Comparing accuracy after guide access and microscope-assisted access for fiber post removal.

ABSTRACT

OBJECTIVES: This study compared the accuracy of the guide-supported and the microscope-assisted fiber post removal systems by using the extracted teeth. These new idea and theory can be used by clinicians to remove fiber posts. METHODS: Twenty-eight human extracted premolars were randomly divided into the guide and microscope groups. After root canal treatment and fiber post restoration, the fiber posts were removed by using a digital guide and via microscope-assisted ultrasonic instrument, respectively. Mimics 10.0 was used to measure the deviation, and the accuracy of the two fiber post removal systems were compared. RESULTS: In the guide group, the apical vertical deviation was 0.99 mm±0.52 mm, the apical horizontal deviation was 0.75 mm±0.19 mm, the angle deviation was 2.32°±0.64°, and the volume loss was 8.09 mm3±1.42 mm3. In the microscope group, the apical vertical deviation was 0.44 mm±0.23 mm, the apical horizontal deviation was 0.23 mm±0.07 mm, the angle deviation was 0.64°±0.31°, and the volume loss was 15.25 mm3±3.94 mm3. No significant difference was found in the apical vertical deviation between the two groups (P>0.05), whereas the apical horizontal deviation, the angle deviation, and the volume loss were significantly different between the two groups (P<0.05). CONCLUSIONS: The removal of fiber post supported by a digital guide helped reduce the volume loss of post-core restoration teeth, but its accuracy was lower than that of removal by using a microscope-assisted ultrasonic instrument.