An intraoral study of caries induced on enamel in contact with fluoride-releasing restorative materials

The aim was to study the effect of three fluoride-releasing restorative mat erials on sound enamel of approximal teeth under cariogenic conditions intr aorally. Bovine enamel slabs were paired with four hemispherical samples fr om each of three test materials (Ketac Molar, ESPE; Vitremer, F-2000, both from 3M) and one control material (Pertac II, ESPE), Their curved surface t ouched enamel at a contact point allowing space for plaque accumulation. Pa irs were inserted in the buccal flanges of 2 lower dentures for 70 days. In itially and upon dismantling, enamel surf ace microhardness was measured an d the increase in length of indentation in micrometers was recorded at a di stance of 0, 0.4, 0.8 and 1.2 mm from the contact point, Respective values were: Pertac II: 16.0 +/-7.5, 27.6 +/- 15.4, 38.6 +/- 23.3, 47.8 +/- 25.2; F-2000: 11.89 +/-9.6, 15.8 +/- 14.2, 21.0 +/- 15.0, 25.1 +/- 15.2; Ketac Mo lar: 6.6 +/-6.8, 9.4 +/-7.0, 9.5 +/-8.0), 13.4 +/-9.4; Vitremer: 2.7 +/-4.1 , 3.5 +/-3.5, 3.6 +/-4.5), 7.4 +/-5.2. Caries protection was Vitremer 82% > Ketac Molar 69% > F-2000 42% in relation to Pertac II (p <0.001), Sections of the slabs examined with polarized light showed typical subsurface lesio ns only in the Pertac II group, areas of pseudoisotropy in the F-2000 and K etac Molar groups and no signs of lesion in the Vitremer group. Copyright ( C) 2001 S. Karger AG, Basel.