AN IN VITRO STUDY OF THE EFFECTS OF DIFFERENT TORQUE VALUES APPLIED TO THE NICKEL TITANIUM ROTARY CANAL INSTRUMENTS FOR CURVED ROOT CANAL PREPARATION

Demet ALTUNBAŞ, Kerem Engin AKPINAR, Alper KUŞTARCI
2016 Atatürk Üniversitesi Diş Hekimliği Fakültesi Dergisi  
Aim: To evaluate the effects of different torque values applied to K3 and Mtwo instruments on curved canal preparation in vitro. Material and Methods: One-hundred-twenty resin blocks with curved canals were divided into two main groups in which K3 and Mtwo series were used. The main groups were then divided into three subgroups. Torque values were set at 20 gcm, 60 gcm and 120 gcm in the K3 group and 100 gcm, 150 gcm and 300 gcm in the Mtwo group. Pre-and post-instrumentation images were
more » ... posed and canal shape was assessed. Measurements were carried out at 5 different points: at the canal orifice (O); half-way to the orifice in the straight section (HO); beginning of the curve (BC); apex of the curve (AC); endpoint (EP). Results: In the K3 and Mtwo groups, the narrowest total width measurements were recorded at the subgroups that the torque was highest. In the K3 group, there were significant differences for the amount of resin removed from the outer curve at O, BC and AC; for the amount of resin removed from the inner curve at HO, BC, AC and EP. In the Mtwo group, significant differences were found for the amount of resin removed from the outer curve at HO, BC, AC and EP; and for the amount of resin removed from the inner curve at AC. Conclusion: K3 instruments shaped curved canals with minimal transportation, when the torque value increased; on the contrary, greater values of absolute transportation occured with Mtwo instruments.
doi:10.17567/dfd.86521 fatcat:xpbypmp7kncnvedakzusuetcbu