RESUMO
The current study aimed to evaluate the mechanical behavior of two different maxillary prosthetic rehabilitations according to the framework design using the Finite Element Analysis. An implant-supported full-arch fixed dental prosthesis was developed using a modeling software. Two conditions were modeled: a conventional casted framework and an experimental prosthesis with customized milled framework. The geometries of bone, prostheses, implants and abutments were modeled. The mechanical properties and friction coefficient for each isotropic and homogeneous material were simulated. A load of 100 N load was applied on the external surface of the prosthesis at 30° and the results were analyzed in terms of von Mises stress, microstrains and displacements. In the experimental design, a decrease of prosthesis displacement, bone strain and stresses in the metallic structures was observed, except for the abutment screw that showed a stress increase of 19.01%. The conventional design exhibited the highest stress values located on the prosthesis framework (29.65 MPa) between the anterior implants, in comparison with the experimental design (13.27 MPa in the same region). An alternative design of a stronger framework with lower stress concentration was reported. The current study represents an important step in the design and analysis of implant-supported full-arch fixed dental prosthesis with limited occlusal vertical dimension.
Assuntos
Prótese Dentária , Fenômenos Biomecânicos , Simulação por Computador , Análise de Elementos Finitos , Estresse MecânicoRESUMO
Os implantes osseointegrados promoveram importantes mudanças nas formas de reabilitação de pacientes parcial ou totalmente desdentados. Os pacientes totalmente desdentados apresentam clara predileção pelas próteses fixas implantossuportas, sobretudo porque proporcionam maior eficiência mastigatória e conforto, menos reparo e manutenção, além de favorecer o aspecto psicológico, uma vez que elimina o caráter removível das overdentures. Dentre os possíveis desenhos de próteses fixas as do tipo protocolo são as que apresentam maior aplicação clínica, e se caracterizam na mandíbula pela colocação de 4 a 6 implantes na região anterior, entre os forames mentuais, e cantilever distal bilateral para substituir os dentes posteriores. Na maxila recomenda-se a colocação de 6 a 8 implantes. Neste tipo de prótese utiliza-se uma infraestrutura metálica e uma base de resina para uni-la aos dentes de resina acrílica. O objetivo deste trabalho foi relatar um caso clínico de próteses totais fixas tipo protocolo bimaxilares, em que foram adotados critérios bem definidos de diagnóstico e planejamento, e empregadas técnicas cirúrgicas e protéticas com fundamentação científica.
The dental implants promoted important changes in the forms of rehabilitation of partially or fully edentulous patients. Edentulous patients show clear preference for implant-supported fixed prosthesis, mainly because they provide greater chewing efficiency and comfort, less repair and maintenance, in addition to promoting the psychological aspect, considering that eliminates the character removable of overdentures. Among the possible designs of the fixed prosthesis, the type protocols are the which have greater clinical application, and characterized by placing the jaw 4-6 implant in the anterior region between the foramina mentuals, and bilateral distal cantilevers to replace the posterior teeth. In the maxilla is recommended to put 6-8 implants. In this type of prosthesis is used a metal infrastructure and a resin base to attach it to the teeth of acrylic resin. The objective of this study was to report a case of protocol type full-arch fixed prosthesis bimaxillaries with employment of well-defined criteria for diagnosis and planning, and surgical and prosthetic techniques scientific evidence-based.