Morse taper implants at different bone levels: a finite element analysis of stress distribution

Aim: To explore the biomechanical effects of the different implantation bone levels of Morse taper implants, employing a finite element analysis (FEA). Methods: Dental implants (TitamaxCM) with 4x13 mm and 4x11 mm, and their respective abutments with 3.5 mm height, simulating a screwed premolar metal-ceramic crown, had their design performed using the software AnsysWorkbench10.0. They were positioned in bone blocks, covered by 2.5 mm thickness of mucosa. The cortical bone was designed with 1.5 mm thickness and the trabecular bone completed the bone block. Four groups were formed: group 11CBL (11 mm implant length on cortical bonelevel), group 11TBL (11 mm implant length on trabecular bone level), group 13CBL (13mm implant length on cortical bone level) and group 13TBL (13 mm implant length on trabecular bonelevel). Oblique 200 N loads were applied. Von Mises equivalent stresses in cortical and trabecular bones were evaluated with the same design program. Results: The results were shown qualitatively and quantitatively by standard scales for each type of bone. By the results obtained, it can be suggested that positioning the implant completely in trabecular bone brings harm with respect to the generated stresses. Its implantation in the cortical bone has advantages with respect to better anchoring and locking, reflecting a better dissipation of the stresses along the implant/bone interfaces. In addition, the search for anchoring the implant in its apical region in cortical bone is of great value to improve stabilization and consequently better stress distribution.Conclusions: The implant position slightly below the bone in relation to the bone crest brings advantages as the best long-term predictability with respect to the expected neck bone loss.

Problemas na junção implante/prótese: uma alternativa para resolução do caso / Problems at the implant/prosthesis junction: an alternative for solving the case

A Implantodontia vem se destacando entre as diversas áreas da Odontologia moderna. As possibilidades de tratamento envolvendo os implantes dentários têm facilitado e ampliado a gama de opções ao cirurgião dentista. No entanto, a proposta de tratamento envolvendo reabilitação sobre implantes traz consigo problemas a serem solucionados, já que tal tratamento também é passível de intercorrências. A curva de aprendizagem com o emprego da Implantodontia deve ser respeitada, já que tanto na fase cirúrgica quanto na fase protética, existem critérios a serem respeitados para um bom prognóstico do tratamento. Além disso, quando surgem as intercorrências é imprescindível o preparo e conhecimento do profissional em questão. O presente caso clínico relata uma reabilitação unitária sobre implante, a qual necessitou ser realizada fora dos padrões normais da Implantodontia, já que foi constatada deformação na plataforma hexagonal do mesmo. É possível que tal ocorrência tenha sido causada na fase cirúrgica, durante a instalação do implante, devido a um provável torque excessivo, resultando na impossibilidade da adaptação dos componentes protéticos. A resolução do caso ocorreu com a instalação de um núcleo metálico fundido sobre o implante e confecção de prótese metalocerâmica cimentada. Com o presente relato, pode-se notar a importância do conhecimento de conceitos básicos por parte do cirurgião dentista, assim como sua flexibilidade frente às intercorrências do tratamento

The Implantology has become highlighted among the various areas of modern dentistry. The treatment possibilities involving dental implants have facilitated and expanded the range of options to the dentist. However, the treatment involving rehabilitation with implants can bring problems to be solved, as this treatment is also susceptible to complications. Learning curve with the use of implants should be respected, both in the surgical and prosthetic phases, because there are criteria to be met for a good treatment prognosis. Also, when complications occur, it is essential preparation and knowledge of the professional. This case report describes unit rehabilitation with implant, which needed to be performed outside of the normal standards of implant dentistry, as was observed deformation on the hexagonal platform. It is possible that it has been caused during implant installation surgery phase, due to an excessive torque, resulting in the inability to adapt the prosthetic components. The case resolution was with the installation of a cast metal core on the implant and making a metaloceramic cemented prosthesis. With this case report may be noted the importance of knowledge of basic concepts by the dentist, as well as its flexibility in the face of complications of treatment