Rptr believes this "prophy-jet" device poses a serious threat to pts because of a design flaw in the air pressure regulator. The prophy-jet sprays a slurry of air, water and baking soda onto the teeth to polish them. The air pressure regulator has malfunctioned several times during use, causing air and baking soda to be forced into the pt's mouth at very high pressure. This can easily cause an emphysema of the soft tissues and can dissect between the tooth and gum into the facial planes of the head and neck, with disasterous consequences.

Add'l info rec'd from mfr 8/10/01: repair completed. November 2000 issue: too much air pressure. Tech found that one operatory did not have an office air pressure regulator. The air into the operatory was at 120 psi (beyond the 65-100 psi air line requirements listed in the g113 dfu). The tech installed an air regulator in the operatory, set at 80 psi. (note: excess air pressure to the operatory could give the perception of excess air through the g113 handpiece when the unit is moved from operatory to operatory without changing the unit settings. ) examination of the instrument design shows that the external air supply enters the rear of the instrument through a pneumatic fitting. The air passes through a solenoid control valve and into the air pressure regulator. The output of the air pressure regulator is the sole source of pressurized air distributed to other components within the instrument. A risk analysis was performed for the air pressure regulator. The outcome of the analysis indicated one failure mode that could potentially cause a safety concern for the pt. The risk factor would be potentially caused by two concurrent failures: a foreign particle entering the system from the office air system and forcing the regulator to open at the same time as a malfunction to the office compressor, resulting in abnormally high air pressure. However, the probability of occurrence is rated low and the probability of detection is rated high, leading to a risk priority that is low and well below the threshold for corrective action. No complaints have been received and no repairs have been completed on the g113 unit for the air regulator or air pressure system, which was identified as high air pressure reaching the pt from 1998 thru 7/01 (the period that the complaint report system contains a breakdown of failures by component. ).