Root canals shaped by nickel-titanium instrumentation with automated computerized numerical control systems

Area of Science:

• Endodontics
• Dental Materials Science
• Biomedical Engineering

Background:

• Root canal shaping is crucial for endodontic treatment success.
• Nickel-titanium (NiTi) files are commonly used for root canal preparation.
• Optimizing shaping techniques is essential to preserve root canal anatomy.

Purpose of the Study:

• To evaluate the efficacy of a nickel-titanium (NiTi) file system utilizing an automated computerized numerical control (CNC) system for root canal shaping.
• To compare different automated movement patterns and insertion angles for their impact on shaping ability.

Main Methods:

• Simulated resin root canals were shaped using a NiTi file with a CNC system.
• Four movement groups were tested: manual, vertical, reciprocating, and spiral CNC movements.
• Five different insertion angles were evaluated for their effect on shaping.
• Shaping ability was assessed by measuring changes in working length, central axis offset, curvature variation, and preparation time.

Main Results:

• The spiral up and down movement (Group 4) resulted in a smaller change in the central axis position in curved canals.
• Spiral movement and manual movement showed significantly reduced curvature changes and preparation time compared to vertical and reciprocating movements.
• A 5° insertion angle significantly minimized variations in working length and curvature.

Conclusions:

• Automated spiral movement controlled by a CNC machine, combined with a 5° insertion angle, provides superior precision in maintaining original root canal anatomy.
• This optimized automated NiTi file system demonstrates enhanced shaping ability compared to other tested methods.