Effectiveness of the Proton Pump Inhibitor Omeprazole Associated with Calcium Hydroxide as Intracanal Medication: An In Vivo Study

IntroductionThe objective of this study was to evaluate the efficacy of the association of a proton pump inhibitor (omeprazole) with Ca(OH)2 as intracanal medication in a rat model of periapical lesions.MethodsPeriapical lesions were induced on the first right mandibular molar tooth of 36 male Wistar rats (6 per group). After 28 days, the distal canal of each tooth was prepared, filled with the respective dressing (negative control group, PEG 400; positive control group, Ca(OH)2 + PEG400; test group, Ca(OH)2 + omeprazole + PEG 400), and sealed with amalgam for 15 or 28 days. Microbiological samples were taken in 3 periods: S1, after 28 days of lesion induction; S2, after the biomechanical preparation; and S3, after the medication (15 and 28 days).ResultsThe radiographic and histologic analysis revealed that either Ca(OH)2 or Ca(OH)2 plus omeprazole dressings produced a reduction of periapical lesions at 28 days, when compared with the negative control group. The reduction of periapical lesions and inflammatory cell infiltration was visibly improved by associating omeprazole with Ca(OH)2, with an increase of reparative bone areas. The microbiological assessment showed a significant decrease of colony-forming units count from S1 to S2 or S3 collecting times, but no differences were observed between the S2 and the S3 time-periods or among the experimental groups within the S3 period. Further bacterial characterization showed a possible selective activity of the medications.ConclusionsOur data showed that association of omeprazole with Ca(OH)2 favored a superior repair of rat periapical lesions and seemed to display different selective activity over endodontic microbiota, in comparison with the conventional Ca(OH)2 dressing.