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. …show more content…
10% Ascorbic acid was applied for a period of 20s followed by rinsing with water for 20s.
Group 4 : : Teeth were etched with 37% phosphoric acid for 15s, rinsed with water for 20s and blot dried. 5% Zinc hydroxide was applied for a period of 20s followed by rinsing with water for 20s.
All the teeth were dried and dentin bonding agent was applied onto the cavity with a applicator tip. The bonding agent was applied gently into the cavity for 10 s. the bonding agent was left for a period of 10 s and the excess was removed using a air stream, followed by light curing for 20 s. The restorative procedure was performed by inserting composite in three horizontal increments. Each increment was individually light cured for 20 s from all the surfaces to ensure complete polymerization. Before placing the final increment a transparent matrix band was used to contour the restoration. The restoration surfaces were polished using a sand paper disc. The root apices were sealed using composite and the entire teeth except the bonded interface and 1mm on the teeth surfaces next to the interface were coated with two layers of nail …show more content…
The collagen has a low surface energy compared with hydroxyapatite with high surface energy. After acid etching the surface energy is decreased by the exposure of collagen fibres.17 To increase the bonding between composite resin and dentin the weak zone in the hybrid layer, the exposed collagen fibres should be completely removed. The dentin obtained after removal of the collagen fibres in known as deproteinized
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. …show more content…
10% Ascorbic acid was applied for a period of 20s followed by rinsing with water for 20s.
Group 4 : : Teeth were etched with 37% phosphoric acid for 15s, rinsed with water for 20s and blot dried. 5% Zinc hydroxide was applied for a period of 20s followed by rinsing with water for 20s.
All the teeth were dried and dentin bonding agent was applied onto the cavity with a applicator tip. The bonding agent was applied gently into the cavity for 10 s. the bonding agent was left for a period of 10 s and the excess was removed using a air stream, followed by light curing for 20 s. The restorative procedure was performed by inserting composite in three horizontal increments. Each increment was individually light cured for 20 s from all the surfaces to ensure complete polymerization. Before placing the final increment a transparent matrix band was used to contour the restoration. The restoration surfaces were polished using a sand paper disc. The root apices were sealed using composite and the entire teeth except the bonded interface and 1mm on the teeth surfaces next to the interface were coated with two layers of nail …show more content…
The collagen has a low surface energy compared with hydroxyapatite with high surface energy. After acid etching the surface energy is decreased by the exposure of collagen fibres.17 To increase the bonding between composite resin and dentin the weak zone in the hybrid layer, the exposed collagen fibres should be completely removed. The dentin obtained after removal of the collagen fibres in known as deproteinized