title: Cross-contamination in the dental laboratory through the polishing procedure of complete dentures.
abstract: Polishing of dental prostheses can cause a dangerous cycle of cross-contamination involving dentists, laboratory technicians, patients and auxiliary personnel. The aim of this study was to show the microbial contamination in the dental laboratory during the polishing procedure of complete dentures. For this purpose, 4 experiments were conducted. Experiment I -- Determination of the total colony-forming units (CFU) counts contaminating complete maxillary dentures. During the polishing procedure, determination of the CFU counts transferred to the operator (Experiment II) and of the total CFU counts transferred to previously sterilized complete dentures (Experiment III). Experiment IV -- The total counts of remaining CFU in the lathe spindle after Experiments II and III. Complete dentures were highly contaminated (mean = 1.4 x 10(7) CFU/mL). There was a elevated level of contamination by splatter and aerosols. There was high microbial transfer from the contaminated lathe spindle to the sterile prostheses (mean = 1.7 x 10(7) CFU/mL). The spindles were highly contaminated after polishing procedures (mean = 3.5 x 10(8) CFU/mL). The polishing of dental prostheses is a possible source of transmission of communicable diseases in the laboratory and requires improved techniques for infection control.
authors.affiliation: Department of Dental Materials and Prosthodontics, Faculty of Dentistry at Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Alessandra Marçal
authors.initials: AM
authors.lastname: Agostinho
authors.forename: Paula Regina
authors.initials: PR
authors.lastname: Miyoshi
authors.forename: Nelson
authors.initials: N
authors.lastname: Gnoatto
authors.forename: Helena de Freitas Oliveira
authors.initials: Hde F
authors.lastname: Paranhos
authors.forename: Luciene Cristina de
authors.initials: LC
authors.lastname: Figueiredo
authors.forename: Sérgio Luiz
authors.initials: SL
authors.lastname: Salvador
mesh_terms: D000328:Adult; D000368:Aged; D000391:Air Microbiology; D015169:Colony Count, Microbial; D003428:Cross Infection / Q000209:etiology*; D003748:Dental Equipment / Q000382:microbiology*; D003775:Dental Polishing / Q000009:adverse effects*; D003800:Dental Technicians; D003824:Denture, Complete / Q000382:microbiology*; D004866:Equipment Contamination; D005260:Female; D006801:Humans; D007754:Laboratories, Dental; D008297:Male; D008875:Middle Aged; D011481:Protective Clothing / Q000382:microbiology