Essay about The Theory Of Dentin Adhesion

1842 Words Apr 27th, 2016 8 Pages
INTRODUCTION :
The concept of dentin adhesion presently used involves the nanomechanical retention which is due to polymerisation of hydrophilic monomers around acid exposed collagen fibres.1 The entanglement of these monomers within the exposed collagen fibres gives rise to the so called Hybrid layer , which is also referred as Resin infiltrated Dentin layer.2 The presence of hybrid layer is important for attainment of a leakage free interface between the cavity walls and resin composite.2
After acid etching, the demineralized collagen matrix is present in a denatured state, beneath which lies the residual hydroxyapatite crystals.3 Monomer infiltration throughout the thickness of demineralised dentin is important for successful adhesion. However the low surface free energy of demineralised collagen could possibly reduce diffusion of hydrophilic monomer through the existing nanospaces. Also the presence of water around the collagen fibres can cause difficulty in proper bonding leading to the phenomenon of nanoleakage.2 The phenomenon nanoleakage was first advocated by Sano et al in 1994, and they described it as a microscopic leakage occurring inside the structure of resin infiltrated dentin layer or the Hybrid layer.4
Therefore the removal of demineralised collagen matrix with deproteinizing agents has been suggested. Various studies have proposed the use of sodium hypochlorite , a non specific deproteinizing agent in various concentrations for complete removal of…

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