title: Time-dependent effects of chitosan on dentin structures.
abstract: Complete debridement with smear layer removal are essential measures for achieving a successful outcome of root canal treatment. The aim of this study was to evaluate the effects of chitosan at different concentrations on the removal of the smear layer and on dentin structure after 3 and 5 min of application. Twelve recently extracted maxillary canine teeth were instrumented using the crown-down technique and irrigated with 1% sodium hypochlorite. The specimens were distributed according to the time and concentration of the final irrigating solution: G1: 0.1% chitosan for 3 min; G2: 0.2% chitosan for 3 min; G3: 0.37% chitosan for 3 min; G4: 0.1% chitosan for 5 min; G5: 0.2% chitosan for 5 min; G6: 0.37% chitosan for 5 min. All samples were prepared for SEM analysis. G1 exhibited removal of the smear layer, but not the smear plugs. G2 showed visible and open tubules with slight erosion of the peritubular dentin. Cleaning in G3 was similar to that in G2, however, the erosive effect was greater. There was expansion of the diameter of the tubules in G4; and in G5 and G6, there was severe erosion with deterioration of dentin surface. In conclusion, 0.2% chitosan for 3 min appeared to be efficient for removing the smear layer, causing little erosion of dentin.
authors.affiliation: Department of Restorative Dentistry, Ribeirão Preto Dental School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Polliana Vilaça
authors.initials: PV
authors.lastname: Silva
authors.forename: Débora Fernandes Costa
authors.initials: DF
authors.lastname: Guedes
authors.forename: Jesus Djalma
authors.initials: JD
authors.lastname: Pécora
authors.forename: Antonio Miranda
authors.initials: AM
authors.lastname: da Cruz-Filho
mesh_terms: D002614:Chelating Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D048271:Chitosan / Q000008:administration & dosage / Q000627:therapeutic use*; D003481:Cuspid / Q000187:drug effects / Q000648:ultrastructure; D003804:Dentin / Q000187:drug effects* / Q000648:ultrastructure; D006801:Humans; D008855:Microscopy, Electron, Scanning; D012388:Root Canal Irrigants / Q000008:administration & dosage / Q000627:therapeutic use*; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods; D016369:Smear Layer; D012973:Sodium Hypochlorite / Q000008:administration & dosage / Q000627:therapeutic use; D007507:Therapeutic Irrigation / Q000379:methods; D013997:Time Factors
chemical_list: D002614:Chelating Agents; D012388:Root Canal Irrigants; D048271:Chitosan; D012973:Sodium Hypochlorite