Résumé
OBJECTIVES: To evaluate and compare the magnitude and distribution of stresses generated on implants, abutments and first molar metal-ceramic crowns using finite element analysis. METHODS: Preliminary three-dimensional models were created using the computer-aided design software SolidWorks. Stress and strain values were observed for two distinct virtual models: model 1 - Morse taper and solid abutment; model 2 - Morse taper and abutment with screw. A load (250 N) was applied to a single point of the occlusal surface at 15° to the implant long axis. Von Mises stresses were recorded for both groups at four main points: 1) abutment-retaining screws; 2) abutment neck; 3) cervical bone area; 4) implant neck. RESULTS AND CONCLUSION: Model 1 showed a higher stress value (1477.5 MPa) at the abutment-retaining screw area than the stresses found in model 2 (1091.1 MPa for the same area). The cervical bone strain values did not exceed 105 µm for either model.
Sujets)
Humains , Implants dentaires , Conception de prothèse dentaire/instrumentation , Analyse des éléments finis , Analyse du stress dentaire , Conception d'implant dentaire et de pilier/instrumentation , Contrainte mécanique , Conception de prothèse dentaire/méthodes , Conception assistée par ordinateur , Couronnes , Module d'élasticité , Conception d'implant dentaire et de pilier/méthodes , Mandibule/imagerie diagnostique , Modèles anatomiquesRésumé
Os implantes dentários tornaram-se uma realidade na reabilitação bucal, e grandes avanços como as conexões cone morse são utilizados com sucesso na reposição de dentes, diminuindo drasticamente o número de problemas como afrouxamento de parafusos. Por outro lado, a literatura mostra que o íntimo contato da interface implante/intermediário permite que tensões sejam distribuídas diretamente ao osso adjacente e às estruturas a ele conectadas, sendo que tensões acima dos limites de tolerância podem gerar microdanos e reabsorção óssea. O objetivo deste trabalho foi realizar uma revisão de literatura em bases de dados e livros sobre a distribuição das tensões nas interfaces implante/pilar e osso/implante, através de estudos de elementos finitos. Concluiu-se pelos estudos revisados, que a influência da morfologia anatômica do local, a angulação do implante, o tipo de material dos parafusos retentores e as condições de carregamento biomecânico do sistema osso-implante são diretamente proporcionais à resposta do tecido ósseo circunjacente ao implante
Dental implants have become a reality in oral rehabilitation, and major advances such as morse taper connections are successfully used in the replacement of missing teeth, reducing considerably the number of problems such as screw loosening. However, literature shows that the contact of implant/abutment interface distributes the stress directly to the adjacent bone, whereas stresses above the tolerance limits can generate microdamage and bone resorption. The objective of this study was to perform a literature review in databases and books about the distribution of stresses in implant/pillar and implant/bone interfaces through finite element analysis. It was concluded that the influence of anatomic morphology of the site, the angulation of the implant, the type of material of the retainer screws and biomechanical loading conditions of the bone-implant system are directly proportional to the response of the bone tissue surrounding the implant.