title: Periapical tissue response after use of intermediate restorative material, gutta-percha, reinforced zinc oxide cement, and mineral trioxide aggregate as retrograde root-end filling materials: a histologic study in dogs.
abstract: OBJECTIVE
  To investigate the periapical tissue response of 4 different retrograde root-filling materials, ie, intermediate restorative material, thermoplasticized gutta-percha, reinforced zinc oxide cement (Super-EBA), and mineral trioxide aggregate (MTA), in conjunction with an ultrasonic root-end preparation technique in an animal model.
  
  
  METHODS
  Vital roots of the third and fourth right mandibular premolars in 6 healthy mongrel dogs were apicectomized and sealed with 1 of the materials using a standardized surgical procedure. After 120 days, the animals were sacrificed and the specimens were analyzed radiologically, histologically, and scanning electron microscopically. The Fisher exact test was performed on the 2 outcome values.
  
  
  RESULTS
  Twenty-three sections were analyzed histologically. Evaluation showed better re-establishment of the periapical tissues and generally lower inflammatory infiltration in the sections from teeth treated with the intermediate restorative material and the MTA. New root cement on the resected dentin surfaces was seen on all sections regardless of the used material. New hard tissue formation, directly on the surface of the material, was seen only in the MTA sections. There was no statistical difference in outcome among the tested materials.
  
  
  CONCLUSIONS
  The results from this dog model favor the intermediate restorative material and MTA as retrograde fillings when evaluating the bone defect regeneration. MTA has the most favorable periapical tissue response when comparing the biocompatibility of the materials tested.
authors.affiliation: Maxillofacial Unit, Halmstad Hospital, Halland, Sweden. dan-ake.valivaara@regionhalland.se
authors.forename: Dan-Åke
authors.initials: DÅ
authors.lastname: Wälivaara
authors.forename: Peter
authors.initials: P
authors.lastname: Abrahamsson
authors.forename: Sten
authors.initials: S
authors.lastname: Isaksson
authors.forename: Luiz Antonio
authors.initials: LA
authors.lastname: Salata
authors.forename: Lars
authors.initials: L
authors.lastname: Sennerby
authors.forename: Christer
authors.initials: C
authors.lastname: Dahlin
mesh_terms: D017607:Aluminum Compounds / Q000627:therapeutic use*; D000539:Alveolar Process / Q000473:pathology; D000818:Animals; D001047:Apicoectomy / Q000379:methods; D001641:Bicuspid / Q000601:surgery; D001672:Biocompatible Materials / Q000627:therapeutic use; D017610:Calcium Compounds / Q000627:therapeutic use*; D003739:Dental Cementum / Q000473:pathology; D003804:Dentin / Q000473:pathology; D017220:Dentin-Bonding Agents / Q000627:therapeutic use*; D004285:Dogs; D004338:Drug Combinations; D006171:Gutta-Percha / Q000627:therapeutic use*; D008334:Mandible / Q000601:surgery; D008768:Methylmethacrylates / Q000627:therapeutic use*; D008855:Microscopy, Electron, Scanning; D023421:Models, Animal; D010027:Osteotomy / Q000379:methods; D010087:Oxides / Q000627:therapeutic use*; D010485:Periapical Periodontitis / Q000473:pathology; D010486:Periapical Tissue / Q000187:drug effects* / Q000473:pathology; D012184:Retrograde Obturation / Q000379:methods*; D012387:Root Canal Filling Materials / Q000627:therapeutic use*; D018915:Root Canal Preparation / Q000379:methods; D017640:Silicates / Q000627:therapeutic use*; D013997:Time Factors; D059708:Ultrasonic Surgical Procedures / Q000379:methods; D015034:Zinc Oxide / Q000627:therapeutic use*; D015035:Zinc Oxide-Eugenol Cement / Q000627:therapeutic use*
chemical_list: D017607:Aluminum Compounds; D001672:Biocompatible Materials; D017610:Calcium Compounds; D017220:Dentin-Bonding Agents; D004338:Drug Combinations; D008768:Methylmethacrylates; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; D015035:Zinc Oxide-Eugenol Cement; C086631:mineral trioxide aggregate; C031667:IRM cement; C084074:Super EBA; D006171:Gutta-Percha; D015034:Zinc Oxide