title: A comparison of D-, E-, and F-speed conventional intraoral radiographic films in endodontic measurement.
abstract: OBJECTIVE
  We sought to compare observer measurement error and subjective ratings for International Standards Organization D-, E-, and F-speed direct exposure dental x-ray films used to determine endodontic working lengths.
  
  
  METHODS
  Radiographs were exposed to achieve a standard background density of approximately 2.0. Three human maxillary posterior teeth for which No. 10 K-files had been placed at various lengths within 4 canals were studied in a cadaver section. A total of 30 radiographs were used (10 from each film type). Five licensed dentists excluding all authors viewed the radiographs independently and in random sequence. Distances from the file tips to the radiographic apices were measured and were compared with known lengths for error determination. The observing dentists also subjectively rated the images as desirable or undesirable. Statistical methods included a 3-factor ANOVA with Tukey honestly significant difference post hoc analysis to compare objective measurements and chi-square with respect to subjective ratings.
  
  
  RESULTS
  No significant differences were attributable to film speed grouping or observers (P > .05); however, there was a specimen effect in that a significant difference was found in measurement accuracy among the 4 canals (P < .05). Differences in subjective ratings for the 3 film types were not statistically significant (P > .05).
  
  
  CONCLUSIONS
  All 3 film types were similar in objective and subjective ratings. This being the case, the faster film is preferred to minimize the radiation dose to the patient.
authors.affiliation: School of Dentistry, The University of Louisville, Kentucky 40292, USA.
authors.forename: J Chris
authors.initials: JC
authors.lastname: Sheaffer
authors.forename: Paul D
authors.initials: PD
authors.lastname: Eleazer
authors.forename: James P
authors.initials: JP
authors.lastname: Scheetz
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Clark
authors.forename: Allan G
authors.initials: AG
authors.lastname: Farman
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D003786:Dental Pulp Cavity / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D006801:Humans; D009811:Odontometry; D011861:Radiography, Dental / Q000379:methods*; D018709:Statistics, Nonparametric; D014962:X-Ray Film