Sintering dental porcelain with CO2 laser: porosity and mechanical characterization
Autor(a) principal: | |
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Data de Publicação: | 2013 |
Outros Autores: | , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Brazilian Dental Science |
Texto Completo: | https://ojs.ict.unesp.br/index.php/cob/article/view/856 |
Resumo: | Aim: This work evaluated dental porcelain sintering by CO2 laser irradiation. Methods: Two commercial veneering porcelains were used: VM7 and VM9 (VITA Zahnfabrik). Porcelain disks (0.35 mm dia. x 2.0 mm) were sintered by a continuous CO2 laser (Coherent, USA – 35 W e ?= 10.6 ?m) in two irradiances (20 and 23 W/cm2) and exposure times: 5 and 10 min. A control group was sintered in a conventional oven following manufacturer’s instructions. After sintering, one of the disks surfaces was mirror polished. Superficial pores (%) were assessed by images obtained in an optical microscope (100x) submitted to the software Image J analysis. Apparent density was measured by Archimedean’s method. Microhardness and fracture toughness (Indentation Fracture - IF) were determined with a Vickers indenter (Shimadzu). Results: Porosity ranged between 4.0 and 5.9% for irradiated specimens; control group had 6.0 and 4.7% of porosity for porcelain VM7 and VM9 respectively. Density of porcelain VM7 irradiated for 10 min. with irradiance of 23 W/cm2 was significantly higher than control group. Microhardness and fracture toughness of irradiated specimens were similar to control. The measurements of some irradiated groups were not possible to achieve because the tests revealed irregular marks after indentation. Conclusions: Porcelain sintering with CO2 laser in some fluences produced a material with superficial porosity similar to that obtained in conventional oven. Microhardness and fracture toughness could not be measured for all irradiated groups suggesting some subsuperficial defect caused by entrapped gases or cracks originated by temperature gradient along the specimen. |
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oai:ojs.pkp.sfu.ca:article/856 |
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UNESP-20 |
network_name_str |
Brazilian Dental Science |
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Sintering dental porcelain with CO2 laser: porosity and mechanical characterizationAim: This work evaluated dental porcelain sintering by CO2 laser irradiation. Methods: Two commercial veneering porcelains were used: VM7 and VM9 (VITA Zahnfabrik). Porcelain disks (0.35 mm dia. x 2.0 mm) were sintered by a continuous CO2 laser (Coherent, USA – 35 W e ?= 10.6 ?m) in two irradiances (20 and 23 W/cm2) and exposure times: 5 and 10 min. A control group was sintered in a conventional oven following manufacturer’s instructions. After sintering, one of the disks surfaces was mirror polished. Superficial pores (%) were assessed by images obtained in an optical microscope (100x) submitted to the software Image J analysis. Apparent density was measured by Archimedean’s method. Microhardness and fracture toughness (Indentation Fracture - IF) were determined with a Vickers indenter (Shimadzu). Results: Porosity ranged between 4.0 and 5.9% for irradiated specimens; control group had 6.0 and 4.7% of porosity for porcelain VM7 and VM9 respectively. Density of porcelain VM7 irradiated for 10 min. with irradiance of 23 W/cm2 was significantly higher than control group. Microhardness and fracture toughness of irradiated specimens were similar to control. The measurements of some irradiated groups were not possible to achieve because the tests revealed irregular marks after indentation. Conclusions: Porcelain sintering with CO2 laser in some fluences produced a material with superficial porosity similar to that obtained in conventional oven. Microhardness and fracture toughness could not be measured for all irradiated groups suggesting some subsuperficial defect caused by entrapped gases or cracks originated by temperature gradient along the specimen.Institute of Science and Technology of São José dos Campos2013-03-28info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://ojs.ict.unesp.br/index.php/cob/article/view/85610.14295/bds.2013.v16i1.856Brazilian Dental Science; Vol. 16 No. 1 (2013): Jan. - Mar. / 2013 - Published March 2013; 46-52Brazilian Dental Science; v. 16 n. 1 (2013): Jan. - Mar. / 2013 - Published March 2013; 46-522178-6011reponame:Brazilian Dental Scienceinstname:Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP)instacron:UNESPenghttps://ojs.ict.unesp.br/index.php/cob/article/view/856/786Sgura, RicardoReis, Mariana CavalcanteAndreeta, Marcello Rubens BarsiHernandes, Antônio CarlosMedeiros, Igor Studartinfo:eu-repo/semantics/openAccess2020-01-28T12:37:49Zoai:ojs.pkp.sfu.ca:article/856Revistahttp://bds.ict.unesp.br/PUBhttp://ojs.fosjc.unesp.br/index.php/index/oaisergio@fosjc.unesp.br||sergio@fosjc.unesp.br2178-60112178-6011opendoar:2022-11-08T16:29:52.403067Brazilian Dental Science - Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP)true |
