Delivery of Low-Diluted Toothpaste during Brushing Improves Enamel Acid Resistance

Area of Science:

• Dental science
• Materials science

Background:

• Toothpaste viscosity decreases with saliva dilution during brushing.
• This may lead to premature washout and reduced fluoride uptake in caries-prone areas.
• The impact of toothpaste physical properties on enamel acid resistance is not well understood.

Purpose of the Study:

• To investigate the effect of toothpaste dilution on bovine enamel's acid resistance.
• To determine the critical dilution threshold impacting enamel protection.

Main Methods:

• Bovine enamel samples were subjected to five toothpaste dilution levels (0%, 100%, 67%, 50%, 25%).
• Acid resistance was assessed using pH cycling following toothpaste application.
• Enamel defects and Vickers hardness were measured.

Main Results:

• Enamel defects significantly increased at 50% (2.00x) dilution and higher compared to 67% (1.50x).
• Vickers hardness decreased, and mineral loss increased with greater toothpaste dilution.
• A significant difference in mineral loss was noted between 67% (1.50x) and 50% (2.00x) dilutions (p < 0.01).

Conclusions:

• Toothpaste dilution beyond 67% (1.5x) diminishes enamel acid resistance.
• Maintaining lower toothpaste dilution in high-risk areas can enhance the efficacy of active ingredients for caries prevention.