Purpose: To evaluate the effect on dentin of chondroitin sulfate and L-arginine on dentin tubule occlusion.
Methods: The dentin samples were activated by submersion in an aqueous ( aq. ) solution of chondroitin sulfate ( ChS) or L-arginine prior to application of a commercial or custom-made toothpaste. After rinsing with water and ultrasonication, adhesion to dentin and occlusion of dentin tubules were evaluated by scanning electron microscopy and the elemental composition of the deposits was evaluated by energy-dispersive x-ray spectroscopy.
Results: Rinsing a dentin sample with a solution of ChS resulted in an increase in the adherence of dentifrices containing either titanium dioxide (TiO₂ ) or calcium-based nanoparticles [ hydroxyapatite ( HA\ or calcium carbonate( to the dentin surface. ChS does not appear to enhance the adherence of dentifrices lacking TiO₂. Pretreatment by L-arginine improved adherence of calcium carbonate nanoparticles, but less efficiently than ChS. Addition of nanoparticles of hydroxyapatite or calcium citrate to dentifrices improved their adherence to dentin without any pre-treatment.
Clinical significance: The significant increase in adherence to the dentin surface of dentifrices of either TiO₂ or calcium-supplying nanoparticles to the dentin surface following pre-treatment with ChS or L-arginine opens the door to the development of two-step dental treatments, which accomplish dentin tubule occlusion and help to deliver active dentifrice components to the dentin surface. The ability of the aqueous pastes of nanoparticles of hydroxyapatite or calcium citrate to occlude dentin tubules enables the formulation of desensitizing dentifrices, which also supply the mineral and organic nutrients to the tooth surface.
Copyright©American Journal of Dentistry.