Development and evaluation of a low erosive blackcurrant juice drink 3. Final drink and concentrate, formulae comparisons in situ and overview of the concept

Abstract

Objective: Two previous studies demonstrated that a blackcurrant juice drink with added calcium produced little erosion of enamel in vitro and in situ by comparison with other low pH fruit drinks. The primary aim of this study was to demonstrate that the final formulation drink and concentrate were of similar low erosivity. Secondary aims were to provide more data on the erosivity of other fruit drink concentrates and whether erosion was influenced by anterior and posterior palate siting of enamel specimens. Method: The study was a single centre, single blind, randomised placebo controlled 5 cell crossover design involving 15 volunteers. The test drinks were blackcurrant juice/calcium concentrate, blackcurrant juice/calcium drink, proprietary apple & blackcurrant juice concentrate, proprietary orange drink concentrate and water. Four enamel samples were retained in situ, 2 anterior palate and 2 mid/posterior palate, on upper removable acrylic appliances. Drinks were 250 ml volumes consumed 4 times per day during 15 working days. Concentrates were diluted 50 ml in 200 ml water. Measurements of enamel loss were made on one anterior and one posterior sample on days 2, 5, 10 and 15 by profilometry. Results: One subject approached the 20 μm erosion limit by day 10 on the orange drink and was withdrawn from that cell. Differences in mean erosion between anterior and posterior sites were variable and small. By day 15 the mean losses of enamel averaged over anterior and posterior were blackcurrant/calcium concentrate 0.28 μm, blackcurrant/calcium drink 0.35 μm, apple & blackcurrant concentrate 2.04 μm, orange concentrate 8.29 μm and water 0.08 μm. Except at day 15 for the blackcurrant/calcium drink the erosion by the blackcurrant/calcium formulations was not significantly different from water at any time point. Erosion by the apple & blackcurrant and orange concentrate drinks was highly significantly greater than the blackcurrant/calcium drinks at all but the 2 day time point for the apple & blackcurrant concentrate drink compared to the blackcurrant/calcium drink. Conclusions: All data thus far indicate that dependant on tooth site susceptibility and the specific drink, the consumption of standard low pH fruit drinks could result in 1mm loss of enamel in periods ranging from as little as 2 years to 20 years. Similar erosion by the low pH blackcurrant drinks with added calcium would take in excess of 100 years.