Effectiveness of 1-Visit and Retreatment of Teeth with Persistent/Secondary Endodontic Infection: A Randomized Clinical Trial with 18 Months of Follow-up

Introduction: This randomized clinical trial aimed to compare the effectiveness of endodontic retreatment of teeth with posttreatment apical periodontitis (PTAP) performed in 1 visit versus 2 visits on the reduction of cultivable bacteria (colony-forming units [CFUs]), lipopolysaccharides (LPSs), lipoteichoic acid (LTA), and the periapical lesion volume (mm3) after 18 months of follow-up. Methods: Forty patients diagnosed with PTAP were selected and randomly divided into the following 2 groups: 1-visit retreatment and 2-visit retreatment with the placement of calcium hydroxide medication for 14 days. Cone-beam computed tomographic scans were performed at 2 stages: preoperatively and after 18 months of followup. Samples were collected before and after root canal procedures. A chromogenic limulus amebocyte lysate assay test was used to quantify endotoxins (EU/mL). LTA levels were measured using the enzyme-linked immunosorbent assay (pg/mL). Culture techniques were used to determine cultivable bacteria by counting the CFU (CFU/mL). The volume of the periapical lesions at the onset of the trial and at the 18-month posttreatment follow-up was obtained by the ITK-SNAP program (Cognitica, Philadelphia, PA). Results: All samples showed baseline values greater than those collected after the retreatment protocol for all investigated parameters. A higher bacterial load and lower LTA level were found in the 2-visit group after the retreatment protocol (P , .05), with no statistical differences between the groups regarding endotoxin levels and periapical lesion volume (mm3) at the 18-month follow-up analyzed by cone-beam computed tomographic imaging (P . .05). Conclusions: Endodontic retreatment in 1 or 2 visits exhibited equally favorable periapical healing at 18 months, with no statistically significant differences between groups. (J Endod 2022;48:4-14.)

Automated summary

The study compared the effectiveness of endodontic retreatment in 1 visit versus 2 visits on the reduction of bacteria and other parameters in teeth with posttreatment apical periodontitis over an 18-month period. Results showed differences in bacterial load and LTA levels between the two groups, but no significant differences in endotoxin levels and periapical lesion volume. Both treatment methods exhibited equally favorable periapical healing at 18 months.