study of thermal degradation of the guta percha(1,4-trans-polyisoprene)and guta-percha cones used in root canal filling

Detalhes bibliográficos
Autor(a) principal: JoÃo Batista AraÃjo da Silva JÃnior
Data de Publicação: 2007
Tipo de documento: Tese
Idioma: por
Título da fonte: Biblioteca Digital de Teses e Dissertações da UFC
Texto Completo: http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=1391
Resumo: Gutta-percha cones are the most widely used material for root canal filling. They are composed of gutta-percha rubber (trans 1,4-polyisoprene), ZnO, BaSO4 and wax or resins. Gel permeation chromatography (GPC), Infrared spectroscopy (IR), nuclear magnetic resonance (NMR), atomic absorption spectroscopy and thermogravimetric analysis were used in the characterization of purified gutta-percha polymer and in the study of the in vitro and in vivo aging. The in vitro thermal degradation of purified gutta-percha polymer was monitored by IR spectroscopy. The increase of bands due to hydroxyl (OH; 3430-3440 cm-1) and carbonyl groups (C=O; 1720-1730 cm-1) were detected, probably due to products of degradation such as alcohols, carboxylic acid, hydroperoxide, aldehyde, ketone, ether or ester. A decrease on the band at 840 cm-1 due to =C-H was also detected. The effect of some components of cones (ZnO, BaSO4 and wax) in the in vitro thermal oxidation of gutta-percha polymer was carried out by IR spectroscopy through the evolution of hydroxyl band, carbonyl band and the decrease of =C-H band, assumed as related to the cleavage of isoprene double bond. The induction time (ti) and the apparent rate constants during early step of degradation were determined. The ti values for gutta-percha polymer was smaller than the observed for natural rubber (cis-isomer). Addition of ZnO to the gutta-percha anticipated the beginning of film degradation, while the addition of BaSO4 delayed it. Wax addition did not change the nduction time. The in vivo aging process of gutta-percha cones was monitored by GPC after the extraction of remaining cones during the retreatment followed by the polymer isolation. The molar mass of polyisoprene decreased with time, but in a slow rate. In tooth with caries and periodontal fection, the decrease in molar mass was higher than in healthy root canal. IR analysis of the in vivo aged gutta-percha showed the production of carbonyl and hydroxyl groups indicating that the process is oxidative. 1H-NMR analysis confirmed the formation of hydroperoxide during in vivo aging. It was also observed that the ZnO content in the cones decreases with increasing of aging time, due the contact with tissue fluids. Experiment with non aged cones in contact with artificial saliva and water also showed the decrease of cone mass with time due to the release of ZnO. Eight brands of gutta-percha cones available in Brazil were also characterized. The average composition was similar to other brands investigated. Differential scanning calorimetric study showed that gutta-percha polymer possess two crystalline phases (a and b). The changes in crystalline phase occur during thermal heating.
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spelling info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisstudy of thermal degradation of the guta percha(1,4-trans-polyisoprene)and guta-percha cones used in root canal fillingEstudo da degradaÃÃo tÃrmica da guta-percha (1,4-trans-polisopreno) e de cones de guta-percha utilizados em endodontia2007-09-04Regina CÃlia Monteiro de Paula31621252434http://lattes.cnpq.br/5685898279302235Alexandre Augusto Zaia16065108863 http://lattes.cnpq.br/7043320312245543Regina CÃlia Reis Nunes34947906715 http://lattes.cnpq.br/0865315341741765Judith Pessoa de Andrade Feitosa04522036353http://lattes.cnpq.br/5607366782144472Luiz Gonzaga de FranÃa Lopes5970092045378897050344http://lattes.cnpq.br/1757782029577937JoÃo Batista AraÃjo da Silva JÃniorUniversidade Federal do CearÃPrograma de PÃs-GraduaÃÃo em QuÃmica InorgÃnicaUFCBRguta-perchainfra-red raysthermoanalysis conesguta-perchainfravermelhotermoanaliseconesQUIMICAGutta-percha cones are the most widely used material for root canal filling. They are composed of gutta-percha rubber (trans 1,4-polyisoprene), ZnO, BaSO4 and wax or resins. Gel permeation chromatography (GPC), Infrared spectroscopy (IR), nuclear magnetic resonance (NMR), atomic absorption spectroscopy and thermogravimetric