A comparison of Er, Cr: YSGG laser with ultrasonic preparation on the seal of retrograde cavities.
OBJECTIVE
The aim of this in vitro study was to compare Er, Cr: YSGG laser with ultrasonic preparation on the seal of retrograde cavities.


METHODS
Twenty-eight maxillary anterior teeth were used in this study. After removing the crowns, the canals were prepared with the step-back technique and filled with guttapercha. Three millimeters below the apex; each root was cut with a fissure diamond bur. The root surfaces were then covered with nail polish and three millimeters deep retrograde class I cavities were prepared, using Er, Cr: YSGG laser (group L=12 roots) or ultrasonic retro-tip (group U=12 roots). Four roots were arranged for negative and positive control groups. Retrograde cavities were then filled with mineral trioxide aggregate (MTA) and teeth were placed in 2% methylene blue dye for 72 hours. The amount of dye penetration in sagittal sections of each tooth was measured with a stereomicroscope. An independent sample t-test was used for statistical analysis.


RESULTS
Cavities prepared with the Er, Cr: YSGG laser (1.61 + 0.81) showed significantly less micro-leakage than those prepared with the ultrasound (2.55+ 1.84) (P value =0.02).


CONCLUSIONS
Under the conditions of this research, the use of Er, Cr: YSGG laser for retrograde cavity preparation causes significantly less apical leakage and may increase the success rate of endodontic surgeries.
Department of Endodontic, Dental School, Islamic Azad University.
Nasrin
N
Roghanizad
Laser Research Center of Medical sciences, AJA university of Medical Sciences.
Reza
R
Fekrazad
Laser Research Center in Dentistry, Dental Faculty, Tehran university of medical sciences.
Katayoun Am
KA
Kalhori
Department of Endodontics, Dental School, Islamic Azad University.
Zohreh
Z
Khalilak
General dentist, Tehran.
Maryam Ali
MA
Esmaeili
University of São Paulo, Institute of Physics São Carlos (IFSC).
Rosane
R
de Fatima Zanirato Lizarelli
Er, Cr: YSGG laser; Retrograde cavities; Root end preparation; Ultrasound