Fogorvosi szemle, 2005 (98. évfolyam, 1-6. szám)
2005-06-01 / 3. szám
123 FOGORVOSI SZEMLE ■ 98. évf. 3. sz. 2005. hasonlításban mind a szövetkímélő megmunkálás, mind a gyökércsatorna alakjának megtartása szempontjából a nikkel-titánium eszközzel végzett gépi megmunkálást mutatják kedvezőbbnek. Feltehető azonban, hogy a gépi tágító módszerek és a teljes mértékben kézi tágító módszerek hatásának az összehasonlítása, azaz a Gates- Glidden fúrók elhagyása, megfelelőbb eredményt mutatna a megmaradó dentinfal-vastagság szempontjából, de a koronális hozzáférési forma („coronal flareing”) kialakítása jelentősen megnövelné a preparálási időt. Jelen feltételezés bizonyítása további vizsgálatokat igényel. Irodalom 1. Abou-Rass M, Frank AL, Glick DH: The anticurvature filing method to preparate the curved canal. J Am Dent Assoc 1980; 101: 792- 794. 2. Baumann MA; Nickel-titanium; options and challenges. In: Syngcuk K: Modern Endodontic Practice. Dent Clin North Am 2004; 48: 55-67. 3. Buchanan Ls: Cleaning and shaping of the root canal system. In: Cohen S, Burns RC, eds. Pathways of the pulp. 5th ed. St Louis: The CV Mosby Company, 1991: 166. 4. Card SJ, Sigurdsson A, Orstavik D, Trope M: The Effectiveness of increased apical enlargement in reducing intracanal bacteria. J Endodon 2002; 28: 779-783. 5. Coffae Kp, Brilliant JD: The effect of serial preparation versus nonserial preparation on tissue removal in the root canals of extracted mandibular human molars. J Endodon 1975; 6: 211-214. 6. Coleman CL, Svec TA: Analysis of NiTi versus stainless steel instrumentation in resin simulated canals. J Endodon 1997; 23:232-235. 7. Dalton BC, Orstavik D, Phillips C, Pettitte M, Trope M: Bacterial reduction with nickel-titanium rotary instrumentation. J Endodon 1998; 24: 763. 8. Fabiani C, Pisacane C, Boschi M, Franco V: Nickel-titanium vs. stainless steel: comparison of four instrumentation techniques on canal transportation. J Endodon 1998; 24: 277. 9. Glossen CR, Haller RH, Dove SB, del Rio CE: A comparison of root canal preparations using NiTi hand, NiTi engine driven and K-Flex endodontic instruments. J Endodon 1995; 21:146-151. 10. Kerekes K, Tronstad L: Morphometric observations on the root canals of human molars. J Endodon 1977; 3:114-118. 11. Kum KY, Spänberg L, Cha BY, Young Jll, Seng-Jong L, Chan-Young L: Shaping ability of three ProFile rotary instrumentation techniques in simulated resin root canals. J Endodon 2000; 26: 719-723. 12. Lim KC, Webber J: The effect of root canal prepapration on the shape of the curved root canal. Int EndodJ 1985; 233-239. 13. Peter OA, Barbakow F: Effects of irrigation on debris and smear layer on canal walls prepared by two rotary techniques: a scanning electron microscopic study. J Endodon 2000; 26: 6-10. 14. Roane JB, Sabala CL, Duncanson MG: The ’balanced force’ concept for instrumentation of curved canals. J Endodon 1985; 11: 203-211. 15. Schilder H. Cleaning and shaping the root canal. Dent Clin North Am 1974; 18: 269-296. 16. Short JA, Morgan LA, Baumgartner JC: A comparison of the effects on canal transportation by four instrumentation techniques. J Endodon 1997; 23: 503-507. 17. Stock CJR, Gulabivala K: Preparation of the root canal. In: Stock CJR, Gulabivala K, Walker RT, Goodman JR: Endodontics. 2nd ed Mosby-Wolfe, New York, 1997: 95-145. 18. Stock CJR, Nehammer CF: Endodontics in practice. Budapest: Medicina, 1995: 49-57. 19. Veltri M, Mollo A, Pini PP, Ghelli LF, Balleri P: In vitro comparison of shaping abilities of ProTaper and GT Rotary Files. J Endodon 2004; 30: 163-166. 20. Walia H, Brantly WA, Gerstein H: An initial investigation of the bending and torsional properties of nitinol root canal files. J Endodon 1988; 14: 346-351. 21. Weine FS, Kelly RF.Lio PJ. The effect of preparation procedures on original canal shape and apical foramen shape. J Endodon 1975; 1 :255-262. 22. Wu M, Wesselink PR: Efficacy of three techniques in cleaning the apical portion of curved root canals. OraiSurg, Oral Med, Oral Pathol 1995; 79: 492-496. Dr. Krajczár K, Dr. Tóth V, Dr. Nyárády Z, Dr. Szabó Gy: In Vitro Comparison of Root Canal Preparation with Step-Back Technique and GT Rotary File - a Nickel-Titanium Engine Driven Rotary Instrument System The aim of the authors’ study was to compare the remaining root canal wall thickness and the preparation time of root canals, prepared either with step-back technique, or with GT Rotary File, an engine driven nickel-titanium rotary instrument system. Twenty extracted molars were decoronated. Teeth were divided in two groups. In Group 1. root canals were prepared with step-back technique. In Group 2. GT Rotary File System was utilized. Preoperative vestibulo-oral X-ray pictures were taken from all teeth with radiovisiograph (RVG). The final preparations at the mesiobuccal canals (MB) were performed with size #30 and palatinal/distal canals with size #40 instruments. Postoperative RVG pictures were taken ensuring the preoperative positioning. The working time was measured in seconds during each preparation. The authors also assessed the remaining root canal wall thickness at 3, 6 and 9 mm from the radiological apex, comparing the width of the canal walls of the vestibulo-oral projections on pre- and postoperative RVG pictures both mesially and buccally. The ratios of the residual and preoperative root canal wall thickness were calculated and compared. The largest difference was found at the MB canals of the coronal and middle third level of the root, measured on the distal canal wall. The ratio of the remaining dentin wall thickness at the coronal and the middle level in the case of step-back preparation was 0,605 and 0,754, and 0,824 and 0,895 in the cases of GT files respectively. The preparation time needed for GT Rotary File System was altogether 68,7% (MB) and 52,5% (D/P canals) of corresponding step-back preparation times. The use of GT Rotary File with comparison of standard step-back method resulted in a shortened preparation time and excessive damage of the coronal part of the root canal could be avoided. Key words: GT Rotary File, step-back technique, NiTi
