| 摘要 |
A tray, 1, for dental use comprises at least one dam or protrusion, 2, 3, on the tooth-facing surface of the tray to limit, in use, the spread of a composition placed in the tray. In particular the composition is a whitening agent and the dam faces the front surface of the teeth, preferably at the gingival margin. The dam, 3, facing the rear surface is preferably remote from the gingival margin. Also described are methods for making the tray and a model used for making the tray. |
