Infection Control in Teeth with Apical Periodontitis Using a Triple Antibiotic Solution or Calcium Hydroxide with Chlorhexidine: A Randomized Clinical Trial

Abstract

Introduction: This randomized clinical study compared the antibacterial effectiveness of treatment protocols using either a triple antibiotic solution (1 mg/mL) or calcium hydroxide/chlorhexidine paste as interappointment medication in infected canals of teeth with primary apical periodontitis. Methods: The root canals of single-rooted teeth with apical periodontitis were prepared by using a reciprocating single-instrument technique with 2.5% sodium hypochlorite irrigation and then medicated for 1 week with either a triple antibiotic solution (minocycline, metronidazole, and ciprofloxacin) at 1 mg/mL (n = 24) or a calcium hydroxide paste in 2% chlorhexidine gluconate (n = 23). Samples were taken from the canal at the baseline (S1), after chemomechanical preparation (S2), and after intracanal medication (S3). DNA extracts from clinical samples were evaluated for total bacterial reduction using a 16S ribosomal RNA gene-based quantitative polymerase chain reaction assay. Results: All S1 samples were positive for the presence of bacteria, and counts were substantially reduced after treatment procedures (P.05). S2 to S3 reduction was 97% in the antibiotic group and 39% in the calcium hydroxide/chlorhexidine group; only the former reached statistical significance (P