Fluoride Recharge of a New Protective Coating

Objectives:  Compare the fluoride recharge of an experimental coating material, EXM-713, to another RMGI material, 3M™ ESPE™ Vitrebond Plus Liner/Base.  EXM-713 is a resin-modified glass ionomer coating material.

Methods:   Cured 20x1mm disks were stored separately in deionized water at 37°C.  Fluoride release was measured after 0.5, 1, 2, 4, 8, 24, 48, and 72hr using fluoride selective electrode and TISAB II.  Dentifrice treatments were applied at 72, 95, and 119hr; fluoride data were collected at  1, 2, 3, 5, 24hr after each treatment; treatment comprised soaking disk 2min in slurry of 3M™ ESPE™ ControlRx™ 5000ppm Fluoride Prescription Dentifrice with deionized water (water:dentifrice=3:1).  Data after treatment were compared to immediately before treatment via one-way paired T-test (p<0.05).

Results:  Cumulative fluoride release rate, microgramF/cm²/hr (n=5).  Within each recharge period and material, groups with superscript * are pre-recharge, H are higher than pre-recharge, E are equivalent to pre-recharge  (p>0.05).

Conclusions:

The fluoride release rate of both EXM-713 and VBP is higher after dentifrice treatment versus before, lasting up to 5 hr for EXM-713, 3hr for VBP.  The recharge levels at 95 hr and 119 hr were not statistically different, but statistically higher than at 72 hr, showing that the effect is repeatable.  EXM-713 and VBP can repeatably recharge and re-release fluoride from application of a prescription-strength dentifrice.