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Exogenous mineralization of hard tissues using photo-absorptive minerals and femto-second lasers; the case of dental enamel.
Anastasiou, A D; Strafford, S; Thomson, C L; Gardy, J; Edwards, T J; Malinowski, M; Hussain, S A; Metzger, N K; Hassanpour, A; Brown, C T A; Brown, A P; Duggal, M S; Jha, A.
Afiliación
  • Anastasiou AD; School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, UK. Electronic address: a.anastasiou@leeds.ac.uk.
  • Strafford S; Leeds Dental School, Worsley Building, University of Leeds, Leeds LS2 9JT, UK.
  • Thomson CL; SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK.
  • Gardy J; School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, UK.
  • Edwards TJ; SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK.
  • Malinowski M; Leeds Dental School, Worsley Building, University of Leeds, Leeds LS2 9JT, UK.
  • Hussain SA; SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK; Cambridge Graphene Centre, Engineering Department, University of Cambridge, 9, JJ Thomson Avenue, Cambridge CB3 0FA, UK.
  • Metzger NK; SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK.
  • Hassanpour A; School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, UK.
  • Brown CTA; SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK.
  • Brown AP; School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, UK.
  • Duggal MS; Leeds Dental School, Worsley Building, University of Leeds, Leeds LS2 9JT, UK; School of Dentistry, The National University of Singapore, Singapore.
  • Jha A; School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, UK.
Acta Biomater ; 71: 86-95, 2018 04 15.
Article en En | MEDLINE | ID: mdl-29462711
A radical new methodology for the exogenous mineralization of hard tissues is demonstrated in the context of laser-biomaterials interaction. The proposed approach is based on the use of femtosecond pulsed lasers (fs) and Fe3+-doped calcium phosphate minerals (specifically in this work fluorapatite powder containing Fe2O3 nanoparticles (NP)). A layer of the synthetic powder is applied to the surface of eroded bovine enamel and is irradiated with a fs laser (1040 nm wavelength, 1 GHz repetition rate, 150 fs pulse duration and 0.4 W average power). The Fe2O3 NPs absorb the light and may act as thermal antennae, dissipating energy to the vicinal mineral phase. Such a photothermal process triggers the sintering and densification of the surrounding calcium phosphate crystals thereby forming a new, dense layer of typically ∼20 µm in thickness, which is bonded to the underlying surface of the natural enamel. The dispersed iron oxide NPs, ensure the localization of temperature excursion, minimizing collateral thermal damage to the surrounding natural tissue during laser irradiation. Simulated brushing trials (pH cycle and mechanical force) on the synthetic layer show that the sintered material is more acid resistant than the natural mineral of enamel. Furthermore, nano-indentation confirms that the hardness and Young's modulus of the new layers are significantly more closely matched to enamel than current restorative materials used in clinical dentistry. Although the results presented herein are exemplified in the context of bovine enamel restoration, the methodology may be more widely applicable to human enamel and other hard-tissue regenerative engineering. STATEMENT OF SIGNIFICANCE: In this work we provide a new methodology for the mineralisation of dental hard tissues using femtosecond lasers and iron doped biomaterials. In particular, we demonstrate selective laser sintering of an iron doped fluorapatite on the surface of eroded enamel under low average power and mid-IR wavelength and the formation of a new layer to substitute the removed material. The new layer is evaluated through simulated brushing trials and nano-indentation. From the results we can conclude that is more acid resistant than natural enamel while, its mechanical properties are superior to that of current restorative materials. To the best of our knowledge this is the first time that someone demonstrated, laser sintering and bonding of calcium phosphate biomaterials on hard tissues. Although we here we discuss the case of dental enamel, similar approach can be adopted for other hard tissues, leading to new strategies for the fixation of bone/tooth defects.
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Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Esmalte Dental / Nanopartículas de Magnetita / Rayos Láser Límite: Animals Idioma: En Revista: Acta Biomater Año: 2018 Tipo del documento: Article Pais de publicación: Reino Unido

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Esmalte Dental / Nanopartículas de Magnetita / Rayos Láser Límite: Animals Idioma: En Revista: Acta Biomater Año: 2018 Tipo del documento: Article Pais de publicación: Reino Unido