EFFECT OF TOPICAL FLUORIDE APPLICATION BEFORE AND AFTER AMALGAM RESTORATION PLACEMENT ON RECURRENT CARIES INHIBITION

Purpose: To evaluate the in vitro caries inhibition effects of 1.23% A PF foam topical fluoride treatment of cavity preparations, prior to re storation placement and after restoration placement. Materials and Met hods: Sixty standardized Class V preparations were placed in molars. R andomly, 40 teeth received an amalgam restoration. Twenty other teeth had Ice 1.23% APF foam applied to preparation surfaces for 1 minute, t hen an amalgam restoration was placed. The APF was not rinsed away pri or to restoration, it was displaced by the pressure of the amalgam bei ng condensed into the preparation. Twenty of the initial 40 amalgam re storations had 1 cc 1.23% APF foam applied to the external tooth/resto ration margins for 4 minutes, the remaining 20 amalgam restorations ac ted as the controls. Acid-resistant varnish was placed, leaving 1 mm o f tooth adjacent to restoration margins exposed. All specimens were su bjected to an artificial caries challenge (pH 4.4) for 5 days. Section s of 100 mu m were cut longitudinally through the restored margins, ph otographed under polarized light microscopy, then demineralized areas adjacent to restoration margins were quantitated. Results: Results dem onstrated the mean (+/- S.D.) area (mu m(2)) of demineralization 100 l an from the restoration margins to be: amalgam 10,221 +/- 524, amalgam with 1-minute APF over preparation 529 +/- 557, amalgam with 4-minute APF over external surface 736 +/- 359. ANOVA and Duncan's (P< 0.05) i ndicated both 1.23% APF foam topical fluoride treatment regimens exhib ited significantly less demineralization at restoration margins than t he non-treated amalgam control. There was no significant difference be tween the two fluoride placement regimens examined in this study.