Our study shows that a 1-min treatment with either
a 1.23% APF gel or foam does not result in significant
visual changes or weight losses in the surface of a composite
resin with barium boroaluminosilicate glass and
silica filler particles. However, visual scores and weight
loss both are significantly higher in composite resins
treated with either the 1.23% gel or foam for 4 rain.
Weight losses also were reported2 in a strontium-glassfilled
composite resin treated 4-min with 1.23% APF
gel, as compared with the group treated with water,
although the differences were not evaluated statistically.
The series of 4-min immersions was selected so
that the total time would be similar to a standard 4-min
treatment. A series of 1-min immersions was more appropriate
than one 4-rain immersion to simulate a clinical
situation where these APF agents are used as originally
formulated and marketed. In addition, the 4-min
immersions allowed a longitudinal series of weight
changes on the same set of specimens.