Abstract: 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 instrument, such as a dental hand piece (160), or an ultrasonic scalar. 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.

Abstract: 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 instrument, such as a dental hand piece (160), or an ultrasonic scalar. 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.

Abstract: A method and apparatus are disclosed for preventing bacterial contamination from being introduced into a dental patient's mouth from water flowing through a dental tool water line. A flexible water line typically used for supplying water to a dental syringe, high-speed hand piece, or ultrasonic scaler has been found to support and encourage the growth of a significant biofilm that serves as a source of bacteria. To prevent the bacteria from being introduced into a patient's mouth by water flowing through the line, and thus into the patient's system, an in-line water filter is installed within the water line supplying water to the dental tool, at a point adjacent thereto. Conventional Luer fittings on the in-line water filter facilitate its quick installation and replacement. In addition, a cap protects the sterility of the outlet port of the in-line water filter during the installation process.