Marginal misfit of heat-pressed milled wax-pattern and CAD/CAM crowns and its effect on stress distribution in implant-supported rehabilitations
Braz. j. oral sci
; 20: e214873, jan.-dez. 2021. ilus
Article
em En
| BBO, LILACS
| ID: biblio-1254742
Biblioteca responsável:
BR218.1
ABSTRACT
Aim:
To compare the marginal fit of lithium disilicate CAD/CAM crowns and heat-pressed crowns fabricated using milled wax patterns, and evaluate its effect on stress distribution in implantsupported rehabilitation.Methods:
A CAD model of a mandibular first molar was designed, and 16 lithium disilicate crowns (8/group) were obtained. The crown-prosthetic abutment set was evaluated in a scanning electron microscopy. The mean misfit for each group was recorded and evaluated using Student's t-test. For in silico analysis, a virtual cement thickness was designed for the two misfit values found previously, and the CAD model was assembled on an implant-abutment set. A load of 100 N was applied at 30° on the central fossa, and the equivalent stress was calculated for the crown, titanium components, bone, and resin cement layer.Results:
The CAD/CAM group presented a significantly (p=0.0068) higher misfit (64.99±18.73 µm) than the heat-pressed group (37.64±15.66 µm). In silico results showed that the heat-pressed group presented a decrease in stress concentration of 61% in the crown and 21% in the cement. In addition, a decrease of 14.5% and an increase of 7.8% in the stress for the prosthetic abutment and implant, respectively, was recorded. For the cortical and cancellous bone, a slight increase in stress occurred with an increase in the cement layer thickness of 5.9% and 5.7%, respectively.Conclusion:
The milling of wax patterns for subsequent inclusion and obtaining heat-pressed crowns is an option to obtain restorations with an excellent marginal fit and better stress distribution throughout the implant-abutment setPalavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
BBO
/
LILACS
Assunto principal:
Microscopia Eletrônica de Varredura
/
Desenho Assistido por Computador
/
Adaptação Marginal Dentária
/
Prótese Dentária Fixada por Implante
/
Análise de Elementos Finitos
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Materiais Dentários
Idioma:
En
Revista:
Braz. j. oral sci
Assunto da revista:
ODONTOLOGIA
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Brasil