The Effect of Copper on Demineralization of Dental Enamel

Abstract

Previous studies have concluded that copper might inhibit enamel demineralization in vitro. Our aim was to assess the effect of copper (Cu2+), with and without amine fluoride, on human dental enamel under cariogenic challenge in situ. In a double-blind randomized four-leg crossover trial, 14 individuals wore a removable appliance containing 2 enamel slabs, 1 containing an artificial caries lesion. During each leg, the appliance was exposed twice daily to one of the test solutions: 1.25 mM CuSO4, amine fluoride (250 ppm F), copper and amine fluoride combined, or a placebo (water). A cariogenic challenge was provided in all cases by 5 daily exposures to 10% sucrose. Slabs were assessed before and after 21 days' exposure by Knoop microhardness and transverse microradiography. Significantly less demineralization was observed with Cu2+ and fluoride in combination than with fluoride treatment alone (p < 0.05), whereas copper alone had no significant protective effect.

Effect of indentation load and time on knoop and vickers microhardness tests for enamel and dentin

“…Numerous previous microhardness studies reported results of both KHN and VHN at different indentation loads and times [4][5][6][7][8][13][14][15] . There are many reasons to perform tests at different conditions.…”

“…There is no agreement on the specifications of the conditions for the test method of a tooth. An examination of the literature reveals that previous studies have used different indenters and various loads and times to investigate the hardness of enamel and dentin [4][5][6][7][8] . From the HK and HV equations, the microhardness value should be constant when loads are varied, because the indentation size increases with an increase in the load.…”

Fluoride dose-response of human and bovine enamel artificial caries lesions under pH-cycling conditions

“…V-SMH and K-SMH were recorded and changes vs. lesion baseline calculated for both Knoop and Vickers indenter types as follows: ΔSMH = SMH post -SMH base . The authors refrained from calculating changes in indentation lengths as this is uncommon for Vickers and for the sake of clarity, although some previous studies [4,13,21,22] highlighted linear correlations between Knoop indentation lengths vs.…”

“…Among those techniques are the 'gold standard' transverse microradiography (TMR), Knoop and Vickers microhardness either used perpendicular (K-SMH, V-SMH) or parallel to the hard tissue surface, polarized light and confocal laser scanning microscopy (both used parallel to the surface), and quantitative light-induced fluorescence (used perpendicular to the surface). Researchers have either shown good [4,21,22] or poor correlations [23,24] between TMR and SMH, depending on the extent of demineralization and lesion mineral distribution. However, previous 5 laboratories approximately monthly; however, determinations of origin, exact age and other characteristics of the donor (human or animal) are impossible due to the large number of teeth received.…”

Comparison of Knoop and Vickers surface microhardness and transverse microradiography for the study of early caries lesion formation in human and bovine enamel

“…[9][10] Data from more recent studies (employing different baseline lesions among them) highlighted very strong linear correlations between IL(Knoop) and integrated mineral loss (ΔZ) in situ 11 and in vitro, 12 although other studies did not. [13][14] The reasons for this discrepancy could be manifold, such as the mineral content and density of the surface zone, extensive subsurface demineralization, differences in mineral distribution, and presence of laminations etc.…”