Corrosion Behaviors of Disinfectants on Dental Unit Waterlines

To investigate the corrosion behaviors and antibacterial effects of sodium hypochlorite (NaClO) and hydrogen peroxide silver ion (HPSI) disinfectants with different concentrations against dental unit waterlines and provide guidance and reference for the use of chemical disinfectants, polyurethane tubes were immersed in ultrapure water (control group), 0.1% NaClO, 0.5% NaClO, 1.0% NaClO, 2.5% HPSI, 5.0% HPSI, and 10% HPSI solutions for 6, 12, and 18 weeks. Contact angles and Fourier transform infrared spectra were detected. Surface morphologies were observed using scanning electron microscopy and antibacterial activity was evaluated using Gram-positive Staphylococcus aureus (S. aureus). The results showed that sodium hypochlorite and hydrogen peroxide silver ion disinfectants presented good antibacterial activity against S. aureus. However, sodium hypochlorite could cause serious damage to the water pipes where corrosion pits and cracks were observed, and increasing the concentration of sodium hypochlorite could accelerate the corrosion process. Hydrogen peroxide silver ion disinfectants had no obvious damage to the water pipes. Therefore, hydrogen peroxide silver ion disinfectants are recommended to use for controlling bacterial infection in dental unit waterlines which can reduce the damage to the water pipes.