Microbial Contamination in the Waterlines of the Dental Units in Sari School of Dentistry in 2019

Microbial contamination of water sources in dental units is one of the problems in dentistry as such contamination can lead to the occurrence of dangerous infections. Given the importance of infection control and creating a healthy environment for the treatment of patients, this study conducted a microbiological analysis of water in the dental units of Sari School of Dentistry in 2019. In this descriptive-analytical and cross-sectional study, three units from each of the endodontic, restorative, surgical, pediatric, and prosthetic units of Sari School of Dentistry were randomly selected. Samples of 3-way syringe water, turbine water before and after flushing, and glass water were prepared and transferred to the microbiology department in sterile tubes. The samples were then cultured in Müller Hinton agar and blood agar and placed in an incubator at 37 °C for 24 hours. After incubation, gram staining was performed on the samples in which the bacterial colony had grown. The bacteria were examined for morphology and gram reaction. Out of 61 samples, 23 samples (37.7%) were infected with bacterial colonies. The highest frequency of bacterial infection was found in the mixed bacterial group (gram-positive cocci and gram-positive bacilli). The results of the chi-square test and Fisher's exact test showed no significant relation between the sampling site and contamination (P = 0.309). Water contamination in the pediatric and endodontic units in Sari School of Dentistry is high. Thus, effective measures should be taken to reduce water pollution in these units and reduce the risk of infection in staff and patients.