Aim: The purpose of the present study is to evaluate the healing of periapical lesions of teeth with positive and negative canal cultures at the time of obturation, and to evaluate the periapical healing of teeth treated in one visit (without) or in two visits with an interappointment dressing of calcium hydroxide.
Methodology: Thirty-nine patients received root-canal treatment. In the first visit, teeth were instrumented, and 18 of these teeth were filled (after microbiological sampling) with calcium hydroxide in sterile saline. The other 21 teeth were obturated with gutta-percha and AH-26 sealer after microbiological sampling. Four weeks later, the teeth with calcium hydroxide were accessed again and after microbiological sampling they were obturated with gutta-percha and AH-26 sealer. Healing of periapical radiolucency was recorded over a period up to 4.5 years.
Results: In both the treatment groups, the size of the periapical lesions reduced significantly during the follow-up period. Complete radiographic healing was observed in 81% of the cases in the one-visit group, and in 71% of the cases in the two-visit group. The probability of success increased continuously over time for both treatment groups. Seven out of eight cases (87.5%) that showed a positive root-canal culture at the time of obturation healed. The number of colony forming units (CFU) in six out of eight positive canals was <10(2) CFU mL(-1).
Conclusions: Within the limitations of this study, no significant differences in healing of periapical radiolucency was observed between teeth that were treated in one visit (without) and two visits with inclusion of calcium hydroxide for 4 weeks. The presence of a positive bacterial culture (CFU<10(2)) at the time of filling did not influence the outcome of treatment.