RESUMO

OBJECTIVE: Auricular prostheses are artificial substitutes for facial defects. The retention of these has often been a problem. This study aimed to evaluate the mechanical behavior of 3 retained auricular prosthetic connections when submitted to a mechanical cycling test. MATERIALS AND METHODS: Twelve samples with installed implants were obtained and divided into 3 groups according to their retention system with 4 samples in each group. I: bar-clip system; II: magnet system; and III: ball/o-ring system. Each of samples was submitted to the pull-out test during 3240 cycles (f = 0.5 Hz) to determine its tensile strength. The mechanical cycling test was performed using the servo-hydraulic machine MTS 810-Flex Test 40 (Eden Prairie, MN) that had a 2.5 mm shift at a 10 mm/s velocity. The retaining strength for each of the samples was obtained at 7 intervals. RESULTS: The tensile strength for the group retained by the bar-clip system (29.60 N) was higher with statistically significant difference (P < 0.05) when compared with the group retained by the ball/o-ring system (9.41 N) and magnets system (8.61 N) for all periods assessed. The ball/o-ring system showed loss of retention during the fatigue test (Kruskal-Wallis, chi-squared = 17.28; P < 0.01). CONCLUSIONS: The evaluated systems showed a tensile strength compatible with the clinical use and no fractures of the components were observed.

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RESUMO

Objetivou-se avaliar o conhecimento da rotina dos implantodontistas acerca das conexões das próteses sobre implantes, do torque necessário aos parafusos e recomendado pelos fabricantes, e orientar os profissionais quanto à rotina de calibração dos torquímetros. Foi aplicado um questionário assistido para coleta de informações sobre o conhecimento de implantodontistas atuantes em Goiânia/GO sobre as conexões protéticas, torque de parafusos e uso do torquímetro. Foram respondidos 22 questionários, que evidenciou um tempo médio de tempo de trabalho de 09 anos com as próteses sobre implantes. Houve uma tendência de uso das conexões de hexágono externo (HE) e cone morse (CM), sendo o CM preferido para casos unitários (63%) e o HE para próteses múltiplas (59%). A preferência dos respondentes foi pela prótese parafusada (86%) e o relato principal de falha foi de afrouxamento dos parafusos (81,8%). Apenas 31,8% dos respondentes se preocupam com a calibração dos torquímetros. Concluiu-se a tendência de uso das conexões de CM com relatos de conhecimento do torque requerido pelos parafusos, no entanto, sem a preocupação com a calibração rotineira do torquímetro (AU).

The aim of this study was to evaluate the knowledge of implantodontists about prosthetic implant connections, the required torque for the used screws, and on manufacturers' recommendation, as well as to guide professionals on the routine calibration of torque wrenches. A questionnaire was used to gather information on the knowledge of active implantodontists in Goiânia (GO-Brazil) about prosthetic connections, screws torque, and the use of torque wrench. Twenty two questionnaires were answered, and showed an average of 09 years of experience working with implant-supported prosthesis. There was a tendency to use the external connections hexagon (HE) and morse taper (CM), and the preferred CM for unit cases (63%) and HE for multiple prosthesis (59%). The preference of the respondents was the screwed prosthesis (86%) and the primary reporting failure was loosening the screws (81.8%). Only 31.8% of respondents are concerned about the calibration of torque wrenches. It was concluded the use trend of CM connections with knowledge of reports of the torque required by screws, however, without concern for the routine calibration of the torque wrench (AU).

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