I have seen manufacturers of dental handpieces claim that anti-retraction valves prevent disease. How is that possible?

Dental handpieces are required to have approved anti-retraction valves, which prevent contaminated fluids such as saliva from being sucked back into the handpiece. These valves are designed to stop retraction of resilient, pathogenic bacteria in oral fluids. For example, the manufacturer of NSK handpieces includes a description of the Clean Head System in its product brochure. This section reads: “The NSK patented Clean Head System prevents fluid and debris from being retracted into the head of the handpiece, prolonging bearing life and enhancing infection control.” NSK would not be able to include this statement in their product material without testing and FDA approval.