analysis were used in the characterization of purified gutta-percha polymer and in the study of the in vitro and in vivo aging. The in vitro thermal degradation of purified gutta-percha polymer was monitored by IR spectroscopy. The increase of bands due to hydroxyl (OH; 3430-3440 cm-1) and carbonyl groups (C=O; 1720-1730 cm-1) were detected, probably due to products of degradation such as alcohols, carboxylic acid, hydroperoxide, aldehyde, ketone, ether or ester. A decrease on the band at 840 cm-1 due to =C-H was also detected. The effect of some components of cones (ZnO, BaSO4 and wax) in the in vitro thermal oxidation of gutta-percha polymer was carried out by IR spectroscopy through the evolution of hydroxyl band, carbonyl band and the decrease of =C-H band, assumed as related to the cleavage of isoprene double bond. The induction time (ti) and the apparent rate constants during early step of degradation were determined. The ti values for gutta-percha polymer was smaller than the observed for natural rubber (cis-isomer). Addition of ZnO to the gutta-percha anticipated the beginning of film degradation, while the addition of BaSO4 delayed it. Wax addition did not change the nduction time. The in vivo aging process of gutta-percha cones was monitored by GPC after the extraction of remaining cones during the retreatment followed by the polymer isolation. The molar mass of polyisoprene decreased with time, but in a slow rate. In tooth with caries and periodontal fection, the decrease in molar mass was higher than in healthy root canal. IR analysis of the in vivo aged gutta-percha showed the production of carbonyl and hydroxyl groups indicating that the process is oxidative. 1H-NMR analysis confirmed the formation of hydroperoxide during in vivo aging. It was also observed that the ZnO content in the cones decreases with increasing of aging time, due the contact with tissue fluids. Experiment with non aged cones in contact with artificial saliva and water also showed the decrease of cone mass with time due to the release of ZnO. Eight brands of gutta-percha cones available in Brazil were also characterized. The average composition was similar to other brands investigated. Differential scanning calorimetric study showed that gutta-percha polymer possess two crystalline phases (a and b). The changes in crystalline phase occur during thermal heating. Cones de guta-percha sÃo os materiais mais utilizados para obturaÃÃo de canais em endodontia. Eles sÃo compostos de borracha de guta-percha (trans 1,4-poliisopreno), ZnO, BaSO4 e graxas ou resinas. Cromatografia de permeaÃÃo em gel (GPC), espectroscopia na regiÃo de infravermelho (IV), ressonÃncia magnÃtica nuclear (RMN), espectroscopia de absorÃÃo atÃmica e anÃlise termogravimÃtrica foram usadas na caracterizaÃÃo do polÃmero purificado e no estudo do envelhecimento in vitro e in vivo da guta-percha. A degradaÃÃo tÃrmica in vitro do polÃmero guta-percha purificado foi monitorado por espectroscopia de IV. O aumento das bandas devido a grupos hidroxilas (OH; 3430-3440 cm-1) e carbonilas (C=O; 1720-1730 cm-1) foram detectados, provavelmente devido a produtos de degradaÃÃo tais como Ãlcoois, Ãcidos carboxilicos, hidroperÃxidos, aldeidos, cetonas, Ãteres e Ãsteres. Um decrÃscimo na banda de 840 cm-1 devido à quebra =C-H tambÃm foi detectado. O efeito de alguns componentes dos cones (ZnO, BaSO4 e graxas) na oxidaÃÃo tÃrmica in vitro do polÃmero guta-percha foi analisado por espectroscopia IV com a evoluÃÃo das bandas de hidroxila, bandas de carbonila e decrÃscimo da banda de =C-H, assumindo como quebra da ligaÃÃo dupla do isopreno. O tempo de induÃÃo (ti) e as constantes aparentes de velocidade para a degradaÃÃo foram determinados. Os valores de ti para o polÃmero guta-percha foram menores do que o observado para a borracha natural (isÃmero-cis). A adiÃÃo de ZnO ao filme de guta-percha antecipa o inÃcio da degradaÃÃo, enquanto a adiÃÃo de BaSO4 o retarda. A adiÃÃo de cera nÃo mudou o tempo de induÃÃo. O processo de envelhecimento in vivo do cone guta-percha foi monitorado por GPC apÃs a extraÃÃo dos cones durante o retratamento seguido pela separaÃÃo do polÃmero remanescente. A massa molar do poliisopreno decresce com o tempo, mas em uma taxa lenta. No dente com cÃrie e infecÃÃo periapical, a diminuiÃÃo na massa molar foi mais elevada do que no dente de raiz saudÃvel. As anÃlises de IV no envelhecimento in