title: Smear layer removal and collagen fiber exposure using tetracycline hydrochloride conditioning.
abstract: OBJECTIVE
  Smear layer removal and collagen fiber exposure may improve periodontal treatment and regeneration. This in vitro study assessed smear layer removal and collagen fiber exposure after tetracycline hydrochloride (TTC) application on root surfaces using scanning electron microscopy (SEM).
  
  
  METHODS
  Root cementum was removed with diamond burs followed by scaling and root planning. Four hundred fifty samples were divided into ten groups: a control (saline application) and nine different TTC concentrations were applied at doses of 10, 25, 50, 75, 100, 125, 150, 200, and 250 mg/ml. The TTC application was performed in all groups in three different ways (passive, brushing, and burnishing) and at three different periods of conditioning (1, 2, and 3 minutes). A previously trained, calibrated, and blind examiner evaluated photomicrographs of the samples using Sampaio's index (2005). Statistical analysis was performed using the Kruskal-Wallis' and Dunn's tests.
  
  
  RESULTS
  The concentrations of 50 mg/mL and 75 mg/mL applied by burnishing were the most effective in smear layer removal and collagen fiber exposure. Both the passive mode of application (p=0.0001) and 1 minute period of application (p=0.002) were the least effective.
  
  
  CONCLUSIONS
  The concentrations of 50 mg/mL and 75 mg/mL applied by burnishing during 2 or 3 minutes were the most effective.
  
  
  CONCLUSIONS
  These parameters may be applied in periodontal procedures involving TTC root conditioning to optimize results.
authors.affiliation: Department of Diagnostic and Surgery, School of Dentistry at Araraquara, Sãu Paulo State University, UNESP, São Paulo, Brazil. duishi@gmail.com
authors.forename: Eduardo de Paula
authors.initials: EP
authors.lastname: Ishi
authors.forename: Andrea Abi Rached
authors.initials: AA
authors.lastname: Dantas
authors.forename: Luiz Henrique Carvalho
authors.initials: LH
authors.lastname: Batista
authors.forename: Mirian Aparecida
authors.initials: MA
authors.lastname: Onofre
authors.forename: Jose Eduardo Cezar
authors.initials: JE
authors.lastname: Sampaio
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D003648:Decalcification Technique / Q000379:methods; D003739:Dental Cementum / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D024022:Fibrillar Collagens / Q000648:ultrastructure*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D016745:Root Planing; D016369:Smear Layer; D013752:Tetracycline / Q000008:administration & dosage*
chemical_list: D000900:Anti-Bacterial Agents; D024022:Fibrillar Collagens; D013752:Tetracycline