João Paulo Mendes Tribst1, Amanda Maria de Oliveira Dal Piva2, Alexandre Luiz Souto Borges3, Rodrigo Máximo Araújo4, João Maurício Ferraz da Silva5, Marco Antonio Bottino6, Cornelis Johannes Kleverlaan7, Niek de Jager8. 1. PhD Graduate Program in Restorative Dentistry, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, nº 777. Jardim São Dimas, 12245-000, São José dos Campos, SP, Brazil; Department of Dental Materials Science, Academic Center for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Gustav Mahlerlaan #3004, 1081 LA, Amsterdam, Noord-Holland, The Netherlands. Electronic address: joao.tribst@unesp.br. 2. PhD Graduate Program in Restorative Dentistry, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, nº 777. Jardim São Dimas, 12245-000, São José dos Campos, SP, Brazil; Department of Dental Materials Science, Academic Center for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Gustav Mahlerlaan #3004, 1081 LA, Amsterdam, Noord-Holland, The Netherlands. Electronic address: amanda.piva@unesp.br. 3. PhD Graduate Program in Restorative Dentistry, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, nº 777. Jardim São Dimas, 12245-000, São José dos Campos, SP, Brazil. Electronic address: alexandre.borges@unesp.br. 4. PhD Graduate Program in Restorative Dentistry, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, nº 777. Jardim São Dimas, 12245-000, São José dos Campos, SP, Brazil. Electronic address: maximo.araujo@unesp.br. 5. PhD Graduate Program in Restorative Dentistry, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, nº 777. Jardim São Dimas, 12245-000, São José dos Campos, SP, Brazil. Electronic address: joao.mauricio@unesp.br. 6. PhD Graduate Program in Restorative Dentistry, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, nº 777. Jardim São Dimas, 12245-000, São José dos Campos, SP, Brazil. Electronic address: mmbottino@uol.com.br. 7. Department of Dental Materials Science, Academic Center for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Gustav Mahlerlaan #3004, 1081 LA, Amsterdam, Noord-Holland, The Netherlands. Electronic address: c.kleverlaan@acta.nl. 8. Department of Dental Materials Science, Academic Center for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Gustav Mahlerlaan #3004, 1081 LA, Amsterdam, Noord-Holland, The Netherlands. Electronic address: n.d.jager@acta.nl.
Abstract
OBJECTIVES: This study aimed to evaluate the effect of different materials and undercut on the removal force and stress distribution in the supporting tooth and in the circumferential clasp used in removable partial prosthesis. METHODS: Upper molars prepared for Akers circumferential clasp with retention and opposing arm were modeled, scanned, elaborated with CAD software and the geometries imported in FEA and analyzed. Six different materials were selected for the clasp (Polyamide, Polyoxymethylene, Polyetheretherketone - PEEK, Gold alloy, Titanium and CoCr) and 3 different undercuts (0.25, 0.50 and 0.75mm), totaling 18 groups. RESULTS: The clasps presented greater stress in their structure and potentially greater damage to the dental enamel when made with rigid materials and with more undercut; however, they presented greater ability to remain in position. SIGNIFICANCE: Polyamide with a higher undercut is an esthetic alternative to rigid metallic clasps. It showed promising behavior because it strongly reduces the damage to the enamel, and even with an undercut of 0.75, the retention is lower than for CoCr with a 0.25 undercut, and this retention might still be sufficient. Polyoxymethylene and Polyetheretherketone (PEEK) are not suitable materials for the clasps, because the maximum stress occurring during removal with higher undercuts is higher than the material strength.
OBJECTIVES: This study aimed to evaluate the effect of different materials and undercut on the removal force and stress distribution in the supporting tooth and in the circumferential clasp used in removable partial prosthesis. METHODS: Upper molars prepared for Akers circumferential clasp with retention and opposing arm were modeled, scanned, elaborated with CAD software and the geometries imported in FEA and analyzed. Six different materials were selected for the clasp (Polyamide, Polyoxymethylene, Polyetheretherketone - PEEK, Gold alloy, Titanium and CoCr) and 3 different undercuts (0.25, 0.50 and 0.75mm), totaling 18 groups. RESULTS: The clasps presented greater stress in their structure and potentially greater damage to the dental enamel when made with rigid materials and with more undercut; however, they presented greater ability to remain in position. SIGNIFICANCE: Polyamide with a higher undercut is an esthetic alternative to rigid metallic clasps. It showed promising behavior because it strongly reduces the damage to the enamel, and even with an undercut of 0.75, the retention is lower than for CoCr with a 0.25 undercut, and this retention might still be sufficient. Polyoxymethylene and Polyetheretherketone (PEEK) are not suitable materials for the clasps, because the maximum stress occurring during removal with higher undercuts is higher than the material strength.
Authors: Ludan Qin; Shuo Yao; Jiaxin Zhao; Chuanjian Zhou; Thomas W Oates; Michael D Weir; Junling Wu; Hockin H K Xu Journal: Materials (Basel) Date: 2021-01-15 Impact factor: 3.623
Authors: Naseer Ahmed; Maria Shakoor Abbasi; Sara Haider; Nimra Ahmed; Syed Rashid Habib; Sara Altamash; Muhammad Sohail Zafar; Mohammad Khursheed Alam Journal: Biomed Res Int Date: 2021-09-06 Impact factor: 3.411
Authors: João Paulo Mendes Tribst; Dayana Campanelli de Morais; Jefferson David Melo de Matos; Guilherme da Rocha Scalzer Lopes; Amanda Maria de Oliveira Dal Piva; Alexandre Luiz Souto Borges; Marco Antonio Bottino; Antonio Lanzotti; Massimo Martorelli; Pietro Ausiello Journal: Dent J (Basel) Date: 2022-01-14