RESUMEN
BACKGROUND AND OBJECTIVES: Tetracycline hydrochloride has been shown to produce changes on periodontally involved root surfaces that can potentially enhance periodontal regeneration. This in vitro study was carried out to compare the root surface changes after scaling and root planing alone, and scaling and root planing followed by application of 100 mg/ml tetracycline hydrochloride under the Scanning Electron Microscope. MATERIALS AND METHOD: Fifteen periodontally compromised freshly extracted single-rooted teeth were thoroughly cleaned. The teeth were then sectioned into thirty blocks and divided into two groups. Group I (control) consisted of teeth which received scaling and and root planing alone and Group II received scaling and root planing followed by application of 100 mg/ml tetracycline hydrochloride under the Scanning Electron Microscope. RESULTS: Tetracycline hydrochloride solution showed statistically highly significant removal of smear layer at 100 mg/ml solution (p < 0.001) and enlargement of dentinal tubule diameter (1.46 microm). CONCLUSION: It can be concluded that tetracycline hydrochloride at concentration 100 mg/ml effectively removes the smear layer and enlarges the dentinal tubules.