title: Importance of rotary systems in dental care by undergraduate students in patients of a public health service of Belo Horizonte.
abstract: BACKGROUND
  The aim of this study was to evaluate the fracture rates of ProTaper rotary files used in the endodontics extension clinic of the Undergraduate Dentistry Course of the Pontifical Catholic University of Minas Gerais during the prior eight years.
  
  
  METHODS
  Control record data regarding file usage by students were collected and analyzed by semester. For each period, the total number of patient consultations, the frequency of file use, the occurrence of fractures and the file numbers for which fractures occurred were noted. Descriptive statistics, including frequency of file fractures were calculated for all file types. The chi-square test was used to evaluate differences in the frequency of file fractures between all file types.
  
  
  RESULTS
  The study results revealed that during the examined period, there were 1006 consultations and 7993 uses of files. A total of 30 file fractures were recorded throughout this period; thus, fractures occurred in 0.37% of total file uses and 2.98% of all consultations. The most frequently used files were S1, S2 and F1, and these files also accounted for the most fractures. However, no differences in the frequency of file fractures were observed between the file types (p𰀎0.05).
  
  
  CONCLUSIONS
  The low fracture rates observed in this study indicate that the examined instruments can be used to safely provide dental care to patients.
  
  
  BACKGROUND
  Dental instruments, endodontics, public health.
authors: DDS, MS, Graduate student, Departament of Dentistry, Pontifícia Universidade Católica de Minas Gerais, Belo Horizonte, Brasil.
authors: Fernanda-Alcaraz-Orta
authors: FA
authors: Bruno
authors: DDS, MS, PhD, Professor, Departament of Dentistry, Pontifícia Universidade Católica de Minas Gerais, Belo Horizonte, Brasil.
authors: Eduardo
authors: E
authors: Nunes
authors: DDS, MS, PhD, Professor, Departament of Dentistry, Pontifícia Universidade Católica de Minas Gerais, Belo Horizonte, Brasil.
authors: Martinho-Campolina-Rebello
authors: MC
authors: Horta
authors: DDS, MS, Professor, Departament of Dentistry, Pontifícia Universidade Católica de Minas Gerais, Belo Horizonte, Brasil.
authors: Ana-Maria-Abras
authors: AM
authors: da Fonseca
authors: DDS, MS, PhD, Professor, Departament of Dentistry, Pontifícia Universidade Católica de Minas Gerais, Belo Horizonte, Brasil.
authors: Frank-Ferreira
authors: FF
authors: Silveira