PURPOSE: To evaluate the laboratory dentin occlusion efficacy and effects on dentin permeability of a new multi-benefit dentifrice in order to gain insight into the mechanism of action of a novel technology for dentin hypersensitivity relief based on a specially-designed silica and copolymer system. METHODS: RESULTS: Dentin specimens treated with Test Dentifrices 1 and 2 were significantly occluded compared to Placebo Dentifrice and Negative Control Dentifrice when visualized with CLSM. The level of occlusion remaining after challenge with cola was highest for dentin treated with Test Dentifrice 1 in CLSM xz views. Test Dentifrice 1 produced dentin surface deposits and tubule plugs containing silicon in addition to calcium and phosphorus as indicated by ESCA and EDX. CLSM visualization of fluorescently-tagged material confirmed occlusion by the specially-designed silica which was localized at the dentin tubule openings. Imaging of dentin by CLSM after the 4-day cycling model revealed a significantly higher amount of occluded tubules for dentin treated with Test Dentifrice 1 compared to the Negative Control Dentifrice or Test Dentifrice 2. Etched dentin treated with the Test Dentifrice 1 was significantly less permeable compared to that treated with the Negative Control Dentifrice, exhibiting over 80% reduction in dentin permeability. The occlusion provided by the Test Dentifrice 1 was maintained and provided significantly better reduction in permeability after extended pulpal pressure and acid challenge compared to dentin treated with Test Dentifrice 2.
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