vivo da guta-percha mostrou a produÃÃo de grupos carbonilas e hidroxilas indicando que o processo à oxidativo. As anÃlises 1H-RMN confirmaram a formaÃÃo de hidriperÃxidos durante o envelhecimento in vivo. Observou-se tambÃm que ZnO contidos nos cones diminui com o tempo de envelhecimento, devido ao contato com fluidos tissulares. Experimentos com cones nÃo envelhecidos em contato com saliva artificial e Ãgua tambÃm mostraram a diminuiÃÃo da massa do cone com o tempo devido a liberaÃÃo de ZnO. Oito marcas de cones de guta-percha disponÃveis no Brasil foram tambÃm caracterizadas. A composiÃÃo mÃdia foi similar a outras marcas investigadas. O estudo de calorimetria exploratÃria diferencial (DSC) mostrou que o polÃmero guta-percha possui duas fases cristalinas (a e b). As mudanÃas na fase cristalina ocorrem durante o aquecimento tÃrmico. FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgicohttp://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=1391application/pdfinfo:eu-repo/semantics/openAccessporreponame:Biblioteca Digital de Teses e Dissertações da UFCinstname:Universidade Federal do Cearáinstacron:UFC2019-01-21T11:14:19Zmail@mail.com -
dc.title.en.fl_str_mv study of thermal degradation of the guta percha(1,4-trans-polyisoprene)and guta-percha cones used in root canal filling
dc.title.alternative.pt.fl_str_mv Estudo da degradaÃÃo tÃrmica da guta-percha (1,4-trans-polisopreno) e de cones de guta-percha utilizados em endodontia
title study of thermal degradation of the guta percha(1,4-trans-polyisoprene)and guta-percha cones used in root canal filling
spellingShingle study of thermal degradation of the guta percha(1,4-trans-polyisoprene)and guta-percha cones used in root canal filling
JoÃo Batista AraÃjo da Silva JÃnior
guta-percha
infravermelho
termoanalise
cones
QUIMICA
title_short study of thermal degradation of the guta percha(1,4-trans-polyisoprene)and guta-percha cones used in root canal filling
title_full study of thermal degradation of the guta percha(1,4-trans-polyisoprene)and guta-percha cones used in root canal filling
title_fullStr study of thermal degradation of the guta percha(1,4-trans-polyisoprene)and guta-percha cones used in root canal filling
title_full_unstemmed study of thermal degradation of the guta percha(1,4-trans-polyisoprene)and guta-percha cones used in root canal filling
title_sort study of thermal degradation of the guta percha(1,4-trans-polyisoprene)and guta-percha cones used in root canal filling
author JoÃo Batista AraÃjo da Silva JÃnior
author_facet JoÃo Batista AraÃjo da Silva JÃnior
author_role author
dc.contributor.advisor1.fl_str_mv Regina CÃlia Monteiro de Paula
dc.contributor.advisor1ID.fl_str_mv 31621252434
dc.contributor.advisor1Lattes.fl_str_mv http://lattes.cnpq.br/5685898279302235
dc.contributor.referee1.fl_str_mv Alexandre Augusto Zaia
dc.contributor.referee1ID.fl_str_mv 16065108863
dc.contributor.referee1Lattes.fl_str_mv http://lattes.cnpq.br/7043320312245543
dc.contributor.referee2.fl_str_mv Regina CÃlia Reis Nunes
dc.contributor.referee2ID.fl_str_mv 34947906715
dc.contributor.referee2Lattes.fl_str_mv http://lattes.cnpq.br/0865315341741765
dc.contributor.referee3.fl_str_mv Judith Pessoa de Andrade Feitosa
dc.contributor.referee3ID.fl_str_mv 04522036353
dc.contributor.referee3Lattes.fl_str_mv http://lattes.cnpq.br/5607366782144472
dc.contributor.referee4.fl_str_mv Luiz Gonzaga de FranÃa Lopes
dc.contributor.referee4ID.fl_str_mv 59700920453
dc.contributor.authorID.fl_str_mv 78897050344
dc.contributor.authorLattes.fl_str_mv http://lattes.cnpq.br/1757782029577937
dc.contributor.author.fl_str_mv JoÃo Batista AraÃjo da Silva JÃnior
contributor_str_mv Regina CÃlia Monteiro de Paula
Alexandre Augusto Zaia
Regina CÃlia Reis Nunes
Judith Pessoa de Andrade Feitosa
Luiz Gonzaga de FranÃa Lopes
dc.subject.por.fl_str_mv guta-percha
infravermelho
termoanalise
cones
topic guta-percha
infravermelho
termoanalise
cones
QUIMICA
dc.subject.cnpq.fl_str_mv QUIMICA
dc.description.sponsorship.fl_txt_mv FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico
