Objective: The aim of this study is to evaluate the effects of different factors, including concentration of the bacterial suspension, number of stops set on handpieces, and different disinfectants, on bacterial contamination of handpieces and their clinical significance.
Methods: Bacterial contamination of 20 handpieces were analyzed in different concentration of bacterial suspension, number of stops set on handpieces and after using different out surface disinfectants.
Results: Statistical increment (P < 0.05) of handpieces inside contamination was observed relevant to increment of the bacterial suspension concentration. No statistical relevance was seen between handpiece inside contamination and the number of stops set on handpieces(P > 0.05). Disinfection with different disinfectants significantly decreased out surface contamination(P < 0.05), but no statistical change of bacteria (P > 0.05) was observed inside handpieces.
Conclusion: As the concentration of bacterial suspension is the key factor affecting the inside contamination of handpieces, oral cavity cleanness is essential before dental therapy. The surface disinfection of handpieces is necessary after dental therapy, but cannot prevent cross-contamination between patients.