title: Histologic Analysis of the Influence of a Gelatin-based Scaffold in the Repair of Immature Dog Teeth Subjected to Regenerative Endodontic Treatment.
abstract: BACKGROUND
  Regenerative endodontic treatment is a new and promising approach to manage immature teeth with necrotic pulps and apical periodontitis. The use of scaffolds is essential to treatment success, but many materials are difficult to acquire and have a high cost. This study assessed tissue repair in immature dog teeth with necrotic pulps and apical periodontitis after using a gelatin-based scaffold (Gelfoam; Pharmacia & Upjohn Co, Kalamazoo, MI).
  
  
  METHODS
  Apical periodontitis was induced in 20 immature dog teeth. After disinfection with triple antibiotic paste for 2 weeks, canals were irrigated, dried, and filled with a blood clot alone (10 teeth) or combined with Gelfoam (10 teeth). Another 10 teeth were used as negative controls (no intervention). After 7 months, the dogs were euthanized. Histologic sections were stained with hematoxylin-eosin and analyzed in relation to tissue repair. Categoric data were analyzed using the Fisher exact test (P < .05), numeric data (histomorphometric analysis), and the Mann-Whitney U test.
  
  
  RESULTS
  Histologic analysis revealed a higher percentage of roots with new cementumlike mineralized tissue and connective tissue inside the canal in the blood clot + Gelfoam group (P < .001). Histomorphometric analysis showed a higher area of mineralized tissue in the same group (P = .029). Apical extension of root and inflammation were similar between the experimental groups. The new tissue formed onto canal walls and in the root canal space showed characteristics of cementum and periodontal ligament, respectively.
  
  
  CONCLUSIONS
  The use of a gelatin-based scaffold (Gelfoam) combined with a blood clot improved repair in immature dog teeth with apical periodontitis subjected to regenerative endodontic treatment.
authors.affiliation: Dental Service, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil. Electronic address: clacirlondero@gmail.com.
authors.forename: Clacir de Lourdes Dotto
authors.initials: Cde L
authors.lastname: Londero
authors.affiliation: Department of Stomatology, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil.
authors.forename: Claudia Medianeira Londero
authors.initials: CM
authors.lastname: Pagliarin
authors.affiliation: Department of Dentistry, Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina, Brazil.
authors.forename: Mara Cristina Santos
authors.initials: MC
authors.lastname: Felippe
authors.affiliation: Department of Dentistry, Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina, Brazil.
authors.forename: Wilson Tadeu
authors.initials: WT
authors.lastname: Felippe
authors.affiliation: Department of Pathology, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil.
authors.forename: Cristiane Cademartori
authors.initials: CC
authors.lastname: Danesi
authors.affiliation: Graduate Program, School of Dentistry, Universidade Luterana do Brasil, Canoas, Rio Grande do Sul, Brazil.
authors.forename: Fernando Branco
authors.initials: FB
authors.lastname: Barletta
mesh_terms: D000818:Animals; D001641:Bicuspid / Q000033:anatomy & histology; D003739:Dental Cementum / Q000378:metabolism; D003790:Dental Pulp Necrosis / Q000628:therapy*; D004285:Dogs; D005781:Gelatin Sponge, Absorbable; D008334:Mandible; D010485:Periapical Periodontitis / Q000628:therapy*; D018915:Root Canal Preparation / Q000379:methods*; D012390:Root Canal Therapy / Q000379:methods*; D054457:Tissue Scaffolds; D014092:Tooth Root / Q000033:anatomy & histology*
keywords: Apexification; revascularization; scaffold; tissue engineering