EVALUATION OF 2 NICKEL-TITANIUM INSTRUMENT SYSTEMS IN SHAPING ROOT CANALS

Evaluation of 2 Nickel-Titanium Instrument Systems in Shaping Root Canals Abstract Objective: To evaluate root canal enlargement following mechanical shaping using 2 nickel titanium rotary systems in simulated curved canals. Material and Method : Thirty simulated canals in resin blocks were divided into two experimental groups, each comprising 15 resin blocks, and prepared with Twisted files (TF) and RaCe rotary files using crown-down technique. Preoperative and postoperative photographs, taken using a digital camera, were superimposed and aberrations were recorded. The amount of resin removed was measured at 11 different points, beginning at the apical terminus of the canal. Instrument failure, outer and inner width measurements, transportation rate, and centering ability were recorded on each central canal path and differences between groups were statistically analyzed using Student’s t test. Results: No instrument fracture occurred during preparation. RaCe instruments removed more material from the outer canal walls in the apical section (p 0.05). Conclusions: RaCe instruments removed more resin from the outside of the apical curvature and from the inner side of the coronal curvature compared to TF. In addition, mean transportation amount was significantly high for RaCe in middle section (i.e., coronal curvature). Regarding canal centering ability, however, both instruments retained original canal geometry and performed similarly. Key words: Twisted File, RaCe, Curved root canals, Canal transportation, Centering ability, Ni-Ti rotary systems Kok Kanallarini Şekillendirmesinde Iki Nikel Titanyum Alet Sisteminin Degerlendirilmesi Amac: Simule edilmis egri kanallarda 2 nikel titanyum doner alet sistemi kullanilarak mekanik sekillendirme sonrasi kok kanal genislemesinin degerlendirilmesi. Gerec ve Yontem : Recine bloklardaki otuz adet simule edilmis kanal, her biri 15 adet rezin blogu iceren iki deney grubuna ayrildi ve Twisted files (TF) ve RaCe doner egeleri kullanilarak crown-down teknigiyle sekillendirildi. Bir dijital kamera kullanilarak cekilen preoperatif ve postoperatif fotograflar cakistirildi ve sapmalar kaydedildi. Kaldirilan rezin miktari, kanalin apikal sonlanmasindan baslayarak 11 farkli noktada olculmustur. Her bir kanal yolundaki dis ve ic genislik olcumleri, transportasyon orani, merkezde kalma yetenegi ve alet kirigi kaydedildi ve gruplar arasindaki farklar Student t testi kullanilarak istatistiksel olarak analiz edildi. Bulgular: Preparasyon sirasinda alet kirilmasi meydana gelmedi. RaCe egeleri TF’e kiyasla kanallarin apikal kisimdaki dis kanal duvarlarindan (p 0.05). Sonuclar: RaCe egeleri TF’e kiyasla, apikal kurvaturun disindan ve koronal kurvaturun ic kismindan daha fazla rezin kaldirmistir. Ek olarak, ortalama transportasyon miktari orta kisimda RaCe icin anlamli derecede yuksekti (yani koronal egrilik). Bununla birlikte kanalin merkezinde kalma yetenegi ile ilgili olarak, her iki enstruman da orijinal kanal geometrisini korudu ve kanali benzer sekilde sekillendirdi. Anahtar kelimeler: Twisted File, RaCe, Egri kok kanallari, Kanal transportasyonu, Merkezde kalma yetenegi, Ni-Ti doner alet sistemleri