I read with interest the article by Malekshoar et al (Malekshoar M, Malekshoar M, Javanshir B. Challenges, limitations, and solutions for orthodontists during the coronavirus pandemic: a review. Am J Orthod Dentofacial Orthop 2021;159:e59-e71).
They correctly point out the importance of paying attention to the cleaning of the waterlines as part of a dental clinic’s disinfection process while dealing with potential severe acute respiratory syndrome coronavirus contamination. However, the advice that they give for disinfecting dental unit waterlines (DUWLs), which they attribute to previous work undertaken by me, is wholly incorrect and, if followed, would significantly jeopardize a clinic’s cross-infection control efficacy, to the detriment of both patients and staff alike, even in the absence of a pandemic.
They state that “Flushing water lines for at least 2 minutes at patient intervals or sucking about 1 L of 1% sodium hypochlorite through the suction line at the end of the day controls the dental unit water and reduces infection risks, 90,91 ” in which the citations 91 and 90 in support of these statements purportedly relate to my previous publications, , respectively.
In fact, these published clinical audits investigated the effect a number of disinfectants had when coursed through DUWLs on a continuous basis, on both the elimination of any adherent biofilms and on the suspended planktonic bacterial water contamination, in contrast to the simple purging of the waterlines alone, without the use of any disinfectants.
Both these studies showed that unlike the continuous use of a DUWL disinfectant, the latter expedient of simply purging the waterlines on their own was completely useless at rendering water qualities for the irrigation of dental drills, ultrasonic scalers, or 3 in 1 air-water syringes that would satisfy either the Centers for Disease Control and Prevention’s recommendation of attaining the U.S. Environmental Protection Agency’s drinking water standards, or that of the more stringent European Union standard for potable (drinking) water.
In contrast, the very opposite was found to be the case, as bacterial counts were increased because of portions of the biofilms becoming detached and sloughing off into the water during the process. ,
In relation to their recommendation that a dental chair unit’s suction lines should be disinfected with a liter of 1% sodium hypochlorite at the end of the day, but again, their reference to my publications is unwarranted because my published research only dealt with the disinfection of DUWLs.
Instead, wide bore, sterilizable tubes for high volume suction lines and single-use, disposable saliva ejectors for low volume suction lines should be used, with disinfection of these suction lines twice a day, both at the end of the morning and the afternoon clinic sessions, using a nonfoaming disinfectant that has been both formulated and approved for this purpose.
1. Chate R.A.C.: An audit improves the quality of water within the dental unit water lines of three separate facilities of a United Kingdom NHS Trust. Br Dent J 2006; 201: pp. 565-569.
2. Chate R.A.C.: An audit improves the quality of water within the dental unit water lines of general dental practices across the East of England. Br Dent J 2010; 209: pp. E11.
3. Coleman D.C., O’Donnell M.J., Boyle M., Russell R.: Microbial biofilm control within the dental clinic: reducing multiple risks. J Infect Prev 2010; 11: pp. 192-198.
4. Fulford M.R., Stankiewcz N.R.: Dental disinfection and environmental decontamination.2019.SpringerCham, Switzerlandpp. 105-115.