| Abstract |
Every dental unit is equipped with small-bore plastic tubing to bring water to the air/water syringe, the ultrasonic scaler, and the high-speed hand piece. Because of the formation and subsequent sloughing off of microbial biofilms from the inner surfaces of the plastic tubing, dental water is heavily contaminated with microorganisms and endotoxin. During dental procedures, the contaminated water will be aerosolized by dental equipment to spread the microbes and endotoxin into air. Dental health care personnel (DHCP) are exposed to these occupational biohazards repeatedly on a daily and long-term basis, which could cause respiratory infection, occupational asthma, and even fatality in DHCP. The long-range goal of this project is to use iodine-based rechargeable antibiofilm tubing to control the formation of dental unit waterline biofilms so as to reduce occupational exposure of DHCP to the biohazards. Iodines are one of the most widely used disinfectants in dental and hospital settings. When tested in a model dental unit waterline delivery system, we found that iodine could form complexes with polyurethane (PU) dental tubing, which are more stable and less corrosive. Thus, after complexing iodine onto plastic tubes, the new tubes were able to inactivate any approaching planktonic cells to prevent microbial adhesion/colonization, the first step in the formation of biofilms. As a result, the tubes' inner surfaces were free of biohazards during dental operations, improving the microbial quality of dental unit water and aerosols. The antibiofilm activity was stable for a reasonably long period of time (e.g., weeks), and if it was lost due to extensive use, the tubing can be easily recharged by an iodine solution flushing treatment when the dental units are not in use to regenerate the antibiofilm function. These findings shed new lights on the biofilm-control strategy in dental unit waterlines to improve the occupational safety and health of DCPs. The new materials can also be used in a wide range of related applications to fight infections. |
