title: Microbial environmental contamination in Italian dental clinics: A multicenter study yielding recommendations for standardized sampling methods and threshold values.
abstract: A microbiological environmental investigation was carried out in ten dental clinics in Italy. Microbial contamination of water, air and surfaces was assessed in each clinic during the five working days, for one week per month, for a three-month period. Water and surfaces were sampled before and after clinical activity; air was sampled before, after, and during clinical activity. A wide variation was found in microbial environmental contamination, both within the participating clinics and for the different sampling times. Before clinical activity, microbial water contamination in tap water reached 51,200cfu/mL (colony forming units per milliliter), and that in Dental Unit Water Systems (DUWSs) reached 872,000cfu/mL. After clinical activity, there was a significant decrease in the Total Viable Count (TVC) in tap water and in DUWSs. Pseudomonas aeruginosa was found in 2.38% (7/294) of tap water samples and in 20.06% (59/294) of DUWS samples; Legionella spp. was found in 29.96% (89/297) of tap water samples and 15.82% (47/297) of DUWS samples, with no significant difference between pre- and post-clinical activity. Microbial air contamination was highest during dental treatments, and decreased significantly at the end of the working activity (p<0.05). The microbial buildup on surfaces increased significantly during the working hours. This study provides data for the establishment of standardized sampling methods, and threshold values for contamination monitoring in dentistry. Some very critical situations have been observed which require urgent intervention. Furthermore, the study emphasizes the need for research aimed at defining effective managing strategies for dental clinics.
authors.affiliation: Dipartimento di Sanità Pubblica, Università degli Studi di Parma, Italy. ira.pasquarella@unipr.it
authors.forename: Cesira
authors.initials: C
authors.lastname: Pasquarella
authors.forename: Licia
authors.initials: L
authors.lastname: Veronesi
authors.forename: Christian
authors.initials: C
authors.lastname: Napoli
authors.forename: Paolo
authors.initials: P
authors.lastname: Castiglia
authors.forename: Giorgio
authors.initials: G
authors.lastname: Liguori
authors.forename: Rolando
authors.initials: R
authors.lastname: Rizzetto
authors.forename: Ida
authors.initials: I
authors.lastname: Torre
authors.forename: Elena
authors.initials: E
authors.lastname: Righi
authors.forename: Patrizia
authors.initials: P
authors.lastname: Farruggia
authors.forename: Marina
authors.initials: M
authors.lastname: Tesauro
authors.forename: Maria V
authors.initials: MV
authors.lastname: Torregrossa
authors.forename: Maria T
authors.initials: MT
authors.lastname: Montagna
authors.forename: Maria E
authors.initials: ME
authors.lastname: Colucci
authors.forename: Francesca
authors.initials: F
authors.lastname: Gallè
authors.forename: Maria D
authors.initials: MD
authors.lastname: Masia
authors.forename: Laura
authors.initials: L
authors.lastname: Strohmenger
authors.forename: Margherita
authors.initials: M
authors.lastname: Bergomi
authors.forename: Carola
authors.initials: C
authors.lastname: Tinteri
authors.forename: Manuela
authors.initials: M
authors.lastname: Panico
authors.forename: Francesca
authors.initials: F
authors.lastname: Pennino
authors.forename: Lucia
authors.initials: L
authors.lastname: Cannova
authors.forename: Marialuisa
authors.initials: M
authors.lastname: Tanzi
mesh_terms: D000391:Air Microbiology; D003740:Dental Clinics; D003748:Dental Equipment / Q000382:microbiology; D004784:Environmental Monitoring / Q000592:standards*; D004866:Equipment Contamination; D006801:Humans; D007558:Italy; D020711:Threshold Limit Values; D014871:Water Microbiology