Early antimicrobial activity of intracanal medications on the external root surface of periodontally compromised teeth.

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.

Method And Materials: 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.

Conclusion: 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.