Revista de Odontologia da UNESP
https://revodontolunesp.com.br/article/doi/10.1590/1807-2577.1076
Revista de Odontologia da UNESP
Original Article

Morphological and chemical changes of dentin after applying different sterilization methods

Avaliação das alterações morfológicas e químicas da dentina após a aplicação de diferentes métodos de esterilização

Carvalho, Cláudio Antonio Talge; Xavier, Ana Claudia Carvalho; Valera, Marcia Carneiro; Jorge, Antonio Olavo Cardoso; Ferraz, Marcia Maciel Menezes; Oliveira, Luciane Dias de

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Abstract

Aim: The present study evaluated the morphological and chemical changes of dentin produced by different sterilization methods, using scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometry (EDS) analysis. Material and method: Five human teeth were sectioned into 4 samples, each divided into 3 specimens. The specimens were separated into sterilization groups, as follows: wet heat under pressure; cobalt 60 gamma radiation; and control (without sterilization). After sterilization, the 60 specimens were analyzed by SEM under 3 magnifications: 1500X, 5000X, and 10000X. The images were analyzed by 3 calibrated examiners, who assigned scores according to the changes observed in the dentinal tubules: 0 = no morphological change; 1, 2 and 3 = slight, medium and complete obliteration of the dentinal tubules. The chemical composition of dentin was assessed by EDS, with 15 kV incidence and 1 μm penetration. Result: The data obtained were submitted to the statistical tests of Kruskall-Wallis and ANOVA. It was observed that both sterilization methods – with autoclave and with cobalt 60 gamma radiation – produced no significant changes to the morphology of the dentinal tubules or to the chemical composition of dentin. Conclusion: Both methods may thus be used to sterilize teeth for research conducted in vitro.

Keywords

Radiation, microscopy, electron, chemical analysis, dentin.

Resumo

Objetivo: O presente estudo teve como objetivo avaliar as alterações morfológicas e químicas na dentina geradas por diferentes métodos de esterilização, através de microscopia eletrônica de varredura (MEV) e da análise por espectrometria de energia dispersiva de raios-X. Material e método: Seccionaram-se 5 dentes humanos em 4 amostras, as quais foram divididas em 3 espécimes cada, totalizando 60 espécimes. Os espécimes foram separados conforme os grupos de esterilização: calor úmido sob pressão; radiação gama cobalto 60; controle (sem esterilização). Após a esterilização, os 60 espécimes foram analisados por MEV, usando 3 aumentos: 1500X, 5000X, 10000X. As imagens foram analisadas por 3 examinadores previamente calibrados, que distribuíram escores referentes às alterações observadas nos túbulos dentinários: 0 = sem alteração morfológica, 1 = baixa obliteração dos túbulos dentinários, 2 = moderada obliteração, 3 = completa obliteração. A composição química da dentina foi avaliada por meio do processo EDS, com 15 kV de incidência e penetração de 1 μm. Os dados obtidos foram submetidos ao teste estatístico de Kruskall-Wallis com nível de significância de 5%. Resultado: De acordo com os resultados obtidos, verificou-se que a esterilização tanto por autoclave quanto por radiação gama cobalto 60 não provocou alterações significativas na morfologia dos túbulos dentinários e na constituição química da dentina. Conclusão: Concluiu-se que ambos os métodos podem ser utilizados para a esterilização de dentes em pesquisa in vitro.

Palavras-chave

Radiação, microscopia, análise química, dentina.

References

 


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