RESUMEN
AIM: The aim of this study was to evaluate the influence of ultrasound during the removal of posts cemented with either zinc phosphate cement, glass ionomer cement or resin cement. METHODOLOGY: Eighty-four single-rooted teeth were prepared and after cementation of cast posts, they were randomly divided into six groups of 14. Group 1, 2 and 3 did not receive ultrasonic vibration, whilst groups 4, 5 and 6 received ultrasonic vibration for 10 min. The force necessary for post removal was determined using a universal testing machine. Results were statistically analysed using ANOVA and Tukey tests (5%). RESULTS: The application of ultrasonic vibration reduced the retention provided by zinc phosphate and glass ionomer cements by 39% and 33%, respectively. CONCLUSIONS: A statistically significant reduction in the force necessary to remove posts cemented with zinc phosphate and glass ionomer cements occurred following application of ultrasound. The application of ultrasonic vibration did not influence the retention of cast posts cemented with resin cement.
Asunto(s)
Cementos Dentales , Retención de Prótesis Dentales , Técnica de Perno Muñón , Ultrasonido , Análisis de Varianza , Cementación , Aleaciones Dentales , Revestimiento para Colado Dental , Cementos Dentales/química , Desconsolidación Dental , Análisis del Estrés Dental/instrumentación , Cementos de Ionómero Vítreo/química , Humanos , Cementos de Resina/química , Estadística como Asunto , Estrés Mecánico , Propiedades de Superficie , Factores de Tiempo , Vibración , Cemento de Fosfato de Zinc/químicaRESUMEN
Os autores estudaram em tres grupos de recem-nascidos as possiveis relacoes entre a administracao de ocitocina em gestantes durante o trabalho de parto e/ou durante o parto e a hiperbilirrubinemia neonatal. No presente estudo com doses de oxitocina que variaram em torno de 5 UI, nao apareceram diferencas significativas entre as taxas de bilirrubina exibidas por esses recem-nascidos e aqueles cujas maes nao receberam esse tipo de tratamento (p > = 0,05)/