TY - JOUR
T1 - A Comparison between In Vivo Radiographic Working Length Determination and Measurement after Extraction
AU - Williams, Clayton B.
AU - Joyce, Anthony P.
AU - Roberts, Steven
PY - 2006/7
Y1 - 2006/7
N2 - The purpose of this study was to compare the difference between the in vivo working length established by viewing a periapical radiograph and the in vitro measurement from the file tip to the apical foramen of the extracted tooth. Twenty-six canals from teeth that had been treatment planned for extraction were accessed under rubber dam isolation. The coronal portion of each canal was flared using Gates Glidden drills, and a K-type file was inserted down the canal until an electronic apex locator indicated that the file had reached the apex. A size 20 K-type file was locked into place with glass ionomer cement at this position. A radiograph was exposed and the tooth was extracted. Each tooth was viewed using a videomicroscope at 30× original magnification, and the distance from the file tip to the most coronal aspect of the major foramen was measured. Six examiners viewed each radiograph and assessed the working length of each canal. χ2 analysis of the data revealed a significant difference (p < 0.01) between the estimation of working lengths and the microscopic measurements. The examiners overestimated the distance between the file tip and the apical foramen of the tooth when the file was placed short, and underestimated the distance when the file was placed long. In conclusion, when the file is short it is actually closer to the apical foramen than it appears radiographically; when it is long it is actually longer than it appears radiographically.
AB - The purpose of this study was to compare the difference between the in vivo working length established by viewing a periapical radiograph and the in vitro measurement from the file tip to the apical foramen of the extracted tooth. Twenty-six canals from teeth that had been treatment planned for extraction were accessed under rubber dam isolation. The coronal portion of each canal was flared using Gates Glidden drills, and a K-type file was inserted down the canal until an electronic apex locator indicated that the file had reached the apex. A size 20 K-type file was locked into place with glass ionomer cement at this position. A radiograph was exposed and the tooth was extracted. Each tooth was viewed using a videomicroscope at 30× original magnification, and the distance from the file tip to the most coronal aspect of the major foramen was measured. Six examiners viewed each radiograph and assessed the working length of each canal. χ2 analysis of the data revealed a significant difference (p < 0.01) between the estimation of working lengths and the microscopic measurements. The examiners overestimated the distance between the file tip and the apical foramen of the tooth when the file was placed short, and underestimated the distance when the file was placed long. In conclusion, when the file is short it is actually closer to the apical foramen than it appears radiographically; when it is long it is actually longer than it appears radiographically.
KW - Electronic apex locator
KW - major foramen
KW - minor diameter
KW - radiographic working length
KW - working length
KW - working length determination
UR - http://www.scopus.com/inward/record.url?scp=33745204176&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33745204176&partnerID=8YFLogxK
U2 - 10.1016/j.joen.2005.10.044
DO - 10.1016/j.joen.2005.10.044
M3 - Article
C2 - 16793467
AN - SCOPUS:33745204176
SN - 0099-2399
VL - 32
SP - 624
EP - 627
JO - Journal of endodontics
JF - Journal of endodontics
IS - 7
ER -