Enamel de remineralization on teeth adjacent to fluoride releasing materials without dentifrice exposure

Interproximal caries presents a continual clinical concern. The purpose of this study was to evaluate the ability of fluoride-releasing materials to r emineralize incipient caries lesions on adjacent teeth, at the interproxima l site with and without exposure to a fluoridated dentifrice. Thirty extrac ted teeth had Class II preparations placed, then equal numbers were restore d with amalgam (Tytin (3-Kerr), glass ionomer (Ketac Fil(R)-ESPE) or compos ite (Heliomolar(R)-Ivoclar). Thirty additional teeth had 1 x 5 mm artificia l caries lesions formed at the interproximal contact point. One hundred mu thick sections were obtained at the caries sites and polarized photomicrogr aphs were taken. The sections had varnish placed, leaving only the external section site exposed, and were situated back into the original tooth. Thes e teeth were then mounted with the artificial lesion having an interproxima l contact with the adjacent tooth restoration. Specimens were placed in clo sed environments of artificial saliva for two weeks; the saliva was changed every forty-eight hours. AU teeth were cycled through an artificial caries system for thirty minutes, three times per day. Half the specimens in each group were brushed with Crest(R) (Procter and Gamble) for two minutes, twi ce per day. The same sections were again photographed under polarized light and areas of the lesions were digitized quantitatively. Results demonstrat ed the mean (+/- S.D.) percent change in lesion size (water imbibition) for each material nonexposed and exposed to fluoridated dentifrice to be:Amalg am -64.1 +/- 22.0, -1.0 +/- 8.5; Glass Ionomer 2.2 +/- 10.6, 14.0 +/- 7.2; Composite-28.1 +/- 11.7, 18.2 +/- 6.7. Negative numbers represent demineral ization and positive numbers represent remineralization. Duncan's analysis indicated the nonbrushed fluoride-releasing glass ionomer and composite res in to have significantly greater demineralization inhibition compared to th e nonbrushed amalgam group and remineralization enhancement effects on adja cent interproximal lesions (p < 0.05) compared to the brushed amalgam group .