title: Apical enlargement: influence on overextensions during in vitro vertical compaction.
abstract: This study evaluated the apical movement of gutta-percha master cones under in vitro vertical compaction. A split natural tooth model was used. The gutta-percha cones were first fitted at 0.5 and 1.0 mm short of the apical end of a canal instrumented up to a size 25 file and then condensed. Then the canal was cleaned of gutta-percha and reshaped up to a size 40 file, other cones fitted and obturated. Photographs were taken before and after compaction and measurements were made. The canals instrumented to a size 40 file had significantly more overextensions than those instrumented to a size 25 file.
authors.affiliation: Department of Research, Lebanese University (section II), Beirut, Lebanon.
authors.forename: G M
authors.initials: GM
authors.lastname: Yared
authors.forename: F E
authors.initials: FE
authors.lastname: Bou Dagher
mesh_terms: D000704:Analysis of Variance; D006171:Gutta-Percha; D006801:Humans; D012389:Root Canal Obturation / Q000009:adverse effects / Q000379:methods; D012390:Root Canal Therapy / Q000295:instrumentation*
chemical_list: D006171:Gutta-Percha