We’ve covered maintenance of various devices in the dental office in previous issues of Tech Tips. One of the key elements of routine maintenance is filtration. Periodic replacement of filter elements is at the core of a good maintenance routine. It’s amazing how often we talk with people who don’t even know some of their filters exist, let alone take the time to maintain them. This month, we’re going to run down some of the basics of filtration and where you need to look for filters to be sure to keep your equipment running well.
Two of the most commonly overlooked filters are the air and water filters in your junction box, so look for them where the air and water come into the operatory. Every dental unit should have a master valve on the main air and water lines (the water master may be absent if you don’t have a connection to your municipal water supply). Master valves control on/off of the air or water and will almost always have a filter incorporated as well.
Two common styles of master valve are shown below:
The second master valve shown incorporates our EZ-view filter housing. Most master valves have a filter housing that is opaque, often chrome-plated, so the filter is not as obvious as it is on our valve.
As you can see in the photos, both styles of master have a filter within a cylindrical housing. Most filter elements are round or cylindrical, so look for components with that shape.
Of course, air is filtered before it gets to the junction box as well. There are both inlet and outlet filters on your compressor.
You compressor should draw in fresh air from outside. The air inlet will have a filter to remove impurities from the air. Your inlet filter should be checked quarterly and will usually need to be replaced annually.
Intake filters come in many shapes, sizes, and forms. A few examples are pictured below:
Your compressor should also have a line dryer to remove moisture from the air. While not strictly a filter, the dryer will treat the air and remove foreign bodies, much as do filters. Your dryer will also work in combination with one or more filters. You will have a water and solids particle filter and if your compressor is oil lubricated, you’ll also have a coalescing filter to remove any oil residue.
The drying tank shown above is a desiccant tank which is what we recommend. Most desiccant tanks are self-regenerating, using the compressed air to dry the desiccant beads and purging excess moisture as well. The filters that work with the tank are also self-purging so element changes should be infrequent. Nonetheless , we also recommend quarterly inspection of these filters just to be sure they are functioning properly as it doesn’t take long for problems to develop should something go wrong. There is no routine replacement schedule, however, they should be replaced strictly on an “as needed” basis.
While in your mechanical room, you should also check your central vacuum. Wet vacuums will have a filter on the water inlet. This filter is extremely important to function of a wet vacuum as debris in the water line can damage a wet vacuum pump. Clogs in this filter will also impede water flow and can thus impact your vacuum pressure reducing the effectiveness of your system. This means it’s imperative that you keep an eye on your water inlet filter. Usually debris builds up over time, so quarterly inspections should be adequate.
There will also be a particulate filter on the vacuum line feeding into the system from the ops. This helps to keep your drain lines clean and flowing well. The same type of filter is often used on both the water inlet and vacuum main lines, a simple mesh element in a clear plastic bowl to facilitate inspection.
As the above filter goes on the main water or vacuum drain lines, the inlet and outlet fittings have female pipe thread. It’s generally pretty easy to adapt from one size of pipe thread to another, but we also show pipe thread profiles at actual size in our catalog and on our web site for comparison so you can purchase a filter to match your existing pipe.
It’s important to note that there are MANY sizes of filters like this so measure what you have before purchasing a replacement. We can also cross-reference Pinnacle part numbers for our replacement filter cartridges of this type.
Anywhere in the dental office that there is air or water there should also be filtration. Don’t forget your sterilizer! Autoclaves have filters on the water line that feeds into the chamber. These filters should be changed as part of your routine annual maintenance. They can become clogged more quickly than this, however, so it’s wise to check them quarterly as well.
Most sterilizers use sintered bronze filters like the one pictured above, although many also use stainless steel screens or other filter media. Consult your owner’s manual to determine what type of filter your sterilizer uses and where it is located. If clogged you will often see debris coating the filter but it will also often become discolored, pitted, or can even crack (although this may be a sign of other problems in your sterilizer).
There are a number of critical pieces of equipment in your office that rely on pressurized air and or water, all of these have filters to remove various types of foreign matter from your lines and keep functioning well. Keep an eye on your filters to make sure your equipment keeps working well.