Análise da eficiência da vibração ultrassônica na remoção de retentores intrarradiculares fundidos confeccionados com diferentes ligas metálicas

Abstract

This study evaluated in vitro the efficiency of ultrasonic vibration to remove casting radicular post made of different metal alloys. Forty-eight human maxillary canines were endodontically treated and received fused metal radicular post. The teeth were divided into 4 groups of 12 elements each: GI - nickel-chromium retainers without ultrasonic vibration; GII - copper-aluminum retainers without ultrasonic vibration; GIII - nickel-chromium retainers with ultrasonic vibration; G IV - copper-aluminum retainers with ultrasonic vibration. After the zinc phosphate cement was held ultrasonic vibration was performed on the holders of groups III, IV for 1 minute. The bodies of the test piece was subjected to tensile test in a universal testing machine with a speed of 1 mm / min. The maximum tensile force required to remove the retainer was recorded in Newton and the data were statistically analyzed using ANOVA and Tukey-Kramer. Results: The results showed statistically significant differences between the tested groups (GI - 361.38 N; GII - 445.05 N; GII - 445.05 N; GIV - 346.37N), and alloys of Copper-Aluminum had higher average force before the ultrasonic vibration and the Nickel-Chrome alloys had greater reduction after the application of ultrasound such being more affected than Copper-Aluminum alloys. Conclusion: The ultrasonic vibration showed higher effectiveness in reducing the required pull force to remove retainers made of alloys of Nickel-Chrome front those fused with Copper-Aluminum in single-rooted teeth.