Influência de espessuras de fibromucosa e de material reembasador de próteses totais na distribuição de tensões sobre implantes cone morse durante fase de osseointegração: análise pelo método dos elementos finitos - 3D
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Data
2022-04-14
Autores
Araujo, Renan Ceolin [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Durante o período de osseointegração de implantes em uma reabilitação oral com prótese do tipo protocolo ou overdenture, uma prótese total convencional provisória poderá ser utilizada e revestida com materiais reembasadores macios, os quais têm por objetivo reduzir o estresse para a interface osso-implante. A avaliação mecânica de tal situação clínica é de extrema relevância, a fim de se estabelecer protocolos mais seguros durante esta fase inicial da implantodontia. O objetivo deste estudo foi realizar uma análise biomecânica pelo método dos elementos finitos 3D, da distribuição de tensões durante a fase provisória de reabilitação com implantes osseointegrados simulando uma situação clínica de protocolo/overdenture inferior sobre 4 implantes do tipo cone morse, na fase de cicatrização. Para este estudo foram confeccionados 6 modelos 3D, sob carregamento em 2 direções (vertical e oblíquo em relação ao plano oclusal), simulando osso tipo II, variando a altura do tecido gengival (2 mm e 3 mm) e a espessura do material reembasador (0 mm - sem material, 2 mm e 4 mm), sendo utilizado um cicatrizador compatível com a altura + 0,5 mm para cada situação gengival. A posição dos 4 implantes cone morse (UNITITE, UCM 3510N, SIN) foi sempre a mesma, nas posições perdidas dos dentes 46, 43, 33 e 36. Para a altura gengival de 2 mm foi utilizado cicatrizador de 2,5 mm de altura (UNITITE, CIMU 4525, SIN) e para a altura gengival de 3 mm, o cicatrizador de 3,5 mm de altura (UNITITE, CIMU 4535, SIN). Os modelos utilizados foram: (G2C2,5-SR) altura gengival de 2mm, cicatrizador de 2,5mm, sem material reembasador; (G2C2,5-R2) altura gengival de 2mm, cicatrizador de 2,5mm, com soft rreembasador de 2mm; (G2C2,5-R4) altura gengival de 2mm, cicatrizador de 2,5mm, com material reembasador de 4mm; (G3C3,5-SR) altura gengival de 3mm, cicatrizador de 3,5mm, sem material reembasador; (G3C3,5-R2) altura gengival de 3mm, cicatrizador de 3,5mm, e reembasador de 2mm e (G3C3,5-R4) altura gengival de 3mm, cicatrizador de 3,5mm e soft reembasador de 4mm. A metodologia para modelagem se baseou em um escaneamento de superfície de uma prótese total inferior montada, sob um modelo inferior padrão, e de seu modelo de assentamento. As geometrias dos implantes (CM 3,5x10mm) e de seus cicatrizadores foram obtidas por simplificação do desenho dos mesmos no programa SolidWorks e no programa Rhinoceros 3D. O software utilizado para análise foi o ANSYS 17.0. A visualização dos resultados foi qualitativa através de mapas de deslocamento, von Mises e tensão máxima principal. As regiões com maiores deslocamentos foram as dos implantes mais anteriores (#33 e #43), sendo os do modelo 6 submetidos a forças verticais os que apresentaram maiores deslocamentos, próximos a 0,05 mm. A força oblíqua, de forma geral, tendeu a sobrecarregar mais os implantes do lado onde as cargas foram aplicadas. No tecido ósseo foi possível observar que o osso cortical se mostrou com mais concentração de tensão de tração que o osso trabecular. A utilização do material reembasador gerou menores tensões transmitidas para o tecido gengival, concentrando estas tensões principalmente no material reembasador. A não utilização de material reembasador aumenta as concentrações de tensões nos implantes/cicatrizadores, independentemente de sua espessura ou da espessura gengival. Concluiu-se que o uso de reembasador soft diminuiu as tensões nos implantes/cicatrizadores e tecido gengival; o aumento da espessura do material reembasador não influenciou na diminuição das tensões aos tecidos de suporte e tecidos gengivais mais espessos foram favoráveis em diminuir as tensões transmitidas ao tecido ósseo, mas concentram mais tensões nos implantes/cicatrizadores.
