title: The use of high-resolution digital imaging technology for small diameter K-file length determination in endodontics.
abstract: To assess the reliability of high resolution intra-oral photostimulable storage phosphor (PSP) and complementary metal-oxide semiconductor (CMOS) imaging systems for working length (WL) assessment of small K-files in narrow and curved root canals. Eleven narrow and curved canals from extracted molars were used as pre-test for sample-size calculation. Nineteen canals from four cadavers were used for endodontic length assessment in the final study. Small K-files (ISO size 6, 8, and 10) were introduced into the canals at prepared length. Digital intra-oral radiographs were obtained using high-resolution Vistascan PSP plates and Sigma M CMOS active pixel sensor with a DC X-ray tube at 70 kV, 7 mA, and 0.16 s. Both image series were assessed with and without use of a dedicated endodontic filter. Three observers measured WLs for comparison to the gold standards of a digital millimeter ruler. Multiple regression analysis of the dependent measurements revealed no significant influence of imaging sensor (PSP or CMOS, p = 0.34) and image processing (p = 0.97). For ISO file size, however, there was a significant difference (p = 0.08) at a level of 10%. Observers mostly underestimated lengths using PSP but overestimated them on CMOS. Almost all radiographic measurements (96-98%) were within 2-mm deviation, while 71% to 82% deviated within 1 mm. Dedicated filtering and sensor type did not influence the outcome of WL determination of small file sizes when using high-resolution imaging sensors. WL determination with ISO file 6 did show a significant difference compared to ISO 8 and 10 but mostly for deviations <1.5 mm.
authors.affiliation: Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Katholieke Universiteit Leuven, Kapucijnenvoer 7, Leuven, Belgium. bart.vandenberghe@med.kuleuven.be
authors.forename: Bart
authors.initials: B
authors.lastname: Vandenberghe
authors.forename: Marius
authors.initials: M
authors.lastname: Bud
authors.forename: Asti
authors.initials: A
authors.lastname: Sutanto
authors.forename: Reinhilde
authors.initials: R
authors.lastname: Jacobs
mesh_terms: D002102:Cadaver; D002138:Calibration; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging*; D004867:Equipment Design; D005374:Filtration / Q000295:instrumentation; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods; D008963:Molar / Q000000981:diagnostic imaging; D015588:Observer Variation; D011856:Radiographic Image Enhancement / Q000295:instrumentation / Q000379:methods; D019252:Radiography, Dental, Digital / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results; D018915:Root Canal Preparation / Q000295:instrumentation*; D016037:Single-Blind Method; D014963:X-Ray Intensifying Screens