dc.description.abstract.por.fl_txt_mv Gutta-percha cones are the most widely used material for root canal filling. They are composed of gutta-percha rubber (trans 1,4-polyisoprene), ZnO, BaSO4 and wax or resins. Gel permeation chromatography (GPC), Infrared spectroscopy (IR), nuclear magnetic resonance (NMR), atomic absorption spectroscopy and thermogravimetric analysis were used in the characterization of purified gutta-percha polymer and in the study of the in vitro and in vivo aging. The in vitro thermal degradation of purified gutta-percha polymer was monitored by IR spectroscopy. The increase of bands due to hydroxyl (OH; 3430-3440 cm-1) and carbonyl groups (C=O; 1720-1730 cm-1) were detected, probably due to products of degradation such as alcohols, carboxylic acid, hydroperoxide, aldehyde, ketone, ether or ester. A decrease on the band at 840 cm-1 due to =C-H was also detected. The effect of some components of cones (ZnO, BaSO4 and wax) in the in vitro thermal oxidation of gutta-percha polymer was carried out by IR spectroscopy through the evolution of hydroxyl band, carbonyl band and the decrease of =C-H band, assumed as related to the cleavage of isoprene double bond. The induction time (ti) and the apparent rate constants during early step of degradation were determined. The ti values for gutta-percha polymer was smaller than the observed for natural rubber (cis-isomer). Addition of ZnO to the gutta-percha anticipated the beginning of film degradation, while the addition of BaSO4 delayed it. Wax addition did not change the nduction time. The in vivo aging process of gutta-percha cones was monitored by GPC after the extraction of remaining cones during the retreatment followed by the polymer isolation. The molar mass of polyisoprene decreased with time, but in a slow rate. In tooth with caries and periodontal fection, the decrease in molar mass was higher than in healthy root canal. IR analysis of the in vivo aged gutta-percha showed the production of carbonyl and hydroxyl groups indicating that the process is oxidative. 1H-NMR analysis confirmed the formation of hydroperoxide during in vivo aging. It was also observed that the ZnO content in the cones decreases with increasing of aging time, due the contact with tissue fluids. Experiment with non aged cones in contact with artificial saliva and water also showed the decrease of cone mass with time due to the release of ZnO. Eight brands of gutta-percha cones available in Brazil were also characterized. The average composition was similar to other brands investigated. Differential scanning calorimetric study showed that gutta-percha polymer possess two crystalline phases (a and b). The changes in crystalline phase occur during thermal heating.
Cones de guta-percha sÃo os materiais mais utilizados para obturaÃÃo de canais em endodontia. Eles sÃo compostos de borracha de guta-percha (trans 1,4-poliisopreno), ZnO, BaSO4 e graxas ou resinas. Cromatografia de permeaÃÃo em gel (GPC), espectroscopia na regiÃo de infravermelho (IV), ressonÃncia magnÃtica nuclear (RMN), espectroscopia de absorÃÃo atÃmica e anÃlise termogravimÃtrica foram usadas na caracterizaÃÃo do polÃmero purificado e no estudo do envelhecimento in vitro e in vivo da guta-percha. A degradaÃÃo tÃrmica in vitro do polÃmero guta-percha purificado foi monitorado por espectroscopia de IV. O aumento das bandas devido a grupos hidroxilas (OH; 3430-3440 cm-1) e carbonilas (C=O; 1720-1730 cm-1) foram detectados, provavelmente devido a produtos de degradaÃÃo tais como Ãlcoois, Ãcidos carboxilicos, hidroperÃxidos, aldeidos, cetonas, Ãteres e Ãsteres. Um decrÃscimo na banda de 840 cm-1 devido à quebra =C-H tambÃm foi detectado. O efeito de alguns componentes dos cones (ZnO, BaSO4 e graxas) na oxidaÃÃo tÃrmica in vitro do polÃmero guta-percha foi analisado por espectroscopia IV com a evoluÃÃo das bandas de hidroxila, bandas de carbonila e decrÃscimo da banda de =C-H, assumindo como quebra da ligaÃÃo dupla do isopreno. O tempo de induÃÃo (ti) e as constantes aparentes de velocidade para a degradaÃÃo foram determinados. Os valores de ti para o polÃmero guta-percha foram menores do que o observado para a borracha natural (isÃmero-cis). A adiÃÃo de ZnO ao filme de guta-percha antecipa o inÃcio da degradaÃÃo, enquanto a adiÃÃo de BaSO4 o retarda. A adiÃÃo de cera nÃo mudou o tempo de induÃÃo. O processo de envelhecimento in vivo do cone guta-percha foi monitorado por GPC apÃs a extraÃÃo dos cones durante o retratamento seguido pela separaÃÃo do polÃmero remanescente. A massa molar do poliisopreno decresce com o tempo, mas em uma taxa lenta. No dente com cÃrie e infecÃÃo periapical, a diminuiÃÃo na massa molar foi mais elevada do que no dente de raiz saudÃvel. As anÃlises de IV no envelhecimento