Effects of pre- or post-application of calcium chloride on occluding ability of potassium oxalate for the treatment of dentin hypersensitivity

Purpose: To evaluate whether calcium ion supply using 1-6 mol/L CaCl ₂ solution could enhance the occluding ability of dentin tubules with 30% potassium oxalate treatment. Methods: Calcium chloride solution (1-6 mol/L) was applied to dentin disks before or after application of 30% potassium oxalate solution. Occluding ability after potassium oxalate treatment was evaluated with scanning electron microscopic (SEM) observation and measurement of dentin permeability. In addition, the composition of the precipitate formed when mixing potassium oxalate and calcium chloride was analyzed with a powder x-ray diffractometer (XRD). Results: SEM observations revealed that the dentin tubules were occluded homogeneously and completely with the precipitate when calcium chloride solution was applied before or after potassium oxalate treatment. However, the depth of the precipitate in dentin tubules from the dentin surface became shallower when pre-treated with calcium chloride before potassium oxalate. Although dentin permeability was greatly reduced in both groups, no significant difference could be observed between samples with and without calcium chloride application.