title: Influence of apical foramen widening and sealer on the healing of chronic periapical lesions induced in dogs' teeth.
abstract: OBJECTIVE
  The aim of this study was to evaluate the influence of apical foramen widening on the healing of chronic periapical lesions in dogs' teeth after root canal filling with Sealer 26 or Endomethasone.
  
  
  METHODS
  Forty root canals of dogs' teeth were used. After pulp extirpation, the canals were exposed to the oral cavity for 180 days for induction of periapical lesions, and then instrumented up to a size 55 K-file at the apical cemental barrier. In 20 roots, the cemental canal was penetrated and widened up to a size 25 K-file; in the other 20 roots, the cemental canal was preserved (no apical foramen widening). All canals received a calcium hydroxide intracanal dressing for 21 days and were filled with gutta-percha and 1 of the 2 sealers: group 1: Sealer 26/apical foramen widening; group 2: Sealer 26/no apical foramen widening; group 3: Endomethasone/apical foramen widening; group 4: Endomethasone/no apical foramen widening. The animals were killed after 180 days, and serial histologic sections from the roots were prepared for histomorphologic analysis. Scores were assigned according to preestablished histomorphologic parameters and analyzed statistically by Kruskal-Wallis and Mann-Whitney U tests.
  
  
  RESULTS
  Regarding new cementum formation, repair of cementum and bone resorption areas, presence of microorganisms, inflammatory cell infiltrate and periodontal ligament conditions, significantly better periapical healing was obtained when foramen widening was done and Sealer 26 was used.
  
  
  CONCLUSIONS
  Apical foramen widening and calcium hydroxide-containing sealer were more favorable to the healing of chronic periapical lesions.
authors.affiliation: Dental School, University of Marília, Marília, Brazil.
authors.forename: Suelen Cristine
authors.initials: SC
authors.lastname: Borlina
authors.forename: Valdir
authors.initials: V
authors.lastname: de Souza
authors.forename: Roberto
authors.initials: R
authors.lastname: Holland
authors.forename: Sueli Satomi
authors.initials: SS
authors.lastname: Murata
authors.forename: João Eduardo
authors.initials: JE
authors.lastname: Gomes-Filho
authors.forename: Eloi
authors.initials: E
authors.lastname: Dezan Junior
authors.forename: Jeferson José de Carvalho
authors.initials: JJ
authors.lastname: Marion
authors.forename: Domingos Dos Anjos
authors.initials: Ddos A
authors.lastname: Neto
mesh_terms: D000818:Animals; D001729:Bismuth / Q000627:therapeutic use; D001862:Bone Resorption / Q000188:drug therapy; D002126:Calcium Hydroxide / Q000627:therapeutic use*; D003739:Dental Cementum / Q000187:drug effects; D003907:Dexamethasone / Q000627:therapeutic use; D004195:Disease Models, Animal; D004285:Dogs; D004338:Drug Combinations; D005557:Formaldehyde / Q000627:therapeutic use; D006854:Hydrocortisone / Q000627:therapeutic use; D010483:Periapical Diseases / Q000628:therapy*; D010513:Periodontal Ligament / Q000187:drug effects; D012387:Root Canal Filling Materials / Q000627:therapeutic use*; D012388:Root Canal Irrigants / Q000627:therapeutic use*; D018915:Root Canal Preparation / Q000379:methods*; D018709:Statistics, Nonparametric; D013943:Thymol / Q000031:analogs & derivatives / Q000627:therapeutic use; D019227:Tooth Apex / Q000601:surgery*
chemical_list: D004338:Drug Combinations; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; C080620:Sealer 26; C011244:corticosteroid methanetriol mixture; D005557:Formaldehyde; D013943:Thymol; D003907:Dexamethasone; D002126:Calcium Hydroxide; D001729:Bismuth; D006854:Hydrocortisone