Prevention of Erosion and Abrasion by a High Fluoride Concentration Gel Applied at High Frequencies

Abstract

The aim of this study was to determine maximum attainable protection of enamel from erosion and erosion abrasion using a highly fluoridated gel with and without additional fluoride from toothpaste. Thirty-six bovine enamel specimens were subjected to six erosive attacks per day (1% citric acid with pH 2.3 for 30 s), while the rest of the day the specimens were in artificial saliva. There were four treatment groups (9 specimens in each group): fluoride-free toothpaste/saliva slurry twice daily (group T0), fluoride-containing toothpaste/saliva slurry twice daily using 1,250 ppm F toothpaste (group TF), fluoride-containing toothpaste/saliva slurry twice per day plus application of a highly fluoridated gel (12,500 ppm F) twice a day for 120 s (group 2F) and a group with gel application 8 times a day (group 8F). Additionally, half of each specimen in all groups was subjected to brushing abrasion during application of the toothpaste/saliva slurry. Brushing abrasion alone led to no observable enamel loss measured with profilometry. After 14 days of cycling of erosion without toothbrushing abrasion, high-fluoride gel application 2 or 8 times daily showed significantly less enamel loss (median 24/19 µm) than with toothpaste with or without fluoride (41/45 µm). After 14 days of cycling of erosion and toothbrushing abrasion, gel application 2 or 8 times daily (33/29 µm) showed significantly less enamel loss than toothpaste with or without fluoride (57/62 µm). We conclude that a highly fluoridated acidic gel is able to protect enamel from erosion and toothbrushing abrasion while fluoridated tooth paste provides little protection.