• Pornsri Patimanukaseam
• Yuttana Punya-ngarm
• Chanunya Gesprasert
• Patou Suraprasert

Objective  The purpose of this study was to compare fluoride dissociation after addition to plain milk, high calcium milk, and high acidity fermented milk.

Material and method  UHT milk available in Bangkok were randomly collected. They were 10 brands of plain milk, 5 high calcium milk and 11 fermented milk. pH and fluoride concentrations at baseline were measured by pH electrode and fluoride electrode, respectively. After addition of 0.5 mg fluoride to 100 ml milk, the fluoride concentrations were measured and the percentage of free fluoride ion release was calculated. The differences in fluoride content and percentage of fluoride release were analyzed by ANOVA at 95% confidence interval.

Result  pH of plain milk, high calcium milk and fermented milk were 6.470 + 0.086, 6.616 + 0.125, and 3.869 + 0.121, and the mean fluoride concentrations at baseline were 0.108 + 0.034, 0.157 + 0.149, and 0.314 + 0.140 ppm, respectively. After the addition of 0.5 mg fluoride, the percentage of free fluoride ion release from plain milk, high calcium milk had significantly less percentage of free fluoride ion than plain milk (p<0.05), while fermented milk showed no significant difference.

Conclusion  High calcium milk decreased the dissociation of fluoride added while the increase of milk acidity did not significantly affect fluoride dissociation.

(CU Dent J 2002;25:211-6)