Bell-Ans; Soda Mint 

painfull noncontagious sores that form inside the mouth and on the lips

Sodium bicarbonate (NaHCO3), or sodium hydrogen carbonate, also known as baking soda and bicarbonate of soda, is a soluble white anhydrous or crystalline compound, with a slight alkaline taste resembling that of sodium carbonate. It is found in many mineral springs and also produced artificially.

Canker Sores as related to Sodium Bicarbonate