IADR Abstract Archives
Dentin Tubules Occlusion: In-vitro Hydraulic Conductance and Surface Morphology Study
Objectives: Although several test models are available, there is still a need to refine testing methodologies to assess the dentin tubules-occluding efficacy of oral care products. Aim of this project was to develop and establish a testing-protocol which includes measuring fluid flow through dentin tubules and microscopic analyses by confocal Laser-Scanning-Microscopy (CLSM) of dentin surface before and after treatment with toothpaste slurries.
Methods: The basic in-vitro experimental hydraulic conductance design to study fluid flow through dentin tubules was introduced by Pashley. Based on this, a modified experimental set-up was developed allowing for intermittent removal of dentin samples for imaging on exactly identical regions of the samples before and after treatments and/or hydraulic conductance measurements.
Two toothpastes with different tubules-occluding properties were investigated to validate the experimental set-up and evaluate correlation of flow-reduction with visually identifiable dentin tubules occlusion. Per toothpaste, 12 hydraulic conductance experiments (using 12 different coronal dentin disks) were performed. Images were captured by CLSM at baseline and after toothpaste slurry treatment.
Results: Toothpaste 1 showed high flow-reduction of 77±10%, toothpaste 2 revealed light occluding effect with flow-reduction of 19±15%. It was managed to perform CLSM measurements and to quantify the number of open tubules as well as their mean diameter and area before and after treatment. These parameters are useful for assessing the closing of tubules. The high occluding potential of toothpaste 1 was confirmed by the reduction of the number of open tubules and tubules diameters, respectively; no significant changes of the tubules parameters were detected for toothpaste 2 with low flow-reduction.
Conclusions: The modified in-vitro experimental set-up allows investigation of tubules occluding efficacy of toothpastes by hydraulic conductance and visually by CLSM using the same dentin disks. Results of both complementary methods can be correlated and validate each other.
The study was sponsored by Colgate-Palmolive Europe sàrl.
Methods: The basic in-vitro experimental hydraulic conductance design to study fluid flow through dentin tubules was introduced by Pashley. Based on this, a modified experimental set-up was developed allowing for intermittent removal of dentin samples for imaging on exactly identical regions of the samples before and after treatments and/or hydraulic conductance measurements.
Two toothpastes with different tubules-occluding properties were investigated to validate the experimental set-up and evaluate correlation of flow-reduction with visually identifiable dentin tubules occlusion. Per toothpaste, 12 hydraulic conductance experiments (using 12 different coronal dentin disks) were performed. Images were captured by CLSM at baseline and after toothpaste slurry treatment.
Results: Toothpaste 1 showed high flow-reduction of 77±10%, toothpaste 2 revealed light occluding effect with flow-reduction of 19±15%. It was managed to perform CLSM measurements and to quantify the number of open tubules as well as their mean diameter and area before and after treatment. These parameters are useful for assessing the closing of tubules. The high occluding potential of toothpaste 1 was confirmed by the reduction of the number of open tubules and tubules diameters, respectively; no significant changes of the tubules parameters were detected for toothpaste 2 with low flow-reduction.
Conclusions: The modified in-vitro experimental set-up allows investigation of tubules occluding efficacy of toothpastes by hydraulic conductance and visually by CLSM using the same dentin disks. Results of both complementary methods can be correlated and validate each other.
The study was sponsored by Colgate-Palmolive Europe sàrl.