Fluoride ion release from ultraviolet light-cured sealants containing sodium fluoride.

The ability of uv light-cured fissure sealants to release fluoride ion from different concentrations of sodium fluoride (NaF), over a 3-week period was studied. Two hundred samples of sealant were prepared in which 1 group contained no fluoride (control) and 4 others contained NaF at 0.05, 0.2, 0.5, and 2% concentrations, respectively. The fluoride ion released by each sample after 1 day, 3 days, 1 week, and 3 weeks was determined by a specific fluoride ion electrode. The study demonstrated that the quantity of fluoride ions released increases, in general, with time and concentration. The vulnerability of occlusal pits and fissures to dental decay1-3 is a problem which has prompted the development of pit and fissure sealants. 4-7 Since topical applications of sodium fluoride (NaF) solutions and gels have been shown to be effective in reducing dental caries, 8-11 the introduction of NaF to a fissure sealant could enhance the reduction of pit and fissure decay. The concept of increasing the caries-reducing ability of pit and fissure sealants was investigated in studies which initially added fluoride to varnish. 12-14 Swartz et al. ~s conducted an in vivo study to test the feasibility of imparting an anti-cariogenic property to pit and fissure sealants by adding 2-5% NaF. These data indicated that fluoride added to a sealant resin material in the amount reported substantially increased the fluoride content of the enamel, reduced its solubility in acid, and provided an acceptable anticariogenic mechanism. Since it has been found that the pretreatment of enamel with fluoride and the addition of fluoride to acid-etching solutions reduces bond strength, 16-2o the addition of fluoride to fissure sealants would appear to be worthy of study in the search for a better cariesreducing procedure. The objectives of this study were to measure the ability of fissure sealant a to release fluoride ion from different concentrations of sodium fluoride b added to the sealant throughout a 3-week period as well as to determine the amount of fluoride ion released relative to the concentration of NaF at each designated time of analysis. Methods and Materials The fissure sealant was combined with 4 different concentrations of NaF (0.05, 0.2, 0.5, 2.0%) by means of a mechanical mixerc to determine the ability of the sealant to release fluoride ion. These NaF concentrations were selected because of their use and effectiveness in mouth rinses (0.05, 0.2, 0.5%), 1° in dentifrices (0.2%) 9 and in topical application (2.0%). 8 Samples of the same sealant material without the addition of NaF served as controls. Standard sizes of the sealant samples were produced by using plastic moldsa containing 10 compartments supplied for use with the sealant. New molds were used for the preparation of each group of sealant/NaF combination. In order to find the best method of curing the sealant and sealant/fluoride mixture, 2 different uv light sources e,f were tried. No difference was found between 2 uv light sources. Because of the large sample size used in this study (N = 200) one uv light source a Nuva Seal -LD Caulk Co: Milford, DE. b Sodium Fluoride (powder, Respond A209) -Ward’s Natural Science Establishment, Inc: Rochester, NY. c Vortex-Genie -Scientific Industries: Springfield, DE. d Delton Sealant -Johnson & Johnson: East Windsor, NJ. e Nuva Lite -LD Caulk Co: Milford, DE. ~Black Ray-Longwave Ultraviolet (Model X4) -Ultraviolet Products, Inc: San Gabriel, Ca. PEDIATRIC DENTISTRY: December 1985/Vol. 7 No. 4 287 was used to cure the sealant and sealant/fluoride mixture s. f