Biomechanical behavior of atrophic maxillary restorations using the all-on-four concept and long trans-sinus implants: A finite element analysis

Abstract

Background. Maxillary bone atrophy with a considerable amount of pneumatization and anterior expansion of the maxillary sinus might be a situation limiting oral rehabilitation with osseointegrated implants. Therefore, the present study aimed to biomechanically evaluate two rehabilitation techniques for maxillary bone atrophy: all-on-four and long trans-sinus implants. Methods. Two three-dimensional models consisting of atrophic maxilla with four implants were simulated. In the M1 model, two axially inserted anterior implants and two tilted implants, 15 mm in length, placed tangential to the maxillary sinus’s anterior wall were used. In the M2 model, two axially inserted anterior implants and two trans-sinus tilted implants, 24 mm in length, were used. For the finite element analysis (FEA), an axial load of 100 N was applied on the entire extension of the prosthesis, simulating a rehabilitation with immediate loading. The peri-implant bone and the infrastructure were analyzed according to the Mohr-Coulomb and Rankine criteria, respectively. Results. The results were similar when the stresses on peri-implant bone were compared: 0.139 and 0.149 for models 1 and 2, respectively. The tension values were lower in the model with trans-sinus implants (27.99 MPa). Conclusion. It was concluded that the two techniques exhibited similar biomechanical behavior, suggesting that the use of long trans-sinus implants could be a new option for atrophic maxilla rehabilitation.

Assessment of Preload Loss after Cyclic Loading in the OT Bridge System in an “All-on-Four” Rehabilitation Model in the Absence of One and Two Prosthesis Screws

“…Abutments used for implant-supported prosthodontics have been largely studied, and nowadays the most used solutions are the screw-retained abutments. The use of this type of abutments and their mechanical complications, like the loss of preload and the fracture of prosthetic screws, are well known [31]. The stability of the OT Bridge system is provided by both the screw and the interlocking system between the acetalic Seeger in the extragrade abutment and the subequatorial region of the OT equator attachment.…”

“…The limits of this study are principally related to its in vitro nature because the resin model tested did not allow us to understand and determine the effect on soft and hard peri-implant tissues and the number of five unscrewing sessions per group resulted in a limited amount of data. The model used for this study was based on an edentulous lower arch, but for the upper jaws the results could be different because of the different circle arch described and the different implant angulations [22,31]. On the other hand, the bilateral forces exerted on the cantilever to simulate stressful conditions in the oral cavity may be unrealistic, because the chewing function foresees different loading conditions and is multidirectional, not vector-specific.…”

Reabilitação Cirúrgica De Maxilares Atróficos Através Da Técnica All-on-Four: Um Conceito De Tratamento

“…A utilização de implantes transinusais é uma alternativa para estes casos (CARVALHO et al, 2021). A técnica de ancoragem com implantes transinusais consiste em cruzar o implante através do seio maxilar após a elevação da membrana sinusal e estabilização na parede anterior do mesmo ou na parede da fossa nasal (JENSEN et al, 2012;CARVALHO et al, 2017).…”

“…(VASCO et al, 2014). Carvalho et al (2021) concluíram através de análise de elementos finitos que as duas técnicas exibiram comportamento biomecânico semelhante (com valores menores de estresse na prótese sobre implantes transinusais), sugerindo que o uso de implantes transinusais longos pode ser uma opção para a reabilitação de maxilas atróficas.…”

Os Biomateriais No Reparo Ósseo Em Odontologia

“…Fato corroborado e ratificado por Hassan e Emarah (2020), que excluíram de seu ensaio clínico randomizado, pacientes com discrasias sanguíneas, doenças autoimunes, diabetes mellitus não controlada, doenças ósseo-metabólicas, radioterapia de cabeça e pescoço (nos últimos 2 anos), hábitos de higiene bucal inadequados e tabagismo. (CARVALHO et al, 2021).…”