title: Effects of Clinical Training and Case Difficulty on the Radiographic Quality of Root Canal Fillings Performed by Dental Students in Saudi Arabia.
abstract: BACKGROUND
  The aim of this study was to evaluate the effects of training duration and case difficulty on the radiographic quality of root canal fillings performed by dental students in Saudi Arabia.
  
  
  METHODS
  A longitudinal cohort study was conducted at King Saud University. Root canal treatments performed by 55 dental students from 2012-2014 were included in the study. Each student treated at least five teeth during the first year of clinical endodontic training and another five teeth during the second year. Case difficulty was assessed based on tooth position in the dental arch and preoperative conditions. The radiographic quality of the root canal filling was evaluated by two endodontists blinded to treatment completion date. The evaluation criteria were adequate obturation, presence of mishaps and preparation taper. The data were statistically analysed using univariate and multivariate logistic regression analyses; and the level of significance was set at 0.05.
  
  
  RESULTS
  Inadequate obturation and mishaps were significantly less prevalent in teeth treated after 2 years of clinical training. The odds ratios for inadequate obturation and mishaps increased significantly as tooth position moved posteriorly. Inadequate obturation and more mishaps were significantly more prevalent in teeth with preoperative conditions. Preparation taper was not significantly affected by training duration or case difficulty.
  
  
  CONCLUSIONS
  The quality of root canal fillings performed by Saudi students was adversely affected by case difficulty. The radiographic quality of root canal fillings improved significantly after 2 years of clinical training. Preparation taper outcome is likely dependent on the preparation technique and instrument taper.
authors.affiliation: Department of Restorative Dental Science, King Saud University, Riyadh, Saudi Arabia;
authors.forename: Reem Siraj
authors.initials: RS
authors.lastname: Alsulaimani
authors.affiliation: Department of Restorative Dental Science, King Saud University, Riyadh, Saudi Arabia;
authors.forename: Kholod Khalil
authors.initials: KK
authors.lastname: Al-Manei
authors.affiliation: Department of Restorative Dental Science, King Saud University, Riyadh, Saudi Arabia;
authors.forename: Sara
authors.initials: S
authors.lastname: A Alsubait
authors.affiliation: Department of Periodontics and Community Dentistry, King Saud University, Riyadh, Saudi Arabia;
authors.forename: Razan Shafik
authors.initials: RS
authors.lastname: AlAqeely
authors.affiliation: Department of Prosthetic Dental Science, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Sharifa
authors.initials: S
authors.lastname: A M Al-Shehri
authors.affiliation: Department of Restorative Dental Science, King Saud University, Riyadh, Saudi Arabia;
authors.forename: Ebtissam
authors.initials: E
authors.lastname: M Al-Madi
keywords: Obturation Density; Obturation Length; Preparation Taper; Procedural Accident; Root Canal Treatment