IADR Abstract Archives
2- Photon analysis of nanogel-infiltrated adhesive-dentine interfaces
Objectives: A new class of dental adhesive based on reactive nanogel additives controls the hydrophobic character of the adhesive resin whilst reducing shrinkage stress and improving mechanical properties1. Nanogels are globular methacrylate-based cross-linked particles 10-90 nm in diameter, and can be swollen by and dispersed in resin monomers.
Nanogels migratory/ swelling behaviours within such a system are unclear. 2-photon scanning laser microscopy allows high-resolution images of the fluorescently tagged nanogel adhesive interface, providing detailed morphological information and details of nanogels’ migration. Such an understanding may lead to further optimisation of these materials.
Methods: Model BisGMA/HEMA 60:40 w/w solvated adhesives were prepared. Nanogels were a 70:30 molar ratio of isobornyl methacrylate (IBMA) and urethane dimethacrylate (UDMA), labelled with a Rhodemine Red fluorescent probe. Labelled nanogels were added to the resin at 20 wt%. Six human third molars each had mesial and distal class V cavity preparations and were restored at 1h, 3h, 24h, 48h, 7d and 14d after creation of the nanogel adhesive. Adhesive interfaces were imaged using a tunable two-photon laser using appropriate excitation- emission profiles for dentinal collagen and labelled nanogels.
Results: The 2-Photon images show nanogel distribution and microstructural interface features across all hybrid interfaces studied. Nanogels were shown to homogeneously disperse within the resin matrix and infiltrate finer tubular structures (<1um).
Conclusions: The 2 photon imaging modality provides detailing of interface structure, using both intrinsic fluorescence of tooth tissue and with the selection of suitable fluorescent probes. This technique could assist in further studies surrounding adhesive placement protocol and interaction between adhesives and tooth tissue.
1) Improved Dental Adhesive Formulations Based on Reactive Nanogel Additives., Moraes, R.R.; Garcia, J.W.; Wilson, N.D.; Lewis, S.H.; Barros, M.D. et al. (2012) Journal of Dental Research vol. 91 (2) p. 179-184
Nanogels migratory/ swelling behaviours within such a system are unclear. 2-photon scanning laser microscopy allows high-resolution images of the fluorescently tagged nanogel adhesive interface, providing detailed morphological information and details of nanogels’ migration. Such an understanding may lead to further optimisation of these materials.
Methods: Model BisGMA/HEMA 60:40 w/w solvated adhesives were prepared. Nanogels were a 70:30 molar ratio of isobornyl methacrylate (IBMA) and urethane dimethacrylate (UDMA), labelled with a Rhodemine Red fluorescent probe. Labelled nanogels were added to the resin at 20 wt%. Six human third molars each had mesial and distal class V cavity preparations and were restored at 1h, 3h, 24h, 48h, 7d and 14d after creation of the nanogel adhesive. Adhesive interfaces were imaged using a tunable two-photon laser using appropriate excitation- emission profiles for dentinal collagen and labelled nanogels.
Results: The 2-Photon images show nanogel distribution and microstructural interface features across all hybrid interfaces studied. Nanogels were shown to homogeneously disperse within the resin matrix and infiltrate finer tubular structures (<1um).
Conclusions: The 2 photon imaging modality provides detailing of interface structure, using both intrinsic fluorescence of tooth tissue and with the selection of suitable fluorescent probes. This technique could assist in further studies surrounding adhesive placement protocol and interaction between adhesives and tooth tissue.
1) Improved Dental Adhesive Formulations Based on Reactive Nanogel Additives., Moraes, R.R.; Garcia, J.W.; Wilson, N.D.; Lewis, S.H.; Barros, M.D. et al. (2012) Journal of Dental Research vol. 91 (2) p. 179-184
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