d. Topical Solutions.
(1) Sodium fluoride. As a topical solution, sodium fluoride has been shown
to reduce the incidence of caries by at least 20 percent in nonfluoridated communities.
Its effectiveness in fluoridated communities has not been established. A 2 percent
solution is recommended to be applied in a series of four treatments given several days
apart and following a single prophylaxis at age 3 to afford protection to the deciduous
teeth and as groups of permanent teeth erupt at ages 7, 11, and 13. Adjustment to that
schedule should be made according to each child's pattern of tooth eruption. Following
a thorough prophlylaxis, the teeth are isolated with cotton rolls, dried thoroughly, and
wet completely with a two percent aqueous sodium fluoride solution. The solution is left in
place for 3 to 5 minutes, taking precautions to prevent saliva contamination. A
prophylaxis prior to the remaining topical treatments is usually not necessary if they are
done within a few days.
(2) Acidulated phosphate fluoride. The topical application of sodium fluoride
solutions and gels acidified with orthophosphoric acid has been demonstrated by clinical
studies to have significant caries-inhibiting effect in children. The preparation most
often employed contains a fluoride concentration of 1.23 percent in approximately 1
percent orthophosphoric acid. Annual topical applications of acidulated phosphate-
fluoride gels in trays have produced reductions in dental caries of 37 to 41 percent.
Daily tray applications of a 0.5 percent gel each school day produced a reduction of
approximately 80 percent in a nonfluoridated area. Both neutral and acidulated
phosphate fluoride gels have been used successfully to control the rampant decay seen
in cases of xerostomia (dry mouth) produced by cancer radiation therapy. In the tray
procedure, a ribbon of gel is placed in the tray, the teeth are dried, the tray is seated
over the teeth and squeezed slightly to expel the gel, and then allowed to remain in
place for four minutes. The patient is instructed not to eat or rinse his mouth for the
next 30 minutes.
When using prophylaxis paste, the PDS must cover porcelain-veneered
crowns with petroleum jelly.
(3) Stannous fluoride. A single application of a freshly prepared 8 percent
aqueous solution of stannous fluoride at 6- to 12-month intervals is the generally
preferred method of use. This method with stannous fluoride requires less time than
the series of four applications of sodium fluoride and appears to produce similar
caries-reducing results. The stannous fluoride solution is applied in basically the same
manner as the other fluoride solutions. Staining has been noted in some clinical studies
using stannous fluoride. Some studies indicate the dark stain to be related to debris
and plaque material rather than tooth structure. Further studies are needed to
completely evaluate this problem.