title: Early antimicrobial activity of intracanal medications on the external root surface of periodontally compromised teeth.
abstract: OBJECTIVE
  To verify the effect of scaling and root planing on the antimicrobial activity of intracanal medications on the external root surface of periodontally compromised teeth.
  
  
  METHODS
  Forty single-rooted extracted teeth were randomly assigned for visible calculus removal or scaling and root planing. Samples were separated into four groups-chlorhexidine, tetracycline hydrochloride, calcium hydroxide, or saline solution-and immersed in semisolid media and seeded with Micrococcus luteus for 24 hours. The zones of inhibition were measured using a profile projector.
  
  
  RESULTS
  Calcium hydroxide and saline solution did not show bacterial growth inhibition. Chlorhexidine and tetracycline showed the occurrence of zones of inhibition in 70% and 40% of specimens, respectively.
  
  
  CONCLUSIONS
  Partial antimicrobial activity on the external root surface was found when chlorhexidine and tetracycline solutions were used as intracanal medications; however, root planing procedures may modify this condition.
authors.affiliation: Division of Periodontics, Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, Brazil.
authors.forename: Mônica Reggi Reis
authors.initials: MR
authors.lastname: Silva
authors.forename: Leandro
authors.initials: L
authors.lastname: Chambrone
authors.forename: Antônio Carlos
authors.initials: AC
authors.lastname: Bombana
authors.forename: Luiz A
authors.initials: LA
authors.lastname: Lima
mesh_terms: D000891:Anti-Infective Agents, Local / Q000008:administration & dosage*; D002126:Calcium Hydroxide / Q000008:administration & dosage; D002710:Chlorhexidine / Q000008:administration & dosage; D055113:Chronic Periodontitis / Q000628:therapy*; D015169:Colony Count, Microbial; D003692:Delayed-Action Preparations; D003728:Dental Calculus / Q000628:therapy; D004058:Diffusion; D052978:Disk Diffusion Antimicrobial Tests; D016982:Micrococcus luteus / Q000187:drug effects* / Q000254:growth & development; D012388:Root Canal Irrigants / Q000008:administration & dosage*; D016745:Root Planing; D013499:Surface Properties; D013752:Tetracycline / Q000008:administration & dosage; D014092:Tooth Root / Q000382:microbiology*
chemical_list: D000891:Anti-Infective Agents, Local; D003692:Delayed-Action Preparations; D012388:Root Canal Irrigants; D013752:Tetracycline; D002126:Calcium Hydroxide; D002710:Chlorhexidine