Composition and crystallographic changes on enamel when irradiated by Nd:YAG or Er,Cr:YSGG lasers and its resistance to demineralization when associated with fluoride
Carregando...
Data
Data de publicação
2010
Orientador
Título da Revista
ISSN da Revista
Título do Volume
É parte de
É parte de
É parte de
É parte de
INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING - LASERS IN DENTISTRY XVI
Exportar
Resumo
This study investigated the compositional and crystallographic changes on enamel when irradiated by
Er,Cr:YSGG (λ=2.78µm, 8.5J/cm2
) or Nd:YAG (λ=1064nm, 84.9J/cm2
associated with black coating), its
resistance to demineralization when irradiation is associated with fluoride (APF-gel), and CaF2-like material
formation and retention. Sample surfaces were analyzed by ATR-FTIR (4000–650cm-1, 4cm-1) resolution.
Irradiation with Er,Cr:YSGG laser promoted a significant decrease on carbonate content of enamel. After
Nd:YAG irradiation, it was observed a significant decrease of carbonate and amides I and II. X-ray diffraction
showed that both laser irradiations promoted formation of α-tricalcium phosphate and tetracalcium phosphate,
and a significant increase on the crystal growth of the enamel apatite (ANOVA, p<0.05 was used for all
analysis). These changes can explain the improved resistance of enamel to demineralization observed in the
second part of the study, in which 240 enamel slices were divided in 8 groups, received 4 min of professional
fluoride gel (APF-gel 1.23%F-
) applied before or after irradiation. After treatments, the formation of calcium
fluoride (CaF2) was determined. The remaining slabs of each group were submitted to a 10-day pH-cycling
model and, subsequently, enamel demineralization was evaluated by cross-sectional microhardness. Both lasers
significantly reduced enamel demineralization (ANOVA, p<0.05), and the previous APF-gel application
followed by laser showed the higher reduction of enamel demineralization. CaF2 formed before pH-cycling was
significantly higher in groups were APF was associated with laser irradiation. After demineralization, these
groups also presented higher CaF2 retention in respect to isolated treatments (only APF or only laser),
suggesting its anticaries potential.
Como referenciar
ZEZELL, D.M.; ANA, P.A.; BENETTI, C.; GOULART, V.P.; BACHMANN, L.; TABCHOURY, C.P.M.; CURY, J.A. Composition and crystallographic changes on enamel when irradiated by Nd:YAG or Er,Cr:YSGG lasers and its resistance to demineralization when associated with fluoride. In: INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING - LASERS IN DENTISTRY XVI, January 24, 2010, Sao Francisco, California. Proceedings... DOI: 10.1117/12.842967. Disponível em: http://repositorio.ipen.br/handle/123456789/17947. Acesso em: 30 Dec 2025.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.