Potassium sodium tartrate, which whitens teeth from an electrical charge generated by brushing, may be an enamel-safe alternative to peroxide-based whitening agents, according to a study recently published in BDJ Open.
Additionally, a potassium sodium tartrate formula containing fluoride appeared to demonstrate a similar level of shade improvement compared to peroxide-fluoride treatments, the authors wrote.
“In vitro results indicate potassium sodium tartrate could provide an effective and enamel-safe alternative to peroxide-based whitening,” wrote the authors, led by Angelina Ivanova of the Queen Mary University of London (BDJ Open, February 3, 2026, Vol. 12:1, 14).
The study evaluated the tooth-whitening effectiveness of potassium sodium tartrate compared with peroxide-based treatments, as well as its effects on enamel preservation and performance in a novel toothpaste formulation. Two in vitro studies examined the whitening efficacy and enamel protection relative to carbamide peroxide, Ivanova and co-author Valeriia Buzova, MSc, wrote.
In the first experiment, stained bovine enamel blocks were treated with prototype toothpastes containing 2% potassium sodium tartrate, 2% carbamide peroxide, a base-only control, or deionized water using simulated brushing and a cumulative 3.5-hour immersion. Outcomes included stain removal index (SRI%) and surface microhardness recovery (%SMHR). In the second experiment, stained human enamel samples were treated with commercial-style toothpastes containing 2% potassium sodium tartrate over simulated one-week and one-month periods.
In the first experiment, potassium sodium tartrate and carbamide peroxide produced statistically equivalent stain removal (SRI%: 30.06 ± 7.08 vs. 30.02 ± 6.58). Visual and colorimetric analyses showed that toothpaste formulations containing 2% potassium sodium tartrate or 2% carbamide peroxide were the most effective at removing pigmented enamel stains, they wrote.
However, carbamide peroxide significantly reduced enamel microhardness (%SMHR: -15.8 ± 4.38), while potassium sodium tartrate preserved microhardness (0.08 ± 4.06). Enamel treated with potassium sodium tartrate or no whitening agent showed no surface integrity changes. In the second experiment, after one month, the potassium sodium tartrate formulation with fluoride achieved shade improvement comparable to the peroxide-fluoride control (4.76 ± 1.51 vs. 4.38 ± 0.58 shades).
Nevertheless, the study had limitations. The whitening effect of potassium sodium tartrate depends on brushing-induced mechanical activation of its piezoelectric properties, preventing its use in gels, strips, or rinses, the authors added.
“Based on the present in vitro evidence, potassium sodium tartrate emerges as a highly promising candidate for safer tooth whitening,” they concluded.
