1995 Volume 45 Issue 2 Pages 243-256
In order to identify the distribution of air pollution in dental hospitals, airborne bac teria, airflow, and number of persons were measured in orthodontics, pedodontics, restoration, and prosthetics clinics at Asahi University dental hospital for 2 years. Airborne bacteria were detected at five spots in each dental clinic with an SY type pinhole sampler method (SY method) and Koch's dropping method (Koch method). Chronological changes in number of airborne bacterial colonies and distribution in number of airborne bacterial colonies at the five measuring spots in the clinics were evaluated by two-way analysis of variance. Cluster analysis was performed to classify the five measuring spots in the clinics according to factors of airborne bacterial colonies estimated with the SY method and the Koch method. Correlation between the personal movement factor and the number of airborne bacterial colonies were also evaluated. The following results were obtained ; 1. The airborne bacterial count was from 0,02 to 1.42 colony-forming units (CPU) per liter with the SY method and 0.08 to 6.83 with the Koch method in the clinics, and it was found that the distribution of the airborne bacterial count varied with the seasons. 2. According to the two-way analysis of variance, the measuring spots showed difference of airborne bacterial count in each clinic. Thus, a number of measuring spots are necessary to obtain a realistic bacterial count. 3. The five measuring spots were classified into two groups by cluster analysis. Cluster analysis is a useful method to identify the distribution of the number of airborne bacterial colonies and to select measuring spots in dental clinics. 4. The correlation between the personal movement factor and the number of airborne bacterial colonies in dental clinic was highly significant (P <0.01).
