Knowledge and practice of dental healthcare providers about disinfection of light curing units

Aims: A light curing unit (LCU) is a heat-intolerant instrument. This study aimed to assess the knowledge and practice of dental healthcare providers about the disinfection of LCUs. Methods: This cross-sectional study included 350 consented dental clinicians and clinical dental students from Dakshina Kannada district of Karnataka, India, for the questionnaire part of the study. Bacterial load and debris on the LCU tips were studied in 27 LCUs from different clinics and we studied the relationship between debris and bacterial load. Results: The survey included 334 healthcare providers. Only 51.8% agreed that LCUs should be disinfected after every patient. A significant proportion of the participants (62.3%) had no information about the type of disinfectant used in the clinic. Microorganism cultures were positive in approximately 80% of the 27 LCUs evaluated. Most of the LCU tips (67%) had visible debris. The numbers of colony-forming units (CFU)/cm² on blood agar and mitis salivarius agar were 57.94±92.28 and 28.56±40.63, respectively. Culture positivity was significantly lower on LCU with visibly clean tips (p<0.001) (0.33±7.83 CFUs/cm² on blood agar and 0.78±1.39 CFUs/ cm² on mitis salivarius agar). Conclusions: This study showed insufficient knowledge and practice in reprocessing heatsensitive semi-critical items among dental healthcare workers.