A novel potassium oxalate-containing tooth-desensitising mouthrinse: A comparative in vitro study

Abstract

ObjectiveTo compare the efficacy of a new potassium oxalate (KO)-containing mouthrinse [Listerine® Advanced Defence Sensitive (LADS)] in reducing dentine permeability and occluding open dentinal tubules versus other desensitising products. MethodsThe permeability of acid-etched dentine disks was measured by hydraulic conductance; dentine surfaces were examined by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The KO concentration was optimised for tubule occlusion by screening formulations containing 0.0–2.0% KO (n=5 disks per concentration). The optimal formulation was compared with five commercial products with non-oxalate occlusion technologies. After establishing the baseline permeability of acid-etched dentine disks, disks (n=6 per product) were randomly treated with the desensitising products (12 treatments, each 60 s, alternated with distilled-water rinses) and permeability was measured at intervals. Occluded disks were acid challenged. All experiments were conducted at room temperature. An unpooled, two-tailed t test was performed to assess between-treatment differences in relative residual permeability. ResultsThe optimal concentration of KO in LADS was 1.4%, which provided ∼100% reduction in dentine permeability after nine treatments. Only LADS reduced permeability to zero and was significantly more effective in reducing dentine permeability than the other products (p≥0.033 vs all other test products). All products partially occluded dentine. The occlusion associated with LADS was substantially more stable in resisting acid challenge versus Colgate® Sensitive Pro-Relief mouthrinse (p=0.054) and significantly more stable versus all other test products (p≥0.045), as determined by dentine permeability. ConclusionLADS was significantly more effective in occluding open dentinal tubules versus other desensitising products. Clinical significanceLADS provides fast, complete and stable intratubular occlusion of patent dentinal tubules.