Liberdade rotacional em implantes dentários avaliada pelos métodos experimental e analítico

• Autor(a) principal: Davi, Letícia Resende
• Data de Publicação: 2006
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFU
• Texto Completo: https://repositorio.ufu.br/handle/123456789/16994
• topic: Implantes dentários osseointegrados; CNPQ::CIENCIAS DA SAUDE::ODONTOLOGIA

The aim of this study was to evaluate the integrity of the external hexagon of Internal Torque implants (IT Neodent Implante Osteointegrável), that despite of the external hexagon it uses internal hexagon to receive torque during surgical placement, comparing with external hexagon implants: conventional (External Hexagon, EH - Neodent Implante Osteointegrável) and Brånemark System MK III (Nobel Biocare, NO). Moreover, it was validated an analytical model of rotational freedom with experimental measurements. A device was made to measure rotational freedom angles between hexagons of implant and abutment for 10 intact samples of each group and after simulating surgical placement under torques of 45, 60 and 80 Ncm. The distance between the sides of the abutments internal hexagon had been measured for, together with the values of experimental rotational freedom, using the analytical model, with the aid of the program MATLAB. By means of this model it was possible to get the distances between the sides of the external hexagon of implants and thus to guide the measures in mono ocular optical microscope. Also, the distance between vertexes of the external hexagon were obtained for all intact samples. Again, the analytical model was used to get theoretical rotational freedom, in order to validate it. This sequence was repeated after each torque applied. Rotational freedom data were subjected to analysis of variance test (P<.05) showing no significant difference for the angles of intact EH and IT implants: EH 3.31±0.41° and IT 3.30±0.17°; and after 45 Ncm torque: EH 3.27±0.38° and IT 3.31±0.22°. Both were different from intact NO implants: 2.58±0.35°; and after 45 Ncm torque: 2.62±0.35°, that presented the lesser values. However, after 60 Ncm torque there were significant difference between the three types of implants: NO 2.67±0.34°, IT 3.40±0.20° and EH 4.03±0.54°. After 80 Ncm torque, there were significant difference between NO and IT implants, and the averages were 2.63±0.34° and 3.39±0.38°, respectively. The EH implants did not support this torque, deforming the external hexagon. The data of the distances between vertexes of the external hexagon were subjected to Mann-Whitney U test (P<.05) showing no significant difference for intact EH and IT implants, but both were different from NO implants, that presented the lesser values. After the torque of 60 Ncm, EH, IT and NO implants had presented equal statistical results. After the torque of 80 Ncm, IT and NO implants had not presented significant difference, but when comparing to EH implants both had presented difference, with EH implants presenting the lesser values. It could be concluded that IT and NO implants reacted better than EH implant after 60 and 80 Ncm torques in relation to the rotational freedom values. And still, the analytical model used in program MATLAB is valid to determine the theoretical rotational freedom angle of each sample after different levels of torque applied, without the need to realize measurements of rotational freedom in experimental device, being enough to get the distances between the sides of the hexagons of abutment and implants.