Dental impressions for prosthetics are a vector of contamination due to contact with the mucus and serous fluids of the oral cavity. The objective of this work was to assess the knowledge and practices of dental prosthesis practitioners regarding contamination via impressions in the dental office and in the dental prosthesis laboratory. This was a descriptive cross-sectional study of 40 volunteer practitioners who take or manipulate dental impressions in dental prosthesis offices and laboratories in the district of Bamako. Statistical analysis was performed using SPSS statistics version 25.0 software. The male sex represented 82% of cases with an average seniority of 8.75 years. Private structures accounted for 60% of cases. Dental offices accounted for 82% of cases. Alginate was used as impression material in 97.5% of cases. Rinsing with water as a decontamination method was used in 42% of cases. Sodium hypochlorite was used as a disinfectant in 25% of cases. The training of the actors of the prosthetic chain, the development of the procedures of the decontamination and individual protection of each prove to be essential.