Abstract: A hand-held dental instrument for intraoral abrading of teeth includes a light-weight body made from a high temperature material and having internal bores or passageways for permitting fluid flow through the body. A rotatable nozzle assembly having internal fluid conduits therein is coupled to a distal end of the body such that a chamber is formed between the nozzle and the body. The chamber maintains fluid communication between an internal bore which is radially offset from a central axis bore of the body and an internal conduit of the nozzle assembly such that the nozzle can be rotated a full 360 degrees with respect to the body. The nozzle assembly includes a primary discharge port for directing flow of the air/abrasive material mixture and a secondary discharge port for directing a stream of liquid to a surface to be abraded.

Abstract: A hand-held dental instrument for intraoral abrading of teeth includes a light-weight body made from a high temperature material and having internal bores or passageways for permitting fluid flow through the body. A rotatable nozzle assembly having internal fluid conduits therein is coupled to a distal end of the body such that a chamber is formed between the nozzle and the body. The chamber maintains fluid communication between an internal bore which is radially offset from a central axis bore of the body and an internal conduit of the nozzle assembly such that the nozzle can be rotated a full 360 degrees with respect to the body. The nozzle assembly includes a primary discharge port for directing flow of the air/abrasive material mixture and a secondary discharge port for directing a stream of liquid to a surface to be abraded.

Abstract: A transfer pad in which a central sump is covered with a liquid-impervious membrane. A layer of gravel is then added on top of the membrane. To facilitate monitoring and draining of the pad, a network of perforated pipes is installed within the gravel layer to receive liquids that have filtered through the layer. The gravel layer is then partially covered with concrete, onto which a truck may drive. The layer of gravel may be further covered with a permeable buffer on top of which is added a second layer of gravel. The concrete would then be placed on top of the second layer of gravel. Materials spilled onto the concrete portions of the slab or the gravel are percolated through the gravel layers and collected within the perforated pipes.