A comparison of four instrumentation techniques on apical canal transportation.

The ability of four instrumentation techniques to enlarge and maintain the central axis of 51 curved canals was evaluated radiographically. Curved canals in extracted human teeth were instrumented using a step-back preparation with K-files, crowndown preparation with K-files, sonic instrumentation with Shaper-Sonic files, and the NiTiMatic preparation system. Following coronal preflaring, each canal was instrumented to a #35 file 1 mm from the anatomic foramen. Radiographs were taken with mercury filling the canal system using a specially designed model that allowed for the pre- and postinstrumentation canal to be viewed on the same radiograph. Canal enlargement and apical transportation resulting from the various instrumentation techniques were evaluated using computer analysis. No statistically significant differences were found for canal transportation. Sonic instrumentation significantly increased coronal flaring. The crown-down and sonic techniques produced more ledges. Elbow formation was associated with all instrumentation techniques. The model system developed for this study provided an accurate method of assessing the preparation techniques and the instrument effects on the canal walls.

[1]  F S Weine,et al.  The effect of preparation procedures on original canal shape and on apical foramen shape. , 1975, Journal of endodontics.

[2]  J. Simon,et al.  A comparison of the effect of modified and nonmodified instrument tips on apical canal configuration. Part II. , 1988, Journal of endodontics.

[3]  Stephen Cohen,et al.  Pathways of the Pulp , 1976 .

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

[5]  A. R. Williams,et al.  Effects of constraint on the oscillatory pattern of endosonic files. , 1989, Journal of endodontics.

[6]  H. Gerstein,et al.  An initial investigation of the bending and torsional properties of Nitinol root canal files. , 1988, Journal of endodontics.

[7]  L. Morgan,et al.  An evaluation of the crown-down pressureless technique. , 1984, Journal of endodontics.

[8]  R. Oswald,et al.  A radiographic comparison of two root canal instrumentation techniques. , 1992, Journal of endodontics.

[9]  R. Walton.  Histologic evaluation of different methods of enlarging the pulp canal space. , 1976, Journal of endodontics.

[10]  S. Montgomery,et al.  The effect of endosonic instrumentation in simulated curved root canals. , 1987, Journal of endodontics.

[11]  L Tronstad,et al.  Morphometric observations on the root canals of human molars. , 1977, Journal of endodontics.

[12]  K. Lim,et al.  The effect of root canal preparation on the shape of the curved root canal. , 1985, International endodontic journal.

[13]  M. Tang,et al.  The effects of hand, sonic and ultrasonic instrumentation on the shape of curved root canals , 1989 .

[14]  E Sonnabend,et al.  The influence of different root canal instruments on root canal preparation: an in vitro study. , 1991, International endodontic journal.

[15]  D. Southard,et al.  Instrumentation of curved molar root canals with the Roane technique. , 1987, Journal of endodontics.

[16]  J B Roane,et al.  The "balanced force" concept for instrumentation of curved canals. , 1985, Journal of endodontics.

[17]  T. Fogarty,et al.  Effect of preflaring on canal transportation. Evaluation of ultrasonic, sonic, and conventional techniques. , 1991, Oral surgery, oral medicine, and oral pathology.

[18]  G B Pelleu,et al.  Effect of three file types on the apical preparations of moderately curved canals. , 1988, Journal of endodontics.

[19]  R. Walton,et al.  An in vitro histological comparison of the step-back, sonic, and ultrasonic instrumentation techniques in small, curved root canals. , 1987, Journal of endodontics.