When you sit in a dentist's chair, the water and air used during your procedure come from pipes known as dental unit waterlines. A review of 18 studies looked at these water lines to see what kind of germs live there and how they behave.
The researchers found that these waterlines often contain Gram-negative bacteria, specifically those in the Pseudomonas group. In many cases, these germs showed resistance to common antibiotics like beta-lactams, aminoglycosides, and fluoroquinolones. Some even showed multidrug resistance, meaning they can survive treatment from multiple types of drugs.
While some studies looked for specific genes that cause this resistance, data was limited because only two studies checked for them. The review also noted that fungi living in the water's biofilm were harder to treat than those floating freely. Because these germs are already showing signs of resisting medicine, researchers suggest more study is needed to track both their physical traits and their genetic makeup.
