We compared the prevention of erosive and erosive/abrasive enamel loss by a medical minerals gel system (R.O.C.S.) to that by an anti-erosive toothpaste. Seventy-two bovine enamel samples were randomly allocated to six groups (E1–E3 and EA1–EA3; n=12). Per day, samples were eroded (2 min) 9 times using HCl (pH 2.6). Between erosive challenges and over night samples were stored in artificial saliva. Per day, samples were stored (100 s; groups E1–E3) or additionally brushed (20 brushing strokes; groups EA1–EA3) in/with slurries prepared from artificial saliva plus: no additional toothpaste (control groups E1 and EA1), elmex erosion protection toothpaste (groups E2 and EA2), or R.O.C.S. toothpaste (groups E3 and EA3). Once per day, samples of groups E3 and EA3 were additionally treated (40 min) with a slurry prepared from artificial saliva and R.O.C.S. medical minerals gel. After 7, 14 and 21 days enamel loss was measured by surface profilometry and analyzed by Kruskal-Wallis tests and Conover post-hoc tests. Under erosive conditions only (groups E1–E3), at each time point of measurement the significantly lowest enamel loss was observed in group E2. Substance loss in group E3 was significantly higher, but significantly lower compared to that of group E1. Under erosive/abrasive conditions (groups EA1–EA3), at each time point of measurement the significantly lowest enamel wear was observed in group EA2. Wear in group EA3 was significantly higher even compared to that of group EA1. The tested R.O.C.S. medical minerals gel system was able to reduce erosive enamel loss but not erosive/abrasive enamel wear, and it was less effective than the elmex erosion protection toothpaste.