This paper reports all the injuries occurred from 1999 to 2011, completing data collection until 2008, previously published [12]. Although also in the previous years DS adopted procedures aimed to control crossinfections, particularly CP-690550 caused by needlestick [9], only from 1999 the procedures were standardized and a responsible for the safeness and an archive from which our data derived were created [10]. During these 13 years DS was interested in substantial and structural changes of management. The passage from a clinical to a departmental setting [13] has modified the management procedures that influenced also the planning of the clinical activity. The opening of new educational careers (M.S.

studies, high specialty courses, PhD) enlarged the areas of interest of DS to fellow dentists coming from outside; the participation to Socrates-Erasmus programme has contributed to give an international relevance to DS by means of contacts with universities with different cultural backgrounds. The transformation of the School for Dental Hygienist from 2 year diploma on first level degree (3 years) brought to an increase of the number of students exposed to occupational risk [14].The total number of incidents in the considered period was of 63, with a rate to the number of visits equal to 1 incident to 2090 visits. The number of visits was derived from the number of invoices, which are surely less than the number of visits because after some clinical procedures (suture removal, adaptation of a prosthesis, and controls) during an ongoing treatment not always an envoice is emitted.

Numerous papers have reported the incidence of injuries in dental schools [15�C19]; despite the different methods used to describe the data (incidents/year [20], rate/100 person/year [19], incidents/10000 patients visits [19], incidents/1000 activities [20], and mean number of incidents/20 days [21]) make it difficult to compare them. Table 2 reports incidence/10000 patient visits found in studies carried out in dentistry practices. Table 2Incidence of accidents in the school of dentistry.Our data do not permit to estimate the incidence rate per 100-year-person, being that the number of operators greatly varied during the period of observation. The highest number of incidents occurred in 2003 may be explained by the opening in that year of M.S. studies Brefeldin_A and high specialty courses with the consequent increase of the number of operators.