Evacuation Line Maintenance

Waterline Treatment

Clean evacuation lines ensure that suction lines are safe and fully functioning. Proper maintenance requires only a small time investment on the part of the dental staff. By consulting with the manufacturer to ensure proper cleaning protocols are followed and the right cleaning products are used, suction lines will remain free of debris build-up, the suction flow will be uninterrupted and patients will receive the best possible care.

Safe and economical
In recent years, more cleaners have become available that feature a neutral pH, making them compatible with the office’s amalgam separator. Natural ingredient-based products have also been introduced and will be further evaluated for use in the next several years.

Still, some dentists have been reluctant to use them, objecting to the time investment and the risk of spillage. There has also been some objection to the cost of the cleaner and the need to adjust to a new dosage when switching to a new product. However, cleaning suction lines daily for both dry and wet vacuum systems is necessary to remove and prevent debris build-up and ensure proper suction flow.

When cleaners are used appropriately, they provide a safe, economical solution. For instance, the use of a non-foaming cleaner generally is recommended for use with dry vacuums, as foam cleaners tend to leave the turbine coated with residue and debris, leading to lower performance, loss of suction and eventual pump failure.

Dental providers should be aware of CDC recommendations to keep suction lines disinfected daily in case backflow occurs when using a saliva ejector. For more information visit https://www.cdc.gov/oralhealth/infectioncontrol/faq/saliva.htm.

In addition, they can refer to the book Infection Control and Management of Hazardous Materials for the Dental Team, which states:

High-volume evacuation (HVE) during the use of rotary equipment and the air/water syringe greatly reduces the escape of salivary aerosols and spatter from the patient’s mouth, which reduces contamination of the dental team and nearby surfaces. One should clean the HVE system at the end of the day by evacuating a detergent or water-based-detergent disinfectant through the system. One should not use bleach (sodium hypochlorite) because this chemical can destroy metal parts in the system. One should remove and clean the trap in the system periodically. A safer approach, however, is to use a disposable trap. These traps may contain scrap amalgam and should be disposed of properly. The dental team member must wear gloves, masks, protective eyewear and protective clothing when cleaning or replacing these traps to avoid contact with patient materials in the lines from splashing and direct contact. Disinfection of the trap by evacuating some disinfectant-detergent down the line, followed by water, is best before one cleans or changes the trap.

Resource: Miller CH. Infection Control and Management of Hazardous Materials for the Dental Team, 5th edition. Elsevier/Mosby Publishers. Page 181.

Editor’s note: Sponsored by Air Techniques


Dental effluent guidelines

Mercury pollution is widespread and a global concern that originates from a number of sources, including dental offices. In fact, dental clinics are considered to be the main source of mercury discharges to publicly owned treatment works (POTWs), according to the Environmental Protection Agency (EPA). According to EPA estimates, approximately 103,000 dental offices use or remove amalgam in the United States, and almost all of these send their wastewater to POTWs. Furthermore, dentists discharge approximately 5.1 tons of mercury each year to POTWs, most of which is subsequently released to the environment.

Mercury-containing amalgam wastes generally find their way into the environment when new fillings are placed or old mercury-containing fillings are drilled out and waste amalgam materials that are flushed into chair-side drains enter the wastewater stream. Mercury entering POTWs frequently partitions into the sludge – the solid material that remains after wastewater is treated. Mercury from waste amalgam therefore can make its way into the environment from the POTW through the incineration, landfilling or land application of sludge, or through surface water discharge.

Amalgam separators are regarded as a practical, affordable, available technology for capturing mercury and other metals, before they are discharged into sewers that drain to (POTWs). Once captured by a separator, mercury can be recycled.

In July 2017, the EPA passed its final rule specific to Best Management Practices for Dental Amalgam Waste, prohibiting the use of bleach or chlorine-containing cleaners that may lead to the dissolution of solid mercury when cleaning chair-side traps and vacuum lines. The rule says, “…vacuum lines that discharge amalgam process wastewater to a POTW [publicly owned treatment works] must not be cleaned with oxidizing or acidic cleaners, including but not limited to bleach, chlorine, iodine and peroxide that have a pH lower than 6 or greater than 8.” (40 CFR 441.30(b)(2)).

EPA expects compliance with this final rule will reduce the discharge of mercury by 5.1 tons each year, as well as 5.3 tons of other metals found in waste dental amalgam to POTWs. For more information visit the EPA website: https://www.epa.gov/eg/dental-effluent-guidelines.

Editor’s note: Sponsored by Air Techniques.