Bacteriostatic effects of nanometer silver disinfectant on the biofilms in dental unit water lines

Abstract

Background/purpose Dental unit water lines (DUWLs) may be contaminated by aerobic bacteria in clinical settings and comprehensive disinfecting methods should be considered without delay. Herein, this study aims to investigate the timeliness and dynamic bacteriostatic effects of different forms of nanometer silver (NMS) disinfectant on bio-film in DUWLs. Materials and methods Bacterial DUWLs samples were respectively treated with different NMS forms, including liquid phase and solid phase at the concentrations of 0.25%, 0.5%, 1% and 2% and their bacteriostatic effects were observed at the 1st, 4th, 7th, 14th, 28th day. Results The bacteriostatic effects of liquid phase NMS at all concentrations were unsatisfactory and the bacteriostatic rate was only 20% at the 1st day. However, there appeared massive bacteria growth at the 4th, 7th, 14th, 28th day. Comparatively, no bacteria growth was found at the 1st, 4th, 7th, 14th, 28th day after sterilizing with different concentrations of solid phase NMS and the bacteriostatic rate was 100%. Conclusion Microbial contamination in DUWLs can be disinfected by different NMS forms, among which solid phase NMS is more bactericidal against bacteria bio-films, demonstrating significant roles of solid phase NMS in preventing DUWL contamination.

The Application of Silver to Decontaminate Dental Unit Waterlines—a Systematic Review

“…Among these articles, one paper aims to investigate the bacteriostatic effect of AgNPs on biofilm in DUWLs [ 35 ], while the purposes of other eight papers are to evaluate the efficacy of silver-based disinfectants (e.g., hydrogen peroxide/colloidal silver) or to compare the effectiveness of various commercial DUWLs disinfectants [ 3 , 33 , 36 – 41 ]. However, there was no article focusing on silver-coated dental waterlines tubing in dental water treatment.…”

“…Cheng and his coworkers [ 35 ] investigated the timeliness and dynamic bacteriostatic effects of two forms of nanometer silver (NMS) disinfectant, including liquid and solid phase, on DUWLs biofilms. They collected bacterial water samples from the stomatological department, being treated with NMS at the concentrations of 0.25%, 0.5%, 1%, and 2%, respectively.…”

“…In the studies by Cheng et al [ 35 ], Petti et al [ 37 ], and Costa et al [ 39 ], control to prevent other microbial contamination during whole research was not considered, which is an important confounding factor, and altered the results. Some included studies did not mention the sample size, such as studies conducted by Cheng et al [ 35 ], Petti et al [ 37 ], Barbot et al [ 38 ], and Costa et al [ 39 ]. Therefore, the results need further validation.…”

“…The ability of AgNPs to control oral biofilms involving specific oral pathogens since their high and broad-spectrum antimicrobial activity, as well as low drug resistance, has been demonstrated by extensive studies in dentistry [ 49 ]. Cheng et al [ 35 ] compared the bacteriostatic effect of the liquid phase and solid phase AgNPs on DUWLs biofilms. It was demonstrated that solid phase AgNPs had a stronger antibacterial effect than liquid phase one, achieving no bacteria growth at different time points.…”

Optimizing Safe Dental Practice During the COVID-19 Pandemic: Recommendations Based on a Guide Developed for Dental Practices in China

“…The pollutants, after the back suction, will be ejected again the next time they are used, which can easily cause nosocomial infections ( 91 ). Although a variety of disinfectants have been used for the disinfection of dental treatment table water system in recent years ( 92 , 93 ), it is possible to fundamentally solve the problem by using anti-suction turbo dental handpieces to prevent regurgitation. However, this will also increase the cost of oral institutions to a certain extent, and popularization and promotion may require time.…”