Avaliação de protocolo usando ultrassom na remoção de retentores metálicos em dentes multirradiculares

Abstract

Among the techniques employed for the removal of the retainers, the ultrasonic vibration has been the most efficient. There is a lack of studies techniques for removing metal retainers in multirooted teeth. This study evaluated in vitro a removal protocol consisting of making a tunnel in the coronal portion of the retainer and application of ultrasound in this cavity. Forty molars were endodontically treated using single file system with reciprocating movement and filled using thermoplasticized technique, receiving cast intraradicular retainers and being allocated into 4 groups according to the removal protocol: GROUP I - no tunnel and no ultrasonic vibration, GROUP II - without tunnel and ultrasonic vibration in the coronal portion of the core, GROUP III - with tunnel and without ultrasonic vibration and GROUP IV - with tunnel and ultrasonic vibration inside the tunnel. The tensile test was performed on all samples in the EMIC DL-2000 universal testing machine with a speed of 1 mm / min values obtained in Newton and the data were statistically analyzed using ANOVA and Tukey- Kramer (p <0.05). The results showed statistically significant differences between the groups tested (GI - 322.74 N; GII - 283.09 N; GIII - 244.00 N; GIV - 237.69 N). The lowest average power was found in the group that was the ultrasonic vibration inside the tunnel.The results demonstrated that preparing the tunnel in the core and ultrasonic vibration within it reduces the force required for removing. This removal protocol was effective for removal intraradicular metal retainers multirooted teeth cemented with zinc phosphate.