Efeito da terapia fotodinâmica sobre a resistência de união e a penetrabilidade dentinária de diferentes protocolos de cimentação de pinos de fibra de vidro
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Data
2017-03-16
Autores
Ramos, Anna Thereza Peroba Rezende [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Essa pesquisa avaliou o efeito da Terapia Fotodinâmica (PDT) sobre diferentes protocolos de cimentação de pinos de fibra de vidro com cimentos resinosos convencionais ou autoadesivos, assim como os cimentos ionoméricos, através da resistência de união e penetrabilidade dentinária por meio de ensaio mecânico “push-out”, análise do padrão de fratura e microscopia confocal à laser. Foram utilizados dentes humanos, com raízes padronizadas em 15mm e tratados endodonticamente com o sistema ProTaper (Dentsply, Ballaigues, SW), irrigados com hipoclorito de sódio a 2,5% e obturados pela técnica do cone único com cimento endodôntico contendo resina epóxi (AH Plus; Dentsply DeTrey GmbH, Konstanz, Germany). Após armazenamento em estufa com umidade a 37ºC por 7 dias, foi preparado o espaço e instalado o pino de fibra de vidro com o sistema White Post DC 2 (FGM, Joinville, SC, BR). De forma aleatória, as raízes foram divididas em 6 grupos (n=10) de acordo com o sistema de cimentação e a utilização da PDT. Os grupos que fazem parte da utilização da PDT tiveram seu canal radicular irrigado com soro fisiológico, seco, preenchido com fotossensibilizador (azul de metileno), permaneceu em repouso por 5 minutos e irradiado por uma fibra ótica adaptada em fonte de emissão, então foi removido o corante e seguido o protocolo de cimentação do pino conforme o fabricante recomenda tanto para o tratamento do pino, quanto para o tratamento da dentina radicular e manipulação do cimento. Nessa etapa foi adicionado rodamina B à cimentação para permitir avaliação em microscopia confocal à laser. Após inserção das raízes verticalmente em matrizes plásticas e completa polimerização dos cimentos, o conjunto foi seccionado em 3 fatias de acordo com os terços radiculares. Os pinos de fibra de vidro foram submetidos ao teste de push-out, determinado o padrão de fratura e avaliação da penetrabilidade dentinária do cimento. A análise estatística foi feita através do teste ANOVA e pós-teste Tukey, com nível de significância de 5%. A utilização da PDT exerce efeito negativo sobre a resistência de união do sistema de cimentação RelyX ARC na dentina cervical, e sobre a penetração dentinária do sistema RelyX ARC, no terço apical e cervical radicular. A PDT exerce efeito negativo sobre a resistência de união quando utilizado CIV no terço cervical, contudo não influenciou sobre a penetração dentinária.
The aim of this study was to evaluate the effects of photodynamic therapy (PDT) on the glass-fiber post cementation protocols using conventional or self-adhesive resin cements and a glass ionomer cement (GIC) on the bond strength and dentinal penetrability. The specimens were submitted to the push-out test, failure mode and laser confocal microscopy evaluation. Human canine roots standardized in 15mm were endodontically-treated using ProTaper (Dentsply, Ballaigues, SW) system, irrigated with 2.5% sodium hypochlorite and obturated with single cone technique and epoxi-based sealer (AH Plus; Dentsply DeTrey GmbH, Konstanz, Germany). The specimens were stored under 100% relative humidity, at 37oC for 7 days. Afterwards, the intracanal prosthetic space was prepared and the glass-fiber post (White Post DC 2, FGM, Joinville, SC, BR) was placed. The roots were randomly divided into 6 groups (n = 10) according to the cementation system and PDT use. The groups that used PDT were irrigated with saline, dried, filled with photosensitizer (methylene blue), left untouched for 5min and irradiated using a laser emission source. The pigment was removed, the post cementation protocol was handled according to the manufacturer´s recommendations. Rhodamine B was added in the cementation system to facilitate the evaluation of confocal laser microscopy. The roots were vertically placed inside plastic matrices and filled with polyester resin. After 24h, the set was sectioned in 3 slices according to the root thirds. The glass-fiber posts were subjected to the push-out test, the failure mode and dentinal penetrability analysis. The data were submitted to ANOVA and Tukey post-tests, at 5% significance level. PDT presented a negative effect on the bond strength of RelyX ARC cementation system to the cervical dentin and on the dentinal penetrability of RelyX ARC system in the apical and cervical thirds. Moreover, PDT showed a negative effect on the bond strength of GIC to the cervical third; however, it did not influence the dentinal penetrability.
The aim of this study was to evaluate the effects of photodynamic therapy (PDT) on the glass-fiber post cementation protocols using conventional or self-adhesive resin cements and a glass ionomer cement (GIC) on the bond strength and dentinal penetrability. The specimens were submitted to the push-out test, failure mode and laser confocal microscopy evaluation. Human canine roots standardized in 15mm were endodontically-treated using ProTaper (Dentsply, Ballaigues, SW) system, irrigated with 2.5% sodium hypochlorite and obturated with single cone technique and epoxi-based sealer (AH Plus; Dentsply DeTrey GmbH, Konstanz, Germany). The specimens were stored under 100% relative humidity, at 37oC for 7 days. Afterwards, the intracanal prosthetic space was prepared and the glass-fiber post (White Post DC 2, FGM, Joinville, SC, BR) was placed. The roots were randomly divided into 6 groups (n = 10) according to the cementation system and PDT use. The groups that used PDT were irrigated with saline, dried, filled with photosensitizer (methylene blue), left untouched for 5min and irradiated using a laser emission source. The pigment was removed, the post cementation protocol was handled according to the manufacturer´s recommendations. Rhodamine B was added in the cementation system to facilitate the evaluation of confocal laser microscopy. The roots were vertically placed inside plastic matrices and filled with polyester resin. After 24h, the set was sectioned in 3 slices according to the root thirds. The glass-fiber posts were subjected to the push-out test, the failure mode and dentinal penetrability analysis. The data were submitted to ANOVA and Tukey post-tests, at 5% significance level. PDT presented a negative effect on the bond strength of RelyX ARC cementation system to the cervical dentin and on the dentinal penetrability of RelyX ARC system in the apical and cervical thirds. Moreover, PDT showed a negative effect on the bond strength of GIC to the cervical third; however, it did not influence the dentinal penetrability.
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Palavras-chave
Fotoquimioterapia, Cimentos de resina, Espécies de oxigênio reativas, Pinos dentários