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One of the most common questions patients with dentinal hypersensitivity ask is, “Will this toothpaste work immediately?” A recently published randomized controlled trial in BDJ Open [Jun 2026] provides new evidence to help answer that question
The study enrolled 127 adults, with 120 completing the 8-week trial. Participants were randomly assigned to use either a toothpaste containing 5% potassium nitrate, a toothpaste containing 5% potassium nitrate and 2.18% aluminum lactate, or a placebo. Dentin hypersensitivity was assessed at baseline, 60 seconds after the first supervised brushing, and after 2, 4, and 8 weeks using two validated methods: tactile stimulation (using a Yeaple electronic pressure probe) and air-blast stimulation (using the Schiff Cold Air
Sensitivity Scale).
Yes—but with an important qualification.
Immediately after a single supervised brushing, participants using the 5% potassium nitrate toothpaste showed a statistically significant reduction in tactile dentinal hypersensitivity compared with baseline, meaning greater
pressure could be applied before discomfort was experienced. Although airblast sensitivity also improved from baseline, the reduction was not significantly greater than placebo at this early time point. The authors therefore concluded that the immediate desensitizing effect was observed only for tactile stimulation.
It is also important to note that this study evaluated tactile and air-blast sensitivity. The immediate effect of potassium nitrate on other triggers, such as cold beverages, sweet foods, or acidic stimuli, was not investigated in this trial.
The benefits became more consistent over time. From 2 weeks onward, both potassium nitrate-containing toothpastes produced significantly greater reductions in dentinal hypersensitivity than placebo for both tactile and airblast stimulation. Improvement continued through the 4- and 8-week evaluations, reinforcing the importance of regular twice-daily use.
Interestingly, the toothpaste containing 5% potassium nitrate combined with 2.18% aluminum lactate demonstrated greater reductions in hypersensitivity than potassium nitrate alone at several later time points. The authors suggest this may reflect the complementary mechanisms of the two ingredients: potassium nitrate primarily reduces nerve excitability, while aluminum
lactate promotes dentinal tubule occlusion, providing both rapid neural desensitization and sustained relief.
This randomized controlled trial suggests that a 5% potassium nitrate toothpaste can provide immediate relief from tactile dentinal hypersensitivity after a single supervised brushing. However, more consistent and clinically meaningful reductions in both tactile and air-blast sensitivity were observed after two weeks of regular use.
Based on this study, clinicians can advise patients that while some improvement may be noticed after the first use, continued twice-daily brushing is important to achieve maximum benefit. As with any single clinical trial, these findings should be interpreted alongside the broader body of evidence supporting potassium nitrate-containing desensitizing toothpastes.
Ishii K, Suzuki T, Akabane C, Iizumi G, Suzuki N, Fukuda Y, Suzuki K, Kawaguchi N, Zhu R, Li D, Zhou Z, Hu D. Toothpastes containing potassium nitrate alone versus potassium nitrate combined with aluminum lactate in reducing dentin hypersensitivity: a randomized controlled trial. BDJ Open. 2026 Jun 23;12(1):64. doi: 10.1038/s41405-026-00452-x. PMID: 42336824.
