Purpose: to evaluate the prepared surface areas of oval-shaped root canals in mandibular molars using different instrumentation techniques.
N= 48 mandibular molars (12/group)
- Inclusion criteria: 1formaina in D root, canal ratio of more than 2, curvature less than 20.
- Teeth were scanned by micro CT. instrumentation done by 1 operator.
- H/CF: circumferential filing by hedstrom files to #40. (each file was moved at least twice).
- 3 other groups used protaper universal to F4. PT/1:instrumented as 1 canal, PT/2: as 2 canals. PT/CH: circumferential. Post micro CT was taken and superimposed on the previous one.
- After that PT/1: circumferential filling was done using hedstrom #30,#40.
- After canal shaping was completed, canals were irrigated with a final sequence of 2.5% NaOCl, 17% EDTA, and 2.5% NaOCl (5 mL each).
Most highlighted Results:
- There was no difference in volume after preparation among groups.
- Unprepared area PT/1 (80%), PT/2 (60%)
- No significant difference in the amount of unprepared root surface in the apical 4 mm.
- Additional circumferential filing with hedstrom files in PT/1 decreased the fraction of unprepared to 69% .
Well designed study, that showed that instrumenting the D canal as 2 canals would reduce the % of unprepared area.