Bacterial contamination of curing light guides: prevalence and students’ knowledge and awareness of measures to maintain sterility

It is generally accepted that inadequately sterilized dental curing light guides pose risks of infection and cross contamination.To determine the presence and level of bacterial contamination among curing light guides used by students during patient care at a dental school in South Africa and to describe students’ knowledge and awareness of measures used to maintain their sterility. A two-part descriptive study consisting of microbiological testing and a cross-sectional survey. Swabs were collected from curing light guide tips before and after use for aerobic culture and a questionnaire was used to collect data pertaining to students’ knowledge and awareness of measures used to maintain their sterility. The prevalence of contamination increased after use (54.5% vs 45.5%). Grades of bacterial growth higher than 1+ were not detected. Isolated bacteria were contaminants. The response rate for the questionnaire was 42.5%. Fifth-year students were overall more knowledgeable than fourth-year students (81.6% vs 67.5%) and were more aware of the existence of the different types of disposable barriers (27.5% vs 12.8%) and the impact of infection control barriers on curing light intensity (52.4% vs 15%). Contamination occurred despite high levels of knowledge and awareness of the risk.