in vivo da guta-percha mostrou a produÃÃo de grupos carbonilas e hidroxilas indicando que o processo à oxidativo. As anÃlises 1H-RMN confirmaram a formaÃÃo de hidriperÃxidos durante o envelhecimento in vivo. Observou-se tambÃm que ZnO contidos nos cones diminui com o tempo de envelhecimento, devido ao contato com fluidos tissulares. Experimentos com cones nÃo envelhecidos em contato com saliva artificial e Ãgua tambÃm mostraram a diminuiÃÃo da massa do cone com o tempo devido a liberaÃÃo de ZnO. Oito marcas de cones de guta-percha disponÃveis no Brasil foram tambÃm caracterizadas. A composiÃÃo mÃdia foi similar a outras marcas investigadas. O estudo de calorimetria exploratÃria diferencial (DSC) mostrou que o polÃmero guta-percha possui duas fases cristalinas (a e b). As mudanÃas na fase cristalina ocorrem durante o aquecimento tÃrmico.
description Gutta-percha cones are the most widely used material for root canal filling. They are composed of gutta-percha rubber (trans 1,4-polyisoprene), ZnO, BaSO4 and wax or resins. Gel permeation chromatography (GPC), Infrared spectroscopy (IR), nuclear magnetic resonance (NMR), atomic absorption spectroscopy and thermogravimetric analysis were used in the characterization of purified gutta-percha polymer and in the study of the in vitro and in vivo aging. The in vitro thermal degradation of purified gutta-percha polymer was monitored by IR spectroscopy. The increase of bands due to hydroxyl (OH; 3430-3440 cm-1) and carbonyl groups (C=O; 1720-1730 cm-1) were detected, probably due to products of degradation such as alcohols, carboxylic acid, hydroperoxide, aldehyde, ketone, ether or ester. A decrease on the band at 840 cm-1 due to =C-H was also detected. The effect of some components of cones (ZnO, BaSO4 and wax) in the in vitro thermal oxidation of gutta-percha polymer was carried out by IR spectroscopy through the evolution of hydroxyl band, carbonyl band and the decrease of =C-H band, assumed as related to the cleavage of isoprene double bond. The induction time (ti) and the apparent rate constants during early step of degradation were determined. The ti values for gutta-percha polymer was smaller than the observed for natural rubber (cis-isomer). Addition of ZnO to the gutta-percha anticipated the beginning of film degradation, while the addition of BaSO4 delayed it. Wax addition did not change the nduction time. The in vivo aging process of gutta-percha cones was monitored by GPC after the extraction of remaining cones during the retreatment followed by the polymer isolation. The molar mass of polyisoprene decreased with time, but in a slow rate. In tooth with caries and periodontal fection, the decrease in molar mass was higher than in healthy root canal. IR analysis of the in vivo aged gutta-percha showed the production of carbonyl and hydroxyl groups indicating that the process is oxidative. 1H-NMR analysis confirmed the formation of hydroperoxide during in vivo aging. It was also observed that the ZnO content in the cones decreases with increasing of aging time, due the contact with tissue fluids. Experiment with non aged cones in contact with artificial saliva and water also showed the decrease of cone mass with time due to the release of ZnO. Eight brands of gutta-percha cones available in Brazil were also characterized. The average composition was similar to other brands investigated. Differential scanning calorimetric study showed that gutta-percha polymer possess two crystalline phases (a and b). The changes in crystalline phase occur during thermal heating.
publishDate 2007
dc.date.issued.fl_str_mv 2007-09-04
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/doctoralThesis
status_str publishedVersion
format doctoralThesis
dc.identifier.uri.fl_str_mv http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=1391
url http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=1391
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language por
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dc.publisher.none.fl_str_mv Universidade Federal do CearÃ
dc.publisher.program.fl_str_mv Programa de PÃs-GraduaÃÃo em QuÃmica InorgÃnica
dc.publisher.initials.fl_str_mv UFC
dc.publisher.country.fl_str_mv BR
publisher.none.fl_str_mv Universidade Federal do CearÃ
dc.source.none.fl_str_mv reponame:Biblioteca Digital de Teses e Dissertações da UFC
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