A COMPARISON BETWEEN 2 ROOT END PREPARATION TECHNIQUES IN HUMAN CADAVERS

The purpose of this study was to compare ultrasonic and bur root end c avity preparations with regard to retention, cleanliness, and root can al parallelism. Twenty anterior teeth from human cadavers were instrum ented and obturated with gutta-percha and sealer. After raising a full -thickness flap, the apices of the roots were exposed and beveled at a 45-degree angle. Half of the apical cavities were prepared with an ap propriate sized Carr alloy tip energized by an Amadent Ultrasonic unit . The other half was prepared with an inverted cone bur in a slow-spee d handpiece. The teeth were then extracted, sectioned longitudinally, photographed, and scanning electron micrographs examined. The ultrason ic cavities produced more parallel walls and deeper depths for retenti on. In addition, the ultrasonic tips followed the direction of the can als more closely than those prepared by burs. Scanning electron micros copic examination of the cavity walls showed presence of cleaner surfa ces of root end cavities prepared by ultrasonic tips than those made w ith burs.