Qualitative and Quantitative Evaluation of the Microflora in Dental Unit Waterline of Dental Clinics in Mangaluru: A Cross-sectional Study

Aim: The presence of microbial contaminants in the dental unit waterline poses a potential risk for both patients and healthcare personnel. This study aimed to conduct a qualitative and quantitative assessment of the microflora in the dental unit waterline of dental clinics in Mangaluru city. Methods: Water samples were collected from a total of 16 private dental clinics across Mangaluru. For the quantitative assessment, bacterial counts were determined using standard culture media, and the automated identification of the isolated bacterial species was done for qualitative assessment. Following the standards proposed by the United States Centers for Disease Control and Prevention (CDC) and the American Dental Association (ADA), grading was done as a bacterial count below 500 CFU/mL was classified as unsatisfactory. The data was recorded, and statistical analysis was performed on the same. Results: The bacterial counts were found to range between 37 CFU/mL and 690 CFU/mL. The majority of isolated microorganisms included Bacillus species, Pseudomonas species, and non-fermenting Gram-negative bacilli. Although most tested samples had bacterial counts within acceptable limits, the various isolated bacterial species emphasized their ability to cause potential health hazards even at lower concentrations. Conclusion: The findings of this study indicate that there were no major microbial contaminants in the dental unit waterline of dental clinics in Mangaluru. However, the presence of varied microorganisms, even though in low concentrations, raises the threat of potential contamination. Clinical significance: This study indicates that the presence of fewer, yet varied concentrations of microbes can still pose the threat of contamination, and hence it underscores the need for regular supervision and disinfection of the dental unit waterlines in routine clinical practice.