Aim: The aim of this study was to compare the effects of two different rotary systems on the original canal curvature by means of three different root canal curvature measurement techniques. Materials and Method: Mesiobuccal canals of thirty extracted human mandibular first and second molar teeth were equally allocated into two groups: Mtwo or ProTaper. After embedding in clear acrylic resin, preoperative radiographs were taken. Both systems were used according to the manufacturers’ instructions. Pre- and postoperative angular and linear values of mesiobuccal canals were obtained from radiographs using AutoCAD R12. Results: In both groups, the postoperative canal access angle (CAA) and Schneider angle (SA) were significantly decreased (p≤ 0.005). Postoperative AC distance (the distance between canal entrance and the point that the canal begins to move away from the long axis) significantly increased only in the ProTaper group (p=0.005). Conclusion: The lack of a change in the AC distance in the Mtwo group indicated that the original canal curvature was maintained. Postoperative AC distance should also be measured, besides CAA and SA, in order to evaluate changes in the root canal curvature after root canal preparation.
Amaç: Bu çalışmanın amacı iki farklı döner eğe sisteminin, orijinal kök kanal eğimi üzerindeki etkilerinin üç farklı kök kanal eğimi ölçüm tekniği ile karşılaştırılarak incelenmesidir. Gereç ve Yöntem: Otuz adet çekilmiş alt çene birinci ve ikinci büyük azı dişinin meziyobukkal kanalları Mtwo veya ProTaper ile şekillendirilmek üzere eşit olarak iki gruba ayrılmıştır. Dişler şeffaf akrilik rezin içine gömüldükten sonra pre-operatif radyografileri çekilmiştir. Her iki döner eğe sisteminin eğeleri üretici firma talimatları doğrultusunda kullanılmıştır. Meziyobukkal kanalların başlangıç ve işlem sonrası açısal ve doğrusal değerleri AutoCAD R12 programı kullanılarak radyografiler üzerinden hesaplanmıştır. Bulgular: Her iki grupta da genişletme sonrası kanal giriş açıları (CAA) ve Scheider açıları (SA) anlamlı derecede azalmıştır (p≤ 0.005). Genişletme sonrası AC uzunluğu (kanal girişi ile kanalın uzun aksından ayrılmaya başladığı nokta arası mesafe) sadece ProTaper gurubunda belirgin olarak artmıştır (p=0.005). Sonuç: Mtwo grubunda AC uzunluğunda değişiklik olmaması kanalın orjinal eğimini koruduğunu göstermektedir. Kök kanal şekillendirilmesi sonrası kanal eğimlerindeki değişikliklerin ölçülmesinde CAA ve SA açılarının yanısıra işlem sonrası AC uzunluğu da ölçülmelidir.
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