# Dose-Dependent Anti-Erosive Effect of Green Tea Extract Modification of Rivella Beverage

## TL;DR

Adding green tea extract to a soft drink reduces dentin erosion in a dose-dependent way in laboratory tests.

## Contribution

The study demonstrates that increasing green tea extract concentration in a soft drink significantly reduces dentin wear in an erosion model.

## Key findings

- Rivella with green tea extract showed significantly less dentin wear compared to unmodified Rivella.
- Dentin wear decreased almost linearly with increasing green tea extract concentration.
- The highest green tea extract concentration provided the most protection against erosion.

## Abstract

To examine the effect of adding increasing amounts of green tea extract (GTE) to a soft drink (Rivella) on dentin wear in an erosion-only model.

The study consists of two experiments: In the first experiment, a total of 60 bovine dentin samples from 4 groups (n=15) were immersed in four Rivella variants: red, blue, green, and yellow. The samples were subjected to 4 cycles (per cycle: 10 min in the specified solution followed by rinsing with deionised water for 5 sec then storage 60 min in artificial saliva). In the second experiment, a total of 120 bovine dentin samples from 8 groups (n=15) were immersed in Rivella red with modified GTE concentrations (0.0; 0.05, 0.2, 0.4, 0.8, 1.0 or 1.2%). The cycle procedure was the same as in the first experiment.  The measured dentin loss corresponded to the vertical shift on the y-axis between the baseline and the final profile after the wear process in 2D. Erosive dentin wear was measured by a stylus profilometer (µm). Data were analyzed using ANOVA followed by post-hoc pairwise comparisons and the p-values were adjusted after Holm.

In experiment 1 the following dentin wear (mean ± SD) was observed: Rivella red: 2.7 ± 0.4 µm; Rivella blue: 3.1 ± 0.4 µm; Rivella green: 2.1 ± 0.4 µm; Rivella yellow: 2.1 ± 0.3 µm. While the first two differed significantly, the last two did not.

In experiment 2 dentin wear (mean ± SD) was: Rivella+0% GTE: 3.6 ± 0.6) µm; Rivella+0.05% GTE: 3.6 ± 0.2) µm; Rivella+0.2% GTE: 3.4 ± 0.6) µm; Rivella+0.4% GTE: 3.1 ± 0.4) µm; Rivella+0.6% GTE: 2.6 ± 0.3) µm; Rivella+0.8% GTE: 2.6 ± 0.4) µm; Rivella+1.0% GTE: 2.2 ± 0.2) µm; Rivella+1.2% GTE: 2.1 ± 0.3) µm. A significant decrease in erosive wear with increasing amount of GTE was observed.

When increasing the addition of green tea extract to the soft drink Rivella, an almost linearly increasing protection against erosion can be observed in vitro.