Conclusion and Outlook

Main Research Findings

This study systematically analyzed the application of diatomaceous earth (DE) in toothpaste deodorization and led to the following main conclusions:

Deodorization Mechanism:
Diatomaceous earth primarily removes oral odors through a physical adsorption mechanism. Its porous structure provides a large specific surface area, allowing it to effectively capture various odor molecules. In addition, DE may also participate in deodorization through chemical adsorption and catalytic effects, enhancing its overall efficiency.

Deodorization Effect:
DE demonstrates a remarkable deodorizing effect against various types of oral odors, including food residue odors, morning halitosis, and smoke-induced bad breath. In particular, it exhibits strong adsorption capacity for key odor-causing compounds such as indole and dimethyl sulfide.

Comparison with Other Ingredients:
Compared with baking soda and activated carbon, DE shows a more balanced performance in terms of adsorption efficiency, safety, and overall functionality. Notably, DE offers better adsorption for large-molecule odor substances, is gentler on tooth enamel, and is safer for long-term use.

Impact on Product Performance:
Appropriate addition of DE has a positive influence on toothpaste rheology and sensory properties. DE improves flow and extrusion stability while providing a moderate abrasive effect and pleasant texture. Moreover, it enhances cleaning, whitening, and antibacterial performance, contributing to a more comprehensive oral care experience.

Safety:
Food-grade diatomaceous earth has been certified as GRAS (Generally Recognized as Safe) by the FDA, confirming its high safety and suitability for long-term use. Compared with other deodorizing agents, DE shows minimal irritation to the oral mucosa and gentle action on enamel, making it particularly suitable for individuals with sensitive teeth.

Application Recommendations

Based on the above findings, the following recommendations are proposed for applying diatomaceous earth in toothpaste formulations:

• Dosage Control:
  The DE content should be maintained between 10–28%, with the optimal range being 15–20% to achieve the best balance between deodorization efficiency and overall product performance.

• Particle Size Selection:
  Choose DE particles in the 10–28 μm range, ideally around 15 μm, to ensure optimal balance between cleaning efficiency and comfort.

• Formulation Synergy:
  DE can be combined with other deodorizing ingredients such as baking soda, activated carbon, or sodium phytate to achieve synergistic effects. For instance, the DE–phytate combination significantly improves the removal of tea, coffee, and tobacco stains.

• Product Type Adaptation:
  DE is particularly suitable for premium functional toothpaste, such as whitening, refreshing, or sensitivity-relief types. For cost-sensitive formulations, DE can be blended with more economical deodorizing agents.

• Usage Guidance:
  It is recommended to use DE-based toothpaste twice daily for at least 2 minutes each time to maximize adsorption and cleaning efficiency. Light rinsing is sufficient after brushing to retain a small amount of DE in the mouth and prolong the freshness effect.

Future Research Directions

Despite its promising potential, further research on diatomaceous earth in toothpaste applications is still warranted in the following areas:

• Modification Studies:
  Physical or chemical modification of DE could further enhance its adsorption capacity and selectivity, improving performance toward specific odor compounds.

• Synergistic Mechanisms:
  Investigating the interaction mechanisms between DE and other toothpaste components (e.g., fluorides, antibacterial agents) may support the development of high-efficiency composite formulations.

• Long-Term Efficacy Evaluation:
  Conducting long-term clinical trials is essential to assess the sustained effects and safety profile of DE-based toothpastes.

• Nanotechnology Applications:
  Exploring nano-structured diatomaceous earth could potentially increase adsorption performance and bioavailability.

• Sustainability Considerations:
  Research into eco-friendly mining and processing technologies for DE will help minimize environmental impact and align with green manufacturing principles.

Summary

As a natural, safe, and effective deodorizing ingredient, diatomaceous earth holds great promise in the oral care industry. With continued research and technological advancement, its application in toothpaste formulations will further expand—offering consumers superior, healthier, and more sustainable oral care solutions.