3 种消毒剂对超声洁牙机单元水路的消毒效果研究.

Objective  To assess the efficacy of three disinfectants in disinfecting the ultrasonic scaling unit waterline.   Methods  Twelve periodontal ultrasonic scalers were randomly divided into four groups based on the disinfection protocol: distilled water (A group), 3% hydrogen peroxide (B group), 500 mg/L chlorine disinfectant (C group) and 5% povidone-iodine (D group). Each scaler was used for daily periodontal treatment and worked effectively for 6 hours per day. Water samples were collected at baseline, after disinfection, and 1-7 days post-disinfection. Scanning electron microscopy (SEM) was used to observe biofilm formation. Culturable bacteria were counted, isolated and purified, then identified through 16S rRNA gene sequencing. Sequences of 16S rRNA gene amplicons were clustered by operational taxonomic units (OTUs).  Results  Baseline colony counts exceeded 100 CFU/mL in all groups. However, after disinfection, the colony counts decreased significantly in all groups (P < 0.05). The colony counts remained below 100 CFU/mL within 3 d after disinfection with 3% H2O2, within 6 days after disinfection with 500 mg/L chlorine-containing disinfectant, and within 4 d after disinfection with 5% povidone-iodine (P < 0.05).Pathogens such as Stenotrophomonas maltophilia were detected in the ultrasonic scaler unit water circuit. SEM showed thinner biofilm thickness in the 3% H2O2 and 5% povidone-iodine groups compared to the control group (P < 0.05).  Conclusions  Bacterial contamination is present in the ultrasonic scaling unit waterline, posing a potential infection risk to periodontal staff and patients. In the context of increasingly severe nosocomial infections, appropriate disinfection protocols should be developed based on clinical realities. [ABSTRACT FROM AUTHOR]