EFFECT OF ULTRASONIC VIBRATION ON POST REMOVAL IN EXTRACTED HUMAN PREMOLAR TEETH

The purpose of this study was to determine the effectiveness of ultras onic vibration in removing Paraposts from extracted teeth, Paraposts w ere cemented in mandibular premolars to a depth of 9 mm with zinc phos phate cement and the teeth placed in four groups, Group 1 received no vibration, Group 2 received vibration for 4 min, group 3 received vibr ation for 12 min, and group 4 received vibration for 16 min. Tensile f orces were applied to the posts and mean dislodgment forces compared, The mean force (kg) required to dislodge the Parapost in group 1 was 2 4.92 +/- 1.64 SEM; in group 2, 25.01 +/- 1.80; in group 3, 24.08 +/- 2 .29; and in group 4, 12.41 +/- 2.60, There was a significant differenc e between group 4 and groups 1 to 3 (p = 0.0003), Results of this stud y indicate that 16 min ultrasonic vibration is an effective method for removing Paraposts from human premolar teeth.