During the period of osseointegration of implants in an oral rehabilitation with a protocol or overdenturetype prosthesis, a conventional temporary complete denture can be used and coated with soft reline materials, which aim to reduce the stress to the bone-implant interface. The mechanical assessment of such a clinical situation is extremely relevant in order to establish safer protocols during this initial phase of implantology. The objective of this study was to perform a biomechanical analysis by the 3D finite element method, of the stress distribution during the provisional phase of rehabilitation with osseointegrated implants simulating a clinical situation of protocol/lower overdenture on 4 cone morse implants, in the healing phase. For this study, 6 3D models were made, under loading in 2 directions (vertical and oblique in relation to the occlusal plane), simulating type II bone, varying the height of the gingival tissue (2 mm and 3 mm) and the thickness of the reline material (0 mm - without material, 2 mm and 4 mm), using a healer compatible with the height + 0.5 mm for each gingival situation. The position of the 4 cone morse implants (UNITITE, UCM 3510N, SIN) was always the same, in the missing positions of teeth 46, 43, 33 and 36. For the 2 mm gingival height, a 2.5 mm high healer was used. (UNITITE, CIMU 4525, SIN) and for a gingival height of 3 mm, the healer with a height of 3.5 mm (UNITITE, CIMU 4535, SIN). The models used were: (G2H2,5-WS) 2mm gingival height, 2.5mm healing, without soft material; (G2H2,5-S2) 2mm gingival height, 2.5mm healing, with 2mm reline; (G2H2,5-S4) 2mm gingival height, 2.5mm healing, with 4mm reline; (G3H3,5-WS) gingival height of 3mm, healing of 3.5mm, without soft material; (G3H3,5-S2) 3mm gingival height, 3.5mm healing, and 2mm reline and (G3H3,5-S4) gingival height of 3mm, healing of 3.5mm and reliner of 4mm. The methodology for modeling was based on a surface scan of a complete lower denture assembled, under a standard lower model, and its seating model. The geometries of the implants (CM 3.5x10mm) and their healers were obtained by simplifying their design in the SolidWorks program and in the Rhinoceros 3D program. The software used for analysis was ANSYS 17.0. The visualization of the results was qualitative through displacement maps, von Mises and maximum principal stress. The regions with the greatest displacements were those of the most anterior implants (#33 and #43), and those of model 6 submitted to vertical forces presented the greatest displacements, close to 0.05 mm. The oblique force, in general, tended to place more stress on the implants on the side where the loads were applied. In the bone tissue, it was possible to observe that the cortical bone showed a higher concentration of tensile stress than the trabecular bone. The use of soft material generated lower tensions transmitted to the gingival tissue, concentrating these tensions mainly in the soft material. The non-use of soft material increases stress concentrations on implants/healers, regardless of their thickness or gingival thickness. It was concluded that the use of a soft reliner reduced the stresses on the implants/healers and gingival tissue; the increase in the thickness of the reline material did not influence the reduction of tensions to the supporting tissues and thicker gingival tissues were favorable in reducing the tensions transmitted to the bone tissue, but concentrated more tensions in the implants/healing agents.
During the period of osseointegration of implants in an oral rehabilitation with a protocol or overdenturetype prosthesis, a conventional temporary complete denture can be used and coated with soft reline materials, which aim to reduce the stress to the bone-implant interface. The mechanical assessment of such a clinical situation is extremely relevant in order to establish safer protocols during this initial phase of implantology. The objective of this study was to perform a biomechanical analysis by the 3D finite element method, of the stress distribution during the provisional phase of rehabilitation with osseointegrated implants simulating a clinical situation of protocol/lower overdenture on 4 cone morse implants, in the healing phase. For this study, 6 3D models were made, under loading in 2 directions (vertical and oblique in relation to the occlusal plane), simulating type II bone, varying the height of the gingival tissue (2 mm and 3 mm) and the thickness of the reline material (0 mm - without material, 2 mm and 4 mm), using a healer compatible with the height + 0.5 mm for each gingival situation. The position of the 4 cone morse implants (UNITITE, UCM 3510N, SIN) was always the same, in the missing positions of teeth 46, 43, 33 and 36. For the 2 mm gingival height, a 2.5 mm high healer was used. (UNITITE, CIMU 4525, SIN) and for a gingival height of 3 mm, the healer with a height of 3.5 mm (UNITITE, CIMU 4535, SIN). The models used were: (G2H2,5-WS) 2mm gingival height, 2.5mm healing, without soft material; (G2H2,5-S2) 2mm gingival height, 2.5mm healing, with 2mm reline; (G2H2,5-S4) 2mm gingival height, 2.5mm healing, with 4mm reline; (G3H3,5-WS) gingival height of 3mm, healing of 3.5mm, without soft material; (G3H3,5-S2) 3mm gingival height, 3.5mm healing, and 2mm reline and (G3H3,5-S4) gingival height of 3mm, healing of 3.5mm and reliner of 4mm. The methodology for modeling was based on a surface scan of a complete lower denture assembled, under a standard lower model, and its seating model. The geometries of the implants (CM 3.5x10mm) and their healers were obtained by simplifying their design in the SolidWorks program and in the Rhinoceros 3D program. The software used for analysis was ANSYS 17.0. The visualization of the results was qualitative through displacement maps, von Mises and maximum principal stress. The regions with the greatest displacements were those of the most anterior implants (#33 and #43), and those of model 6 submitted to vertical forces presented the greatest displacements, close to 0.05 mm. The oblique force, in general, tended to place more stress on the implants on the side where the loads were applied. In the bone tissue, it was possible to observe that the cortical bone showed a higher concentration of tensile stress than the trabecular bone. The use of soft material generated lower tensions transmitted to the gingival tissue, concentrating these tensions mainly in the soft material. The non-use of soft material increases stress concentrations on implants/healers, regardless of their thickness or gingival thickness. It was concluded that the use of a soft reliner reduced the stresses on the implants/healers and gingival tissue; the increase in the thickness of the reline material did not influence the reduction of tensions to the supporting tissues and thicker gingival tissues were favorable in reducing the tensions transmitted to the bone tissue, but concentrated more tensions in the implants/healing agents.
Descrição
Palavras-chave
Implantes dentários, Prótese total, Reembasamento de dentadura, Fenômenos biomecânicos, Análise de elementos finitos, Dental Implants