[312604]
Rptr believes they have a ongoing problem with cross contamination with existing dental evacuation systems. When the vacuum system was implemented it allowed them to comfortably sit down with the pt lying back -ergonomics-. Rptr spent less time waiting for the pt to spit and rinse making them more efficient. However, the resulting position of the pt creates a situation with the vacuum tip, valve and a portion of the hose sloped down into the pt's mouth. The high volume evacuators or saliva ejectors are safe unless flow is interrupted, constricted or reversed by a vacuum created in the pt's mouth. Maybe a false assumption exists that the vacuum will hold water in a static position in the hose when flow is interrupted. If flow is interrupted gravity will take over resulting in water running backward from the highest point in the vacuum hose to the lowest point, the pt's mouth. Rptr learned from science class in grade school that if a rock and a feather are dropped in a vacuum they will both hit the ground at the same time. Any water above the replaceable vacuum tip will be contaminated and will drop back into the sterile vacuum tip contaminating that plus the pt's mouth. Rptr goes to great lengths to make sure the delivery system is safe for the pt with attention to sterilization and now even biofilms in their units. Rptr feels they are ignoring the filthiest area in the delivery system. Interrupted or constricted flow occurs if the tongue or cheek is drawn into the vacuum tip, something blocks the hose or the amalgam trap becomes full. The likelihood of the amalgam trap being blocked/constricted is not great unless it is not properly maintained or they generate a lot of debris in a day. It happens! Large tooth fragments or old restorations, maybe a root tip, fractured cusp or chunk of amalgam can block the hose or valve. The hose or valve may block once or twice a month. The vacuum tip can be blocked with the tongue, cheek, or lip. This will likely happen several times a day. The pump may quit. Backflow in the system will occur if the vacuum in the pt's mouth exceeds the vacuum in the hose. Rptr asks every pt to spit into the vacuum tube. Most of them don't have a place for the pt to spit even if they want to. Rptr tried to find required specs on vacuum systems but it seems the mfrs have set the standard. The profession should have guidelines. The average system pressure is set at 5-10 inches of mercury. A near total vacuum is 30 inches of mercury or 34 feet of water. Every pump is different. Five inches of mercury will lift 5. 5 feet of water -68 inches-. Rptr knows of one office that uses a wet and dry vacuum that will lift 3 feet of water. Rptr has a surge pump set at 10+ inches of mercury with a high volume output -a real muscle pump-. This pump lifts 12+ feet of water -144 inches-. However, the vacuum varies depending on how may operators are drawing on the system and how far away users are from the pump. Rptr has four drs in their clinic, five hygienists and one expanded duty assistant. If the valves on all ten are opened and rptr goes to the far end of the line vacuum draw is 49 inches. Now, rptr can hold 2+ ounces of water in their mouth, which will fill 30 inches of hose - the height of the amalgam trap from the floor-. That lowers the vacuum to 19 inches of water. Rptr can lift 96 inches of water -7 inches of hg- with their mouth. The 96 inches would be the kind of pressure needed to draw out a thick malt. The possibility of overpowering the vacuum under normal conditions is unlikely. Drawing 49 inches of water is different but very doable. The 49 inches -3. 6 hg- would be the consistency of somewhat thinner malt. The 19 inches of water is certain to be overpowered with a suck. The 19 inches -1. 4 hg- is approaching the vacuum needed to sip a soft drink with a straw. Chances of all valves being open at the same time may happen a couple times a day. What amount of risk is acceptable? If backflow is possible you can bet it will happen. Rptr worries about biofilms in units. They discuss throwing away instruments after seeing pts infected with prions. Options for solving the problem are few. The medical profession use closed vacuum systems with new tips, tubing and collection bottle. Throw away the hose. Swivels are impossible to take apart, therefore, impossible to sterilize. Then would have to replace the hose. This would all be labor intense and again would be very expensive. Mechanical check valves are complex, impossible to sterilize and unreliable while still leaving the area above the valve contaminated and a threat to the pt. Rptr could always go back to the cuspidor. Rptr doesn't think they could stand to have vacuum systems taken away. Losing the use of the vacuum would be catastrophic to the profession. Working standing up again would probably cut what they can do by one half. Rptr has an idea for a disposable trap/check valve that would solve the problem.
Patient Sequence No: 1, Text Type: D, B5