| 摘要 |
<p>A filter and one-way valve for protecting a dental patient from contamination by bacteria that may be picked up by water flowing through a supply line and to prevent cross contamination of patients from the reflux of fluid from inside a patient's mouth. Several different embodiments of the invention are disclosed, including a filter/one-way valve (38) that combines a filter (42) with a one-way valve (46) in an integral assembly. This assembly is installed in a water line (34) supplying water to an air/water syringe (20), or other dental intrument, such as a dental hand piece (160), or an ultrasonic scaler. Alternatively, a separate filter is installed in the water (and/or air) line upstream of the dental instrument, and a one-way valve (140) is installed between the head of the dental instrument and a tip through which water is injected into the mouth of a patient. Furthermore, an adapter (170) that couples to a bypass circuit in which the filter/one-way valve is installed enables the benefits of the present invention to be achieved with respect to the high-speed hand piece without cutting into a line (188) through which water and other fluids are supplied to the hand piece.</p> |
