A tooth treatment applicator includes a rod member having a distal portion with a hollow interior and an applicator tip assembly comprising an attachment rod received within the hollow interior and a tip member coupled to the attachment rod. A portion of the distal portion of the rod member is deformed to secure the attachment rod within the hollow interior. In some embodiments, the deformation may be formed by heat staking and may include one or more deformed portions that create an interference between the rod member and the attachment rod. The applicator may be used with a container holding a composition, such as a tooth whitening composition comprising hydrogen peroxide and alcohol. In some embodiments, alcohol in the composition evaporates during use, and composition on the applicator tip that has begun to harden due to evaporation is re-dissolved when the applicator tip is returned to the container.