Dispenser for dispensing a substance onto a substrate, such as a tooth treatment compound onto teeth, includes a vial including a pair of thin members forming a cavity therebetween in which the substance is arranged and a conduit defining an internal dispensing channel communicating with the cavity, an applicator tip arranged in connection with the conduit and including projections adapted to contact the substrate, and a cap including a cavity. The cap removably attaches to the vial and when attached, covers the applicator tip and seals the internal channel. When the cap is detached from the vial and the thin members are squeezed toward one another, the substance in the cavity is urged out of the cavity into and through the internal channel in the conduit and onto the projections to enable it to be brought into contact with the substrate.