serological examination to ascertain infection by HVB, HVC, HIV of the patient involved. 2.1. Statistical AnalysisUnivariate techniques were used to describe the data: frequency distribution and pie-chart for nominal variables, median and range for quantitative variables, and column chart for the prevalence of accident GNF-5? per year. ��2 test was used to evidence the associations between nominal variables. Bivariate linear regression was used to demonstrate the presence of a trend between the number of patient visits and the number of accidents; the association between the two variables was verified by means of Spearman’s rho coefficient. �� level was a priori set at 0.05. 3.

Results There were 63 incidents within DS from 1999 to 2011 and 131699 patient visits (the minimum patient visits in 1999 was 8661 and the maximum in 2007 was 117199 with a mean of 10131 treatments per year); the rate between the number of incidents to the number of visits was of 1 injury to 2090 visits; the incidence/10000 visits �� standard error was 4.78 �� 0.60 all over the period considered. The number of operators involved was 61, 28 males (45%) and 33 females (55%); no significant difference was observed between sexes. Double injuries occurred to 2 operators were of different types and happened in different times.The age of the damaged operators was between 19 and 60 years (median age: 26 years). 40% of those involved in the accidents were students and 36% dentists attending M.S. and PhD studies (Figure 1).Figure 1Percentage of accidents by operator category.

Considering the number of injuries per year (Figure 2(a)) it emerges that it reaches a peak in 2003 (9 injuries) and the minimum level in 1999 (1 injury). It is interesting to observe that the number of clinical activities increases proportionally from 1999 to 2011 (p = 0.0001) (Figure 2(b)) while the number of injuries does not GSK-3 follow this trend (p = 0.6409). No statistically significant association is observed between the number of clinical activities and the number of injuries (p = 0.217).Figure 2The highest number of injuries happened in June and November (n = 8) and the minimum in July and December (n = 3).