Fluoride release from a New Protective Coating

Objectives:  Compare the fluoride release of an experimental coating material to a similar RMGI material and to two sealants.  EXP is a resin-modified glass ionomer coating material in a paste/paste delivery, based on the chemistry of 3M™ ESPE™ Vitrebond™ Plus Liner/Base (VBP).  The sealants were GC Fuji™ Triage (FT) and Pulpdent™ Embrace™ Wetbond™.

Methods:    Disk-shaped, 1-mm thick by 20-mm diameter samples were cured by exposing them to illumination from a dental curing light for 120 seconds on each side of the disk.  Each was immersed separately in 25 ml of deionized water in a specimen vial, and stored in a 37°C oven. At each measurement interval, the specimen vial was removed from the oven, the leachate solution removed and reserved, and replaced with 25 ml of fresh deionized water. Fluoride concentration was measured with a fluoride ion specific electrode, after addition of  TISAB II buffer.  Data were analyzed via one-way ANOVA and compared with Tukey's T-test (p<0.05).

Results:  Cumulative fluoride release (stdev) in µg F/cm² is shown below.

Material	1d	7d	2wk	4wk
EXP	58.1(3.6)a	134.4(7.7)c	184.8(10.2)e	244.4(12.4)g
FT	45.7(11.9)a	74.2(19.4)d	89.6(22.5)f	106.4(26.6)h
VBP	57.5(6.4)a	130.4(14.8)c	177.5(19.7)e	234.6(24.2)g
EW	38.9(0.6)b	75.3(1.5)d	87.9(3.0)f	100.2(4.0)h

Groups identified by the same superscript letter are not significantly different (p>0.05).

EXP was equivalent to VBP at all times; EXP and VBP were higher than FT and EW at 7d, 2wk, and 4wk.  FT is equivalent to EW at all times. At 1d, EXP and VBP were higher than EW and equivalent to FT.

Conclusions:

EXP displays sustained fluoride release, comparable to other glass ionomers.