A composition (C) for use in dentistry and an apparatus (1) for the treatment of the oral cavity, comprising: a containing compartment (2) that contains the composition (C) in the liquid state； a duct (3) for discharging the composition (C) configured to generate a flow (F) at a given discharge pressure； and a delivery valve (4) interposed between the containing compartment (2) and the discharge duct (3), said valve (4) being switchable between a delivery condition in which it places the compartment (2) in fluidic connection with the duct (3) to permit the passage of a predefined amount of the composition (C), and a closed condition in which it does not permit the passage of the composition (C) between the compartment (2) and the duct (3)； the composition comprises 10-15% in weight of sodium bicarbonate and water at 100% in weight.
