Summary
This parallel-group, randomised, double-blind, negative-control trial (n=127 randomised; 120 completed; ISRCTN80733222) evaluated two desensitising toothpaste formulations — 5% potassium nitrate alone (Test Group 1) and 5% potassium nitrate combined with 2.18% aluminum lactate (Test Group 2) — against a placebo (washout toothpaste without potassium nitrate or aluminum lactate) over 8 weeks in Chinese adults aged 18-65 with dentin hypersensitivity. Both test toothpastes significantly reduced dentin hypersensitivity (Dentin Sensitivity Index, DSI) compared to placebo for both tactile and air stimulus from 2 weeks onward. Test Group 2 showed greater efficacy than Test Group 1 at 4 weeks (air stimulus) and 8 weeks (both stimuli). This clinical trial does not measure heavy-metal contamination in toothpastes. Aluminum lactate is an intentional active ingredient at 2.18%, not a contaminant; its inclusion here is to flag that aluminum is present as an intentional formulation component in desensitising toothpastes, which is relevant context for interpreting aluminum occurrence data in finished toothpaste products.
Evidence Fitness
Context only for toothpaste metals contamination. The aluminum signal in this paper refers to 2.18% aluminum lactate as an intentional active pharmaceutical ingredient for dentinal tubule occlusion, not to aluminum as a trace contaminant. The clinical efficacy data are not metals-evidence. This source does not contribute to the metals evidence tables on Toothpaste (Cat 2).
Methods (brief)
Parallel-group, randomised, double-blind, negative-control trial. 127 adult volunteers (mean age approximately 49 years; 55% female) with dentin hypersensitivity in at least one premolar or molar enrolled at the Affiliated Stomatological Hospital of Chongqing Medical University (ethics approval P2024-144-001). Randomisation to three groups: placebo (n=42), Test Group 1 (5% KNO3, n=43), Test Group 2 (5% KNO3 + 2.18% aluminum lactate, n=42). Toothbrushes (Systema Regular Toothbrush, Lion Corporation) provided. Brushing protocol: 2 min twice daily for 8 weeks; toothpaste amount based on the patient’s hand to simulate realistic use. DSI assessed at baseline, immediately after brushing, 2 weeks, 4 weeks, 4 weeks plus 24 hours, and 8 weeks using tactile (Yeaple probe) and air stimulus (Schiff index) measures. Statistical analysis: one-way ANOVA with Tukey-Kramer post-hoc; repeated measures ANOVA for time comparisons.
Implications
- Certification: Contextual note that aluminum lactate is an intentional active ingredient in desensitising toothpastes at 2.18% concentration — well above any trace-contamination level. When interpreting aluminum measurements in finished toothpastes from occurrence studies, the formulation type (desensitising vs. standard) may explain part of the observed inter-product variation in aluminum concentrations.
- Courses: Useful background on desensitising toothpaste mechanisms (nerve depolarisation via potassium nitrate; tubule occlusion via aluminum lactate/strontium phosphate deposits).
- App: Not applicable.
Related evidence
None — this source does not carry metals contamination data applicable to the toothpaste wiki page.
Update history
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