RESUMO
Root canal preparation is an important process in endodontic therapy. Nickel-titanium [NiTi] rotary file system can be used in single length technique [simultaneous technique] without early coronal enlargement, as well as in crown-down method. The purpose of this in vitro study was to compare single length with crown-down methods' shaping ability using Mtwo NiTi files. Fifteen acrylic-resin blocks containing simulated canals were divided into two experimental groups. In group A, single length technique was used and in group B root canals were prepared by crown-down technique. Pre- and post-preparation canals were photographed in a standardized manner and were superimposed. The inner and outer walls of canal curvature were evaluated at three points [apical, middle and coronal] to determine the greatest change. The data was statistically analyzed using the Student t-test by Statistical Analysis System [SAS] software. Statistical analysis revealed that in group B, dentine was equally removed within the canal coronal to the curvature, whereas in group A, the inner wall was predominantly removed [P<0.01]. The two groups had no significant difference at the apical and middle points of the canal curvature. Our in vitro study revealed no significant difference between the single length method and crown-down technique using Mtwo for preparation of apical and middle portion of canal curvature
Assuntos
Preparo de Canal Radicular/instrumentação , Desenho de Equipamento , Cavidade Pulpar/anatomia & histologia , Propriedades de Superfície , Ligas DentáriasRESUMO
This study was carried out to compare the capability of K-files with Mtwo rotary file in terms of negotiation as well as depth of penetration in second mesiobuccal [MB2] canal of maxillary first molar. A total of 32 MB2 canal of maxillary first molars having different root curvatures [not more than 30 degree] and root lengths were selected and then detected by K-file no. 10, no.8 and no. 6. Based upon file penetration the samples were assigned into four groups. Group A: K-file no. 10 penetrate>2mm into coronal third, group B: K-file no. 10 could penetrate2mm penetration, group C: K-files no. 10 and 8 could penetrate = 0.01]. Mtwo rotary files could be an efficient substitute for hand files to negotiate MB2 canal both more easily and rapidly. To our knowledge, it is the first time that a NiTi rotary file showed success in negotiation of any canal