Canal-centring ability of three rotary file systems in simulated curved canals: a comparative study.
OBJECTIVE
To compare the canal-centring ability of M two , ProFile and RaCe rotary files, in simulated curved canals.


METHODS
About 30 simulated canals were prepared by M two , ProFile and RaCe rotary files. Pre and post-operative pictures were super-imposed and transportations recorded. Measurements were carried out at five different points: Canal orifice (O); half-way to the orifice in the straight section (HO); the beginning of the curve (BC); the apex of the curve (AC); the end point (EP). Intra- and inter-group comparisons were carried out by Wilcoxon;s signed ranks test and Kruskal-Wallis test respectively, using SPSS 14.0 software.


RESULTS
ProFile did not change canal centricity in any point. RaCe kept centricity at HO, BC, AC and EP. M two changed canal centricity in points BC, AC and EP. M two group kept the centricity significantly less than the other two groups at BC (P = 0.004), AC (P = 0.015) and EP (P = 0.01). There was no significant difference between these three rotary files at HO. However, the difference between RaCe, M two and ProFile was significant at O (P = 0.015).


CONCLUSIONS
ProFile and RaCe rotary files remained better centred than M two rotary files.
Khalilak
Zohreh
Z
Department of Endodontics, Dental School, Islamic Azad University, Tehran, Iran.
Alavi
Kaveh
K
Akhlaghi
Nahid Mohammad Zadeh
NM
Mehrvarzfar
Payman
P
Dadresanfar
Bahareh
B
D003786:Dental Pulp Cavity / Q000033:anatomy & histology*; D003804:Dentin / Q000033:anatomy & histology; D004867:Equipment Design; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008422:Materials Testing; D009811:Odontometry; D018915:Root Canal Preparation / Q000295:instrumentation* / Q000379:methods; D012399:Rotation; D013499:Surface Properties; D019227:Tooth Apex / Q000033:anatomy & histology