João Paulo Mendes Tribst1, Amanda Maria de Oliveira Dal Piva2, Camila Ferreira Leite Madruga3, Marcia Carneiro Valera4, Alexandre Luiz Souto Borges5, Eduardo Bresciani6, Renata Marques de Melo7. 1. Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, n° 777, Jardim São Dimas, 12245-000 São José dos Campos, SP, Brazil. Electronic address: joao.tribst@ict.unesp.br. 2. Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, n° 777, Jardim São Dimas, 12245-000 São José dos Campos, SP, Brazil. Electronic address: amanda.piva@ict.unesp.br. 3. Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, n° 777, Jardim São Dimas, 12245-000 São José dos Campos, SP, Brazil. Electronic address: camila.domingues@ict.unesp.br. 4. Department of Restorative Dentistry, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, n° 777, Jardim São Dimas, 12245-000 São José dos Campos, SP, Brazil. Electronic address: marcia@ict.unesp.br. 5. Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, n° 777, Jardim São Dimas, 12245-000 São José dos Campos, SP, Brazil. Electronic address: aleborges@ict.unesp.br. 6. Department of Restorative Dentistry, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, n° 777, Jardim São Dimas, 12245-000 São José dos Campos, SP, Brazil. Electronic address: eduardob@ict.unesp.br. 7. Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, n° 777, Jardim São Dimas, 12245-000 São José dos Campos, SP, Brazil. Electronic address: renata.marinho@ict.unesp.br.
Abstract
OBJECTIVE: The goal of this study was to evaluate the stress distribution in a tooth/restoration system according to the factors "amount of dental remnant" (3 levels) and "restorative material" (2 levels). METHODS: Three endodontically treated maxillary molars were modeled with CAD software for conducting non-linear finite element analysis (FEA), each with a determined amount of dental remnant of 1.5, 3, or 4.5mm. Models were duplicated, and half received restorations in lithium disilicate (IPS e.max CAD), while the other half received leucite ceramic restorations (IPS Empress CAD), both from Ivoclar Vivadent (Schaan, Liechtenstein). The solids were imported to analysis software (ANSYS 17.2, ANSYS Inc., Houston, TX, USA) in STEP format. All contacts involving the resin cement were considered no-separation, whereas between teeth and fixation cylinder, the contact was considered perfectly bonded. The mechanical properties of each structure were reported, and the materials were considered isotropic, linearly elastic, and homogeneous. An axial load (300N) was applied at the occlusal surface (triploidism area). Results were determined by colorimetric graphs of maximum principal stress (MPS) on tooth remnant, cement line, and restoration. RESULTS: MPS revealed that both factors influenced the stress distribution for all structures; the higher the material's elastic modulus, the higher the stress concentration on the restoration and the lower the stress concentration on the cement line. Moreover, the greater the dental crown remnant, the higher the stress concentration on the restoration. Thus, the remaining dental tissue should always be preserved. SIGNIFICANCE: In situations in which few dental remnants are available, the thicker the restoration, the higher the concentration of stresses in its structure, protecting the adhesive interface from potential adhesive failures. Results are more promising when the endocrown is fabricated with lithium disilicate ceramic.
OBJECTIVE: The goal of this study was to evaluate the stress distribution in a tooth/restoration system according to the factors "amount of dental remnant" (3 levels) and "restorative material" (2 levels). METHODS: Three endodontically treated maxillary molars were modeled with CAD software for conducting non-linear finite element analysis (FEA), each with a determined amount of dental remnant of 1.5, 3, or 4.5mm. Models were duplicated, and half received restorations in lithium disilicate (IPS e.max CAD), while the other half received leucite ceramic restorations (IPS Empress CAD), both from Ivoclar Vivadent (Schaan, Liechtenstein). The solids were imported to analysis software (ANSYS 17.2, ANSYS Inc., Houston, TX, USA) in STEP format. All contacts involving the resin cement were considered no-separation, whereas between teeth and fixation cylinder, the contact was considered perfectly bonded. The mechanical properties of each structure were reported, and the materials were considered isotropic, linearly elastic, and homogeneous. An axial load (300N) was applied at the occlusal surface (triploidism area). Results were determined by colorimetric graphs of maximum principal stress (MPS) on tooth remnant, cement line, and restoration. RESULTS:MPS revealed that both factors influenced the stress distribution for all structures; the higher the material's elastic modulus, the higher the stress concentration on the restoration and the lower the stress concentration on the cement line. Moreover, the greater the dental crown remnant, the higher the stress concentration on the restoration. Thus, the remaining dental tissue should always be preserved. SIGNIFICANCE: In situations in which few dental remnants are available, the thicker the restoration, the higher the concentration of stresses in its structure, protecting the adhesive interface from potential adhesive failures. Results are more promising when the endocrown is fabricated with lithium disilicate ceramic.
Authors: João Paulo Mendes Tribst; Amanda Maria de Oliveira Dal Piva; Roberto Lo Giudice; Alexandre Luiz Souto Borges; Marco Antonio Bottino; Ettore Epifania; Pietro Ausiello Journal: Int J Environ Res Public Health Date: 2020-06-05 Impact factor: 3.390
Authors: Gabriela Fernandes da Fonseca; Guilherme Schmitt de Andrade; Amanda Maria de Oliveira Dal Piva; João Paulo Mendes Tribst; Alexandre Luiz Souto Borges Journal: J Indian Prosthodont Soc Date: 2018 Oct-Dec