Fluoride release and anti-erosive effects of dentifrices containing PVM/MA copolymers

To evaluate fluoride release from dentine discs and study the effects of dentine tubule occlusion and erosion prevention of dentifrices containing fluoride and PVM/MA copolymers in a cycling erosive challenge model.

Human dentine discs, 15 in each group, were eroded by 1.0% citric acid and treated by ProNamel(®) (PRN, 1450ppm fluoride), Colgate(®) Total Sensitive (CTS, 1100ppm fluoride), a prototype dentifrice containing 5000ppm fluoride and 2% PVM/MA copolymers (PVD) and distilled water (control). Fluoride release from each dentine disc was evaluated every 2h in a 12-h period. For cycling erosive challenges, dentine discs were treated by dentifrice slurries twice daily, followed by immersion in saliva and erosive challenges by orange juice. Dentine discs were stored in saliva between treatment cycles and the cycling erosive challenges were repeated for 15 days. On days 5, 10, and 15, size of dentine tubule openings and level of dentine tubule occlusion were evaluated with a 3D scanning microscope.

PVD released more fluorides than other dentifrices in a 12-h period (p<0.05). CTS released more fluorides than PRN at 2, 4, 6, and 8h following a single application (p<0.05). The size of the dentine tubules was smaller and the number of occluded dentine tubules was greater in the CTS and PVD groups than those in the control and PRN groups on day 15 of the erosive challenges.

Bioadhesive PVM/MA copolymers facilitate fluoride retention and release from dentine discs, and promote dentine tubule occlusion and erosion prevention when combined with hydrated silica particles.