Side Effects of Sodium Lauryl Sulfate Applied in Toothpastes: A Scoping Review

Published In: American Journal of Dentistry
Publication Year: 2022

Study Design

This publication is a scoping review, conducted to systematically map the literature on the side effects of sodium lauryl sulfate (SLS) in toothpaste formulations. It follows the PRISMA extension protocol for scoping reviews.

Funding Sources

No specific funding sources were disclosed. The authors declared no conflicts of interest.

PICO Framework – what was studied and how?

Population:

General toothpaste users, including subgroups such as individuals with recurrent aphthous stomatitis, atopic conditions, and varying skin types.

Intervention:

Use of toothpaste containing sodium lauryl sulfate (SLS).

Comparison:

Use of SLS-free toothpaste, or those containing alternative surfactants (e.g., cocamidopropyl betaine [CAPB]).

Outcomes:

• Incidence of mucosal irritation or ulceration

• Frequency, duration, and pain intensity of aphthous ulcers

• Toxic reactions and epithelial damage

• Skin and mucosal sensitivity

In Paragraph Form:
This scoping review evaluated the potential side effects of sodium lauryl sulfate (SLS) in toothpaste across various populations. By comparing SLS-containing products with SLS-free alternatives, the review examined outcomes such as oral and dermal irritation, ulceration rates, and potential toxicity. The review also explored how different concentrations of SLS affected epithelial integrity and healing, particularly in individuals prone to aphthous ulcers.

Inclusion and Exclusion Criteria

Inclusion Criteria:

• Human studies

• Articles in English

• Studies reporting health or side effects of SLS

• Study types: retrospective, prospective, observational, cross-sectional, cohort studies, and case reports

Exclusion Criteria:

• Animal studies

• Irrelevant articles

• Lack of scientific data or information on SLS

Demographics and Study Scope

• This was a literature review, so no singular participant pool exists.

• Included multiple studies (more than 20) spanning clinical trials, observational research, and case reports.

• Notably included patients with recurrent aphthous stomatitis, varied skin types, and different age groups (e.g., pre- and post-menopausal women).

Primary Outcome Variables and Results

Primary Outcomes:

• Mucosal Desquamation: Increased significantly with higher concentrations of SLS (P<0.04 to P<0.001).

• Aphthous Ulcers: SLS toothpaste users experienced significantly more frequent and painful ulcers than those using SLS-free or CAPB-based alternatives.

• Epithelial Damage: High concentrations (>0.5%) caused apoptosis and necrosis in epithelial cells (P=0.003).

• Retention of SLS in Oral Cavity: 38% immediately after brushing; 2% after 2 hours.

Conclusions

Sodium lauryl sulfate in toothpaste is associated with:

• Increased risk of mucosal irritation, ulceration, and inflammatory reactions

• Potentially longer healing times for aphthous ulcers

• Oral mucosal barrier damage via mucin disruption and epithelial apoptosis

SLS-free formulations may reduce these risks, particularly for sensitive individuals, without compromising plaque or gingivitis control.

Discussion: Strengths and Limitations

Strengths:

• Comprehensive scope including over 20 relevant studies.

• Followed structured PRISMA guidelines.

• Provided detailed comparisons between SLS and non-SLS formulations.

Limitations:

• Limited number of randomized controlled trials.

• Results drawn from varied study designs, some with inconsistent methodologies.

• More long-term, controlled studies are needed to solidify findings.

Citation

Kasi SR, Özcan M, Feilzer AJ. Side effects of sodium lauryl sulfate applied in toothpastes: A scoping review. Am J Dent. 2022;35(2):84-88.
Available at: Journal Link

Visual Aids

Simple Chart: SLS Impact on Oral Mucosa