In vitro cytotoxicity (irritant potency) of toothpaste ingredients.

Area of Science:

• Oral toxicology
• Dermatology
• Material science

Background:

• Toothpaste ingredients vary widely, with some possessing known sensitizing properties.
• Assessing the cytotoxic potential of common toothpaste components is crucial for oral health.
• Understanding ingredient irritancy informs product safety and formulation.

Purpose of the Study:

• To evaluate the cytotoxicity and irritant potency of selected toothpaste ingredients.
• To determine the concentration thresholds (EC50, EC10) for cell death induced by these ingredients.
• To assess the impact of these ingredients on oral mucosal tissue histology.

Main Methods:

• Reconstructed human gingiva (RHG) models were exposed to various concentrations of Xylitol, Propylene glycol (PEG), Sodium metaphosphate (SMP), Lemon, Peppermint, Fluoride, Cinnamon, Sodium dodecyl sulphate (SDS), and Triclosan.
• The MTT assay was employed to determine the EC50 (concentration causing 50% cell death) and EC10 (concentration causing 10% cell death).
• Hematoxylin & eosin staining and microscopy were used to analyze histological tissue damage.

Main Results:

• Xylitol, PEG, and SMP showed no significant cytotoxicity or histological damage.
• Lemon, Peppermint, Cinnamon, and SDS exceeded EC50 concentrations, causing significant tissue damage and indicating potential harm to oral mucosa.
• Triclosan and Fluoride exceeded EC10 but not EC50, with no clear detrimental histological effects observed.

Conclusions:

• Specific toothpaste ingredients (Lemon, Peppermint, Cinnamon, SDS) demonstrate significant cytotoxicity.
• Triclosan and Fluoride were found to be less cytotoxic within the tested concentrations.
• The study highlights the need for manufacturers to adhere to higher quality and safety standards in toothpaste formulation.