A comparative study on the shaping ability of three endodontic rotary Nickel-Titanium systems and stainless- steel hand K-flexofile in simulated curved canals

Abdul Karim .J. Al-Azzawi, Hamid Kassim


Background: The purpose of this study is to compare the Shaping ability of three rotary endodontic nickel-titanium systems (Pro- File, CT and Protaper) with stainless steel hand K-flexofile in simulated curved canals at different levels, this include total canal diameter, outer and inner transportations and centering ratio (the ability of the instruments to remain centered in the shaped canals).
Materials and method: Eighty simulated curved canals made of clear polyester resin were used to assess instrumentation.The acrylic blocks were divided into four groups, 20 simulated canals for each group were enlarged from #10 to # 25. In the first three groups all NiTi rotary instruments were set into a permanent rotation with a 16:1 reduction handpiece powered by a torque- limited electric motor set at 300 rpm. All the instruments were used in a crown down manner using a gentle in-and-out (peck- ing) motion. In the fourth group the simulated canals were instrumented with stainless steel K-flexo-files by using balanced force technique. Each simulated canal was filled with a drawing ink using to increase the color contrast for photographic documentation. Photographs of the unprepared canals were taken by the aid of stereomicroscope and digital camera at magnification of 40 times. When instrumentation of the canals was completed, the canals were injected again with the drawing ink and the image proce- dure is repeated. Pre- and postoperative digital photographs of the resin blocks were accomplished using Adobe Photoshop CS2 software program. At this stage the amount of resin removed i.e. the difference between the canal configuration before and after instrumentation was determined for both the inner and the outer side of the curvature at five reference points.
Results: For total canal diameter there was highly significant difference among the four groups at all levels. For outer canal trans- portation there was highly significant difference among the four systems at all levels except at the second level where the differ- ences were not significant. For inner transportation there was highly significant difference among the four groups at all levels. For centering ratio there was highly significant difference among the tested groups at all level.
Conclusion: K-flexofile scored the maximum canal diameter at the apical two levels. ProTaper prepared the largest canal diameter at all levels. In comparison with ProTaper, canals prepared by GT and ProFile maintained original curvature was better with less straightening. The ability of instruments to remain centered in prepared canals was significantly better in NiTi systems than K- flexofiles. ProTaper files have lower centering ability than GT and ProFile.

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Ayar L, Love R. Shaping ability of ProFile and K3 rotary NiTi instruments when used in a variable tip sequence in simulated curved root canals .International Endodontic Journal 2004, 37, 593-601.

Sungcuk K. Modem endodontic practice. Dental Clinics of North America 2004(48).p:XI, 13, 24, 55-58, 59, 61, 63, 64, 66, 68-70, 74-76, 139, 141, 165, 166, 185, 282, 285.

Pruett J, Clement D, Games D. Cyclic -fatigue testing of nickel-titanium endodontic instruments. Journal of Endodontics 1997, 23, 77-85.

Roan J, Sabala C, Duncanson M. The balanced force concept for instrumentation of curved canals. Journal of Endodontics 1985, 11 (5), 203-11.

Calberson F, Deroose C, Hommez G, Raes H, DeMoor R. Shaping ability of GT rotary files in simulated resin root canals. International Endodontic Journal 2002, 35, 607-14.

Calhoun G, Montgomery S. The effects of four instrumentation techniques on root canal shape. Journal of Endodontics 1988, 14(6), 273-7.

Schafer E, Schlingemann R. Efficiency of rotary nickel titanium K3 instruments compared with stainless steel hand K-Flexo- file. Part 2. Cleaning effectiveness and shaping ability in severely curved root canals of extracted teeth. International Endodon- tic Journal 2003, 36, 208-217.

Perez F, Schoumacher M, Peli J.Shaping ability of two rotary instruments in simulated canals:stainless-steel ENDOflash and nickel-titanium HERO Shaper.International Endodontic Journal 2005,38,637-644.

Abou-Rass M, Frank A, Glick D. The anticurvature filing method to prepare the curved root canal. J Am Dent Assoc 1980,101 (5), 792-4.

Al-OmaniM,BryantS,DummerP.TheshapingabilityofGTrotaryNiTiinstruments.InternationalEndodonticJournal2003, 36,933.

Bergmans L, VanCleyn J, Beullens M, Wevers M, VanMeerbeek B, Lambrechts P. Progressive versus constant tapered shaft design using NiTi rotary instruments. International Endodontic Journal 2003, 36,288-95.

Garip Y, Gencoglu N. Comparison of curved canals preparations using ProFile, GT and Hero 642 rotary files. Journal of Oral Rehabilitation 2006, 33,131-136.

Rodig T, Hulsmann M, Kahlmeier C. Comparison of root canal preparation with two rotary NiTi instruments: ProFile .04 and GT Rotary. International Endodontic Journal 2007, 40,553-562.

Tasdemir T, Aydemir H, Ivan U, Unal 0. Canal preparation with Hero 642 rotary NiTi instruments compared with Stainless’ steel hand K-instrument assessedusing computed tomography International Endodontic Journal 2005,38 (2),402 8.

15GuelzowA,Stamm0,MartusP,KielbassaA.Comparativestudyofsixrotarynickel-titaniumsystemsandhandinstrumen- tation for root canal preparation. International Endodontic Journal 2005, 38 (10), 743-752.

SchaferE.RelationshipbetweendesignsfeaturesofendodonticinstrumentsandtheirpropertiespartI,cuttingefficiency.Jour- nal of Endodontics 1999, 25 (1), 52-55.

Yang G, Zhou X, Zhang H, Wu H. Shaping ability of progressive versus constant taper instruments in simulated root canals. International Endodontic Journal 2006, 39, 791-799.

YunH,KimS.Acomparisonofshapingabilitiesof4nickel-titaniumrotaryinstrumentsinsimulatedrootcanals.OralSurgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontics 2003, 95 (2), 228-33.

Tepel J, Schafer E, Hoppe W. Properties of endodontic hand instruments used in rotary motion part III, resistance to bending and fracture. J Endod 1997, 23 (3), 141-45.

ParkH.AcomparisonofGT,ProFiles,andstainless-steelfilestoshapedcurvedrootcanals.OralSurgery.OralMedicine,Oral Pathology and Endodontics 2001, 91,715-8.

DOI: http://dx.doi.org/10.26477/idj.v34i2.161


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