Abstract
BackgroundTo investigate the efficacy of a nickel-titanium (NiTi) file with an automated computerized numerical control (CNC) system for root canal shaping.MethodsThe movement of the automated device and the insertion angle were investigated. In Experiment 1, simulated resin root canals were randomly divided into four groups (n = 20): manual downward movement using a handpiece (Group 1), vertical downward movement by CNC (Group 2), reciprocating up and down movement by CNC (Group 3), and spiral up and down movement by CNC (Group 4). In Experiment 2, five different insertion angles of the NiTi file were evaluated (n = 20). Four parameters were used to evaluate the shaping ability: change in the working length, central axis offset, curvature variation, and preparation time. Groups were compared using one-way analysis of variance (ANOVA) with significance was set at P < 0.05.ResultsThe change in central axis position in the curved part of the root canal was found to be smaller in Group 4 than in other groups (P < 0.05). The curvature changes and preparation time of Groups 1 and 4 were significantly reduced compared with Groups 2 and 3 (P < 0.05). The variation in working length and curvature in the 5° insertion angle group was significantly smaller than in the other groups (P < 0.05).ConclusionsA spiral up and down movement, controlled by the CNC machine, and 5° insertion angle, maintained original root canal shape more precisely than other methods.
Highlights
To investigate the efficacy of a nickel-titanium (NiTi) file with an automated computerized numerical control (CNC) system for root canal shaping
Recent studies have confirmed that NiTi instruments have better root canal shaping ability when they are used in a reciprocating motion rather than in continuous rotation [8, 9]
Hwang et al found through micro-computed tomography that the greatest deviation of canal centers and root tips in canals occurred with continuous rotation [11]
Summary
To investigate the efficacy of a nickel-titanium (NiTi) file with an automated computerized numerical control (CNC) system for root canal shaping. Yared et al proposed a reciprocating movement of the NiTi instrument at 144° clockwise and 72° counterclockwise [7]. Recent studies have confirmed that NiTi instruments have better root canal shaping ability when they are used in a reciprocating motion rather than in continuous rotation [8, 9]. Franco et al found that in curved canals there was more unnecessary distortion of the lateral walls when instruments were used in continuous rotation. They concluded that reciprocation was superior to continuous rotation in the preparation of simulated root canals [10]. Hwang et al found through micro-computed tomography that the greatest deviation of canal centers and root tips in canals occurred with continuous rotation [11]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
