There are a lot of different systems and components used in a dental office. However, few are used as more frequently in almost all types of dental procedures than the foot control.
Dental foot controls can be designed for use for both wet and dry applications, and they also play an essential role in regulating the pressure that controls the volume of air or water at the handpiece. Without a correctly functioning foot control, it is possible to have a variance of as much as 20 to 30 pounds per square inch at the handpiece. To correct this, a regulator valve is used to manage the pressure when the control is depressed, resulting in an even 40 or so pounds of pressure. When the foot is removed, the valve shuts and releases, eliminating the flow of air through to the handpiece.
Chip Air and Water Regulation
Some dental foot controls also come with a chip blower or a pilot air valve. This is a separate line that runs from the control to the chip air control on the handpiece. This provides an additional level of air to move chips or debris and, like the standard air regulation, the pressure is controlled by depressing the foot control.
The pilot air valve in dental foot controls is also the controller for the water supply. The air pressure from the pilot air valve moves a toggle valve that opens up to allow water to the handpiece. As soon as the foot control is released by the operator, the toggle valve immediately shuts due to lack of air pressure in the line, allowing for the immediate stop of water at the handpiece.
Without this, or if the valve is failing, water will drip or dribble out after the foot is released. Problems with the pilot air valves as well as the regulator valve can result in low air pressure, irregular pressure or constant leaking of air after the foot is removed from the control.