IADR Abstract Archives
Assessment of hydraulic conductance of functionalized calcium carbonate (FCC) occluded dentin tubules
Objectives: A previous morphology study revealed hydroxyapatite coated functionalized calcium carbonate (FCC) particles occlude dentin tubules. Occlusion was more efficient the higher FCC content in test products, the smaller their average diameter and at co-presence of silica. Aggregated particles were detected up to 2µm in tubules depth.
The current study aimed to evaluate the efficacy of FCC occluded dentin tubules with respect to their hydraulic conductance (HC) as function of test products with different FCC contents, particle sizes in absence and presence of silica. Additionally, occlusion stability against acid challenge was investigated.
Methods: Particles with averaged diameters FCC-A: 5.5µm and FCC-B: 2.0µm mixed in silica-free hydroxymethyl (HMC) suspension with 5% FCC-A, 5% and 10% FCC-B were compared to respective contents in silica-based toothpastes (TP), negative and positive controls. Eight treatment groups with eight samples each were generated.
Dentin disks obtained from retained human molars were brushed with respective products for 1min, stored in the slurry for another 1min and rinsed off before their HC was determined according to Pashley. Flow rates of untreated versus treated disks, prior and after acid challenge at pH 2 for 1min were recorded.
Results: All TP show a decrease in HC by 82.0%±7.2% to 90.7%±4.9%, relatively independent of particle size and content, consistent with the positive control. In contrast, occlusion by HCM with 10% FCC-B was 1.5 and 2 times more efficient than for 5% FCC-B and 5% FCC-A, respectively. Acid challenge caused a decrease in occlusion efficacy by 5%-15% for TP and 25%-46% for HMC treated samples.
Conclusions: Results are consistent with the morphology study – FCC occludes dentin tubules. They are relative acid resistant the higher FCC content and the smaller the particles, particularly in presence of silica. Thus, FCC provides a great potential for product developments against dentin hypersensitivity.
The study was supported by Omya International AG.
The current study aimed to evaluate the efficacy of FCC occluded dentin tubules with respect to their hydraulic conductance (HC) as function of test products with different FCC contents, particle sizes in absence and presence of silica. Additionally, occlusion stability against acid challenge was investigated.
Methods: Particles with averaged diameters FCC-A: 5.5µm and FCC-B: 2.0µm mixed in silica-free hydroxymethyl (HMC) suspension with 5% FCC-A, 5% and 10% FCC-B were compared to respective contents in silica-based toothpastes (TP), negative and positive controls. Eight treatment groups with eight samples each were generated.
Dentin disks obtained from retained human molars were brushed with respective products for 1min, stored in the slurry for another 1min and rinsed off before their HC was determined according to Pashley. Flow rates of untreated versus treated disks, prior and after acid challenge at pH 2 for 1min were recorded.
Results: All TP show a decrease in HC by 82.0%±7.2% to 90.7%±4.9%, relatively independent of particle size and content, consistent with the positive control. In contrast, occlusion by HCM with 10% FCC-B was 1.5 and 2 times more efficient than for 5% FCC-B and 5% FCC-A, respectively. Acid challenge caused a decrease in occlusion efficacy by 5%-15% for TP and 25%-46% for HMC treated samples.
Conclusions: Results are consistent with the morphology study – FCC occludes dentin tubules. They are relative acid resistant the higher FCC content and the smaller the particles, particularly in presence of silica. Thus, FCC provides a great potential for product developments against dentin hypersensitivity.
The study was supported by Omya International AG.