dc.title.none.fl_str_mv |
Sintering dental porcelain with CO2 laser: porosity and mechanical characterization |
title |
Sintering dental porcelain with CO2 laser: porosity and mechanical characterization |
spellingShingle |
Sintering dental porcelain with CO2 laser: porosity and mechanical characterization Sgura, Ricardo |
title_short |
Sintering dental porcelain with CO2 laser: porosity and mechanical characterization |
title_full |
Sintering dental porcelain with CO2 laser: porosity and mechanical characterization |
title_fullStr |
Sintering dental porcelain with CO2 laser: porosity and mechanical characterization |
title_full_unstemmed |
Sintering dental porcelain with CO2 laser: porosity and mechanical characterization |
title_sort |
Sintering dental porcelain with CO2 laser: porosity and mechanical characterization |
author |
Sgura, Ricardo |
author_facet |
Sgura, Ricardo Reis, Mariana Cavalcante Andreeta, Marcello Rubens Barsi Hernandes, Antônio Carlos Medeiros, Igor Studart |
author_role |
author |
author2 |
Reis, Mariana Cavalcante Andreeta, Marcello Rubens Barsi Hernandes, Antônio Carlos Medeiros, Igor Studart |
author2_role |
author author author author |
dc.contributor.author.fl_str_mv |
Sgura, Ricardo Reis, Mariana Cavalcante Andreeta, Marcello Rubens Barsi Hernandes, Antônio Carlos Medeiros, Igor Studart |
description |
Aim: This work evaluated dental porcelain sintering by CO2 laser irradiation. Methods: Two commercial veneering porcelains were used: VM7 and VM9 (VITA Zahnfabrik). Porcelain disks (0.35 mm dia. x 2.0 mm) were sintered by a continuous CO2 laser (Coherent, USA – 35 W e ?= 10.6 ?m) in two irradiances (20 and 23 W/cm2) and exposure times: 5 and 10 min. A control group was sintered in a conventional oven following manufacturer’s instructions. After sintering, one of the disks surfaces was mirror polished. Superficial pores (%) were assessed by images obtained in an optical microscope (100x) submitted to the software Image J analysis. Apparent density was measured by Archimedean’s method. Microhardness and fracture toughness (Indentation Fracture - IF) were determined with a Vickers indenter (Shimadzu). Results: Porosity ranged between 4.0 and 5.9% for irradiated specimens; control group had 6.0 and 4.7% of porosity for porcelain VM7 and VM9 respectively. Density of porcelain VM7 irradiated for 10 min. with irradiance of 23 W/cm2 was significantly higher than control group. Microhardness and fracture toughness of irradiated specimens were similar to control. The measurements of some irradiated groups were not possible to achieve because the tests revealed irregular marks after indentation. Conclusions: Porcelain sintering with CO2 laser in some fluences produced a material with superficial porosity similar to that obtained in conventional oven. Microhardness and fracture toughness could not be measured for all irradiated groups suggesting some subsuperficial defect caused by entrapped gases or cracks originated by temperature gradient along the specimen. |
publishDate |
2013 |
dc.date.none.fl_str_mv |
2013-03-28 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
https://ojs.ict.unesp.br/index.php/cob/article/view/856 10.14295/bds.2013.v16i1.856 |
url |
https://ojs.ict.unesp.br/index.php/cob/article/view/856 |
identifier_str_mv |
10.14295/bds.2013.v16i1.856 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
https://ojs.ict.unesp.br/index.php/cob/article/view/856/786 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Institute of Science and Technology of São José dos Campos |
publisher.none.fl_str_mv |
Institute of Science and Technology of São José dos Campos |
dc.source.none.fl_str_mv |
Brazilian Dental Science; Vol. 16 No. 1 (2013): Jan. - Mar. / 2013 - Published March 2013; 46-52 Brazilian Dental Science; v. 16 n. 1 (2013): Jan. - Mar. / 2013 - Published March 2013; 46-52 2178-6011 reponame:Brazilian Dental Science instname:Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Brazilian Dental Science |
collection |
Brazilian Dental Science |
repository.name.fl_str_mv |
Brazilian Dental Science - Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP) |
repository.mail.fl_str_mv |
sergio@fosjc.unesp.br||sergio@fosjc.unesp.br |
_version_ |
1788346898506055680 |