title: Analysis of nickel-titanium versus stainless steel instrumentation by means of direct digital imaging.
abstract: This study compared step-back preparations in curved canals using nickel-titanium (Ni-Ti) K-files and stainless steel K-files. Forty canals in mesial roots of mandibular molars were embedded in casting resin and cross-sectioned at three levels: 1 to 2 mm from the apical foramen, middle of the curve, and coronal. Direct digital computer images were recorded before and after instrumentation. Superimposition of the images combined with digital subtraction computer software allowed direct measurement of area instrumented, distance of transportation, and shape analysis. The computer software calculated absolute center of gravity for each image analyzed to get a full 360-degree interpretation of the canal transport. Time of instrumentation was recorded. Results showed Ni-Ti files to cause significantly less transportation and remain more centered at the apical level (p < 0.05). Area removed by Ni-Ti and stainless steel files was not significantly different (p < 0.05). Time of instrumentation was not significantly different for Ni-Ti and stainless steel instruments (p < 0.05). Cross-sectional shape of the instrumented canal was not significantly different (p < 0.05).
authors.affiliation: University of Texas-Houston, Department of Stomatology/Division of Endodontics 77030-3402, USA.
authors.forename: C L
authors.initials: CL
authors.lastname: Coleman
authors.forename: T A
authors.initials: TA
authors.lastname: Svec
authors.forename: M R
authors.initials: MR
authors.lastname: Rieger
authors.forename: J A
authors.initials: JA
authors.lastname: Suchina
authors.forename: M M
authors.initials: MM
authors.lastname: Wang
authors.forename: G N
authors.initials: GN
authors.lastname: Glickman
mesh_terms: D003722:Dental Alloys; D003762:Dental Instruments; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008334:Mandible; D008963:Molar; D009532:Nickel; D018915:Root Canal Preparation / Q000295:instrumentation*; D013193:Stainless Steel; D013223:Statistics as Topic; D014025:Titanium
chemical_list: D003722:Dental Alloys; C040654:titanium nickelide; D013193:Stainless Steel; D009532:Nickel; D014025:Titanium