This study aimed to evaluate in vitro the pharmacological stability of the dentin biomodifiers emulsions based on copaiba oil X, at 0, 3, 6, 9, 12, 18, and 24 months, and copaiba oil Y, at 0, 6, and 12 months. The emulsions were stored in different environments and analyzed through centrifugation, pH, and density tests, as well as their organoleptic and microbiological characters were investigated. Emulsion X did not show phase separation at 0 and 6 months in the freezer and fridge and showed cleavage in all environments after 12 months. The Y emulsion did not exhibit phase separation at 0 and 6 months in the stove, fridge, room temperature protected, and exposed to light. Still, after 18 and 24 months, phase separation occurred in all analyzed environments. The emulsions X and Y did not show contamination at 12 months. In the organoleptic test, the main change observed was color. The emulsion X presented the slightest deviation of pH in the room temperature protected from light, air conditioning, and fridge while the Y emulsion at 6 months presented a smaller variation in the freezer and fridge, and at 12 months, freezer, stove, and air conditioning. Regarding density, emulsion X at 24 months showed a very slight deviation, and emulsion Y remained stable in all environments at 12 months. The emulsions tested showed stability for 12 months, with the best storage environment being the fridge. The analysis at 18 and 24 months reinforced the fridge as an ideal environment for storage.