IADR Abstract Archives
The Role of Dentin Matrix Proteins in Attracting Staining Molecules
Objectives: Better understanding of how biological properties of dentin structure influences inherent tooth colour will lead to better treatments for tooth staining.This study will Investigate the role of dentin matrix proteins in attracting staining molecules in real time.
Methods: Human teeth were collected from the School of Dentistry Toothbank and enamel, pulp and caries removed. 15 teeth were sectioned into 100um slices and treated with either Sodium hypochlorite (deproteinizing, 5.6%) for 12 days or EDTA (demineralizing, 0.5M, PH 8) for 3 days prior to staining with Orange II Sodium salts. Digital images were captured at 1, 6, 12, 24, 48, 72, and 168 hours during staining. 15 further teeth were powdered using a percussion mill cooled with liquid nitrogen. Proteins were extracted from powdered dentin using 10% EDTA (pH 7.2) and exhaustively dialyzed prior to lyophilization. Real-time biomolecular interactions were performed using a BIAcore T100 system. Antibodies for decorin and Dentin phosphprotein (DPP) were rehydrated to concentrations of 50ug/mL in sodium acetate, immobilised onto a series S CM5 sensorchip and dentin matrix extract incorporated onto the coated chip. Orange II (0-1mg/ml in HBS-EP buffer) was injected into the system and kinetic analyses performed to determine dissociation constants for the interaction of decorin and DPP within the dentin matrix with the staining molecule.
Results: After 1hr in Orange II, staining was observed in demineralized teeth whilst no staining was observed on deproteinized samples. After 168hrs, staining of demineralized teeth had a much higher intensity measured by ImageJ software compared with deproteinized teeth. Mean equilibrium dissociation constants (KD) were 561.6uM and 783.5uM for decorin and DPP respectively.
Conclusions: Demineralised dentin can retain stain compared with deproteinized dentin. Real time kinetic analyses suggest decorin and DPP interact strongly with staining molecules influencing stain localization within tooth structure.
Methods: Human teeth were collected from the School of Dentistry Toothbank and enamel, pulp and caries removed. 15 teeth were sectioned into 100um slices and treated with either Sodium hypochlorite (deproteinizing, 5.6%) for 12 days or EDTA (demineralizing, 0.5M, PH 8) for 3 days prior to staining with Orange II Sodium salts. Digital images were captured at 1, 6, 12, 24, 48, 72, and 168 hours during staining. 15 further teeth were powdered using a percussion mill cooled with liquid nitrogen. Proteins were extracted from powdered dentin using 10% EDTA (pH 7.2) and exhaustively dialyzed prior to lyophilization. Real-time biomolecular interactions were performed using a BIAcore T100 system. Antibodies for decorin and Dentin phosphprotein (DPP) were rehydrated to concentrations of 50ug/mL in sodium acetate, immobilised onto a series S CM5 sensorchip and dentin matrix extract incorporated onto the coated chip. Orange II (0-1mg/ml in HBS-EP buffer) was injected into the system and kinetic analyses performed to determine dissociation constants for the interaction of decorin and DPP within the dentin matrix with the staining molecule.
Results: After 1hr in Orange II, staining was observed in demineralized teeth whilst no staining was observed on deproteinized samples. After 168hrs, staining of demineralized teeth had a much higher intensity measured by ImageJ software compared with deproteinized teeth. Mean equilibrium dissociation constants (KD) were 561.6uM and 783.5uM for decorin and DPP respectively.
Conclusions: Demineralised dentin can retain stain compared with deproteinized dentin. Real time kinetic analyses suggest decorin and DPP interact strongly with staining molecules influencing stain localization within tooth structure.
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