The ability of the Reciproc R25 instrument to reach the full root canal working length without a glide path.

AIM To assess the frequency in which the Reciproc instrument reaches the full working length (FWL) of mandibular molar canals without a glide path. METHODOLOGY From a pool of mandibular molars, 253 root canals were classified as straight (G1) and, 249 root canals as moderately curved (G2) following Schneider's method. A R25 Reciproc instrument (VDW, Munich, Germany) was advanced in the canals without any previous glide path. All cases where Reciproc instruments reached the FWL were classified as 'Reaching the FWL' (RFWL). When the FWL was not reached by the R25, the root canals were classified as 'Not Reaching the FWL' (NRFWL). Pearson's χ(2) test compared (i) the frequency distributions of root canals classified as RFWL and NRFWL for each group and (ii) the frequency distributions of NRFWL canals between the groups. RESULTS In G1, 9 cases (3.56%) and in G2, 23 canals (9.34%) were classified as NRFWL. The difference between NRFWL and RFWL was significant in both groups (P = 0.00, χ(2) = 217.2 for G1; P = 0.00, χ(2) = 167.8 for G2). The frequency of NRFWL was significantly higher for G2 (P = 0.02, χ(2) = 5.452). CONCLUSION The R25 Reciproc instrument is able to reach the FWL of straight- and moderate-curved mandibular molar canals without a glide path in a large proportion of cases.

[1]  Susan Wolcott,et al.  Separation incidence of protaper rotary instruments: a large cohort clinical evaluation. , 2006, Journal of endodontics.

[2]  Computed micro-tomographic evaluation of glide path with nickel-titanium rotary PathFile in maxillary first molars curved canals. , 2012, Journal of endodontics.

[3]  John D West,et al.  The endodontic Glidepath: "Secret to rotary safety". , 2010, Dentistry today.

[4]  J. D. PÉcora,et al.  Influence of cervical preflaring on determination of apical file size in mandibular molars: SEM analysis. , 2008, Brazilian dental journal.

[5]  V. Faus-Matoses,et al.  In vitro comparison of cyclic fatigue resistance of ProTaper, WaveOne, and Twisted Files. , 2012, Journal of endodontics.

[6]  Giorgio Chiandussi,et al.  Use of nickel-titanium rotary PathFile to create the glide path: comparison with manual preflaring in simulated root canals. , 2009, Journal of endodontics.

[7]  F. Tay,et al.  Effect of clinical use on the cyclic fatigue resistance of ProTaper nickel-titanium rotary instruments. , 2007, Journal of endodontics.

[8]  WooCheol Lee,et al.  Cyclic fatigue and torsional resistance of two new nickel-titanium instruments used in reciprocation motion: Reciproc versus WaveOne. , 2012, Journal of endodontics.

[9]  S. W. Schneider,et al.  A comparison of canal preparations in straight and curved root canals. , 1971, Oral surgery, oral medicine, and oral pathology.

[10]  Jean-Paul Micallef,et al.  Location of contact areas on rotary Profile1 instruments in relationship to the forces developed during mechanical preparation on extracted teeth , 1999 .

[11]  Giulio Gavini,et al.  Resistance to flexural fatigue of Reciproc R25 files under continuous rotation and reciprocating movement. , 2012, Journal of endodontics.

[12]  O. Peters,et al.  ProTaper rotary root canal preparation: assessment of torque and force in relation to canal anatomy. , 2003, International endodontic journal.

[13]  G De-Deus,et al.  Extended cyclic fatigue life of F2 ProTaper instruments used in reciprocating movement. , 2010, International endodontic journal.

[14]  E. Kontakiotis,et al.  Prevalence and management of instrument fracture in the postgraduate endodontic program at the Dental School of Athens: a five-year retrospective clinical study. , 2008, Journal of endodontics.

[15]  G K Kulkarni,et al.  Accuracy of the DTC torque control motor for nickel-titanium rotary instruments. , 2004, International endodontic journal.

[16]  G. Cantatore,et al.  The influence of a manual glide path on the separation rate of NiTi rotary instruments. , 2005, Journal of endodontics.

[17]  Gianluca Gambarini,et al.  Cyclic fatigue of nickel-titanium rotary instruments in a double (S-shaped) simulated curvature. , 2012, Journal of endodontics.

[18]  E. Berutti,et al.  Influence of manual preflaring and torque on the failure rate of ProTaper rotary instruments. , 2004, Journal of endodontics.