title: Quality of cold and warm gutta-percha fillings in oval canals in mandibular premolars.
abstract: OBJECTIVE
  The aim of this study was to determine the quality of cold and warm gutta-percha fillings in oval canals.
  
  
  METHODS
  Two groups of mandibular premolars with oval canals were selected after bucco-lingual and mesio-distal radiographs indicated an internal long: short diameter of > or =1.6 at a level 5 mm from the apex. After instrumentation they were obturated, respectively, by cold lateral compaction of gutta-percha cones (cold GP) and vertical compaction of warm gutta-percha (warm GP). Leakage along apical root fillings was measured using a fluid transport model. After the leakage test, horizontal sections were cut 2 and 4 mm from the apex. The area of the canal and gutta-percha in cross-sections was measured using an image analysis program. The quality of root fillings was evaluated by calculating the percentage of gutta-percha-filled canal area (PGP).
  
  
  RESULTS
  No significant difference in leakage was found between the two groups (P = 0.570). The warm GP group produced significantly higher PGPs than the cold GP group 4 mm from the apex only (P = 0.522 at 2 mm: P = 0.000 at 4 mm).
  
  
  CONCLUSIONS
  The percentage of gutta-percha-filled canal area using warm GP was greater than that of the cold GP in oval canals.
authors.affiliation: Department of Cariology Endodontology Pedodontology, Academic Centre for Dentistry Amsterdam (ACTA), The Netherlands. M.Wu@acta.nl
authors.forename: M K
authors.initials: MK
authors.lastname: Wu
authors.forename: A
authors.initials: A
authors.lastname: Kast'áková
authors.forename: P R
authors.initials: PR
authors.lastname: Wesselink
mesh_terms: D001641:Bicuspid / Q000033:anatomy & histology; D003080:Cold Temperature; D003763:Dental Leakage / Q000517:prevention & control; D003786:Dental Pulp Cavity / Q000033:anatomy & histology*; D006171:Gutta-Percha; D006358:Hot Temperature; D006801:Humans; D008334:Mandible; D011787:Quality of Health Care; D012389:Root Canal Obturation / Q000379:methods*; D014092:Tooth Root / Q000033:anatomy & histology
chemical_list: D006171:Gutta-Percha