Teaching Two Rotary Nickel-Titanium Instrumentation Techniques to Graduate Dentists: Assessment of Learning...

The Arithmetic Crown-down Dynamic tactile Technique (ACDT) was proposed to shape severely curved canals. In this technique, a formula was proposed to calculate the maximum insertion depths of higher tapered instruments to prevent overflaring and preserve pericervical dentin. This study aims to compare the teachability, application, and incidence of procedural errors between the ACDT and the single-length technique (SLT) among dental interns.

Training on the ACDT and the SLT was provided to 339 dental interns. Each intern was assigned to shape 4 curved canals in extracted human molars (2 canals with each technique). An 8-question survey was provided to assess the ease of each technique. Furthermore, procedural errors during the instrumentation were recorded. Statistical significance was set at α=.05.

A significantly higher percentage of participants found learning the ACDT more difficult than the SLT (P < .001). Furthermore, participants found the ACDT more challenging than the SLT (P < .001). Participants preferred the SLT when treating easy (60%) to moderate (57%) cases. However, most participants preferred the ACDT for severe cases (82%) and considered the ACDT a safer instrumentation technique (79%). Among canals instrumented using the ACDT and the SLT, the ACDT had significantly fewer shaping-related errors than the SLT (P < .001). The total number of files showing deformation was significantly less with ACDT.

The SLT was easier to learn and apply than the ACDT. The ACDT was safer when shaping curved canals, and dental interns had more confidence in ACDT when shaping severely curved canals.