title: Radiographic technical quality of root canal treatment performed ex vivo by dental students at Valencia University Medical and Dental School, Spain.
abstract: OBJECTIVE
  To evaluate radiographically the quality of root canal fillings and compare manual and rotary preparation performed on extracted teeth by undergraduate dental students.
  
  
  METHODS
  A total of 561 premolars and molars extracted teeth were prepared using nickel-titanium rotary files or manual instrumentation and filled with gutta-percha using a cold lateral condensation technique, by 4th grade undergraduate students. Periapical radiographs were used to assess the technical quality of the root canal filling, evaluating three variables: length, density and taper. These data were recorded, scored and used to study the "technical success rate" and the "overall score". The length of each root canal filling was classified as acceptable, short and overfilled, based on their relationship with the radiographic apex. Density and taper of filling were evaluated based on the presence of voids and the uniform tapering of the filling, respectively. Statistical analysis was used to evaluate the quality of root canal treatment, considering p < 0.05 as a statistical significant level.
  
  
  RESULTS
  The percentage of technical success was 44% and the overall score was 7.8 out of 10. Technical success and overall score were greater with rotary instruments (52% against 28% with a manual one, p < 0.001; 8.3 against 6.7 respectively, p < 0.001).
  
  
  CONCLUSIONS
  It appears that inexperienced operators perform better root canal treatment (RCT) with the use of rotary instrumentation.
authors.affiliation: Facultat de Medicina i Odontologia, Departament d'Estomatologia, Clínica Odontològica (PTD II), C/ Gascó Oliag, 1, 46010 Valencia, Spain, sophie.roman@ymail.com.
authors.forename: Sophie
authors.initials: S
authors.lastname: Román-Richon
authors.forename: Vicente
authors.initials: V
authors.lastname: Faus-Matoses
authors.forename: Teresa
authors.initials: T
authors.lastname: Alegre-Domingo
authors.forename: Vicente-José
authors.initials: VJ
authors.lastname: Faus-Llácer
mesh_terms: D002983:Clinical Competence; D004708:Endodontics / Q000193:education*; D006801:Humans; D066298:In Vitro Techniques; D011859:Radiography; D012390:Root Canal Therapy / Q000592:standards*; D012575:Schools, Dental; D013030:Spain; D013335:Students, Dental; D014070:Tooth / Q000000981:diagnostic imaging*