniques. Flex M aster N i T i rotary files were significantly faster than H edström files, but were associated with a higher risk of instrument fracture.