We probably can’t stress this point enough. Air and water to dental handpieces must be filtered. There are just too many tortuous paths which must be traveled from entry to exit for unfiltered water or air to clog up. Handpieces with multi-port spray are especially vulnerable to clogging. Change dental line filters regularly, and don’t forget to blow down moisture traps, if you have them. Most will have a little valve on bottom, which, when opened allows air pressure to cause collected water to be expelled (similar to an air compressor). This is just one more case where a little preventive maintenance, and replacing something cheap can protect your investment.