| 摘要 |
A prophylactic apparatus (100) for cleaning teeth with a flow of air containing powder particles and a flow of water which comprises a first air line (200) extending from a source of pressurized air through at least one filter to a mixing device (7), a first control device (3) arranged in the first air line for controlling the flow therethrough, the mixing device having a chamber (70) for receiving powder to be fluidized and mixed with air to form an air laden with powder particles, a nozzle (8) connected to the first air line disposed above the level of the particles, a discharge opening (9) disposed above the level of the particles in the chamber connected to a second air line (10) extending to a second nozzle opening, a second control arrangement (12) for controlling the flow of air laden with powder particles in the second air line and an arrangement for unclogging each filter by creating a backflow from at least the chamber of the mixing device and a portion of the first line. Preferably, the first control arrangement comprises a valve which enables selectively connecting the source of pressurized air to the first line and venting the first line to the atmosphere to create the reverse flow for unclogging the filters. |
