Sieber KR, et al. - Considering the enhancement of erosion-protective properties of the pellicle when casein and mucin are applied in combination, researchers conducted this in vitro study optimizing the concentrations of these 2 proteins to achieve a maximum protective effect. they conducted this study in 2 parts; a total of 195 human enamel specimens were prepared and were randomly assigned to 13 groups, corresponding to 11 different casein-mucin concentration-combinations tested and 2 negative control groups (humid chamber). As per results, the highest erosion-protective effect was achieved with concentration combination of 3.0% casein and 0.81% mucin. As measured by SMH as well as SRI, this concentration led to a significant protection compared to the unmodified pellicle.