RESUMO
Scanning electron microscopy (SEM) was used to evaluate root surface characteristics of human teeth affected with periodontitis following periodontal instrumentation and topical application of tetracycline HCl (TTC-HCl; pH 1.6; 4 min). Specimens were randomly assigned to periodontal instrumentation alone (control 1); periodontal instrumentation plus TTC-HCl (test 1); periodontal instrumentation plus trypsin solution after extraction (control 2); and periodontal instrumentation plus TTC-HCl plus trypsin solution after extraction (test 2). Tetracycline solution was applied with a cotton pellet. Twenty-two single root periodontitis affected human teeth scheduled for extraction were selected. Mucoperiosteal flaps were raised, root surfaces were mechanically and chemically treated, flaps were repositioned and maintained in place for 20 min. Teeth were extracted, rinsed and placed in cold phosphate buffer solution (PBS) and control 2 and test 2 groups were treated with trypsin solution. Specimens were examined using SEM. Smear layer was successfully removed, exposing dentinal tubules; however, fibrin network formation in situ was not improved by application of TTC-HCl.