Randomised clinical efficacy trial of potassium oxalate mouthrinse in relieving dentinal sensitivity

ObjectiveThe study aimed to determine the efficacy in relieving dentinal sensitivity of 4 weeks' treatment with an alcohol-free mouthrinse comprising 1.4% potassium oxalate (KO) (Listerine® Advanced Defence Sensitive; LADS), compared with negative and positive controls.MethodsSubjects were randomised to one of three treatments: LADS mouthrinse – twice-daily toothbrushing with Crest® Cavity Protection Regular toothpaste, rinsing with water and then 10 mL LADS mouthrinse, followed by expectoration; negative control (twice-daily brushing with Crest Cavity Protection Regular toothpaste); or positive control (twice-daily brushing with Sensodyne® Original desensitising toothpaste). Dentine sensitivity was assessed at baseline and after 2 and 4 weeks by Yeaple probe (tactile pressure; patient-reported discomfort by visual analogue scale [VAS]), air blast (VAS) and global subjective sensitivity (VAS). Oral tolerance was monitored throughout the study.ResultsAt 2 weeks, subjects treated with the positive control and LADS mouthrinse showed significant reductions (p<0.05) in sensitivity scores versus the negative control. At 4 weeks, sensitivity decreased by 110% in the positive-control subjects versus negative-control subjects (p<0.001); sensitivity decreased by 80% in subjects receiving LADS mouthrinse versus negative-control subjects (p<0.05). No serious treatment-related oral adverse events were reported.ConclusionsThe positive control (Sensodyne Original) significantly reduced sensitivity compared with the negative control (Crest toothpaste alone), thus validating the study. The LADS mouthrinse (1.4% KO mouthrinse) significantly reduced sensitivity compared with the negative control, suggesting that LADS mouthrinse was responsible for the clinical effect observed. The treatments were well tolerated.Clinical significanceTo our knowledge, this is the first randomised clinical study to demonstrate the efficacy of a KO-containing mouthrinse (LADS) in relieving dentinal sensitivity.