Summary :
Purpose: to quantitatively assess canal preparation outcomes achieved by the single-file F2 ProTaper technique, engine-driven under reciprocating movement.
N= 25 extracted mandibular first molars.
Materials /Methods:
•Inclusion criteria: teeth with 2 mesial root canals & separate apical foramina, and mesial canal curvatures between 20- 40 degrees.
•Root canals were randomly assigned to group 1 ( Protaper full sequence instruments) and group 2 (Reciprocate instrumentation with Single file ProTaper F2).
•The teeth were scanned by preoperatively by mico-computed tomography.
In G1: A glide path was established by using a size 10 and 15 K-file to full WL. Then, canals were instrumented using S1, S2, F1, and F2 to full WL.
In G2: The root canal preparation was performed with one ProTaper F2 in clockwise (0.4 a circle) and counterclockwise (0.2 a circle) motion.
•After preparation, the canals were scanned & assessed for the following parameters: changes in dentin volume, percentage of shaped canal walls, degree of canal transportation & the time required to reach working length
Most highlighted Results:
- There were no statistical differences between the 2 preparation techniques in the anatomical parameters assessed (P > .01), except for a significantly higher canal transportation caused by the reciprocating file in the coronal canal third.
- Also, preparation was faster by using the single-file technique (P < .01).
Clinical significance:
According to the findings of this study , the single file approach can mechanically shape the root canal effectively in short time. However, the debridement of the canals was not addressed.

