Homan Zandi1, Nikola Petronijevic2, Ibrahimu Mdala3, Anne K Kristoffersen4, Morten Enersen4, Isabela N Rôças5, José F Siqueira5, Dag Ørstavik2. 1. Department of Endodontics, Institute of Clinical Dentistry, University of Oslo, Oslo, Norway; Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway. Electronic address: homanz@odont.uio.no. 2. Department of Endodontics, Institute of Clinical Dentistry, University of Oslo, Oslo, Norway. 3. Department of General Practice, University of Oslo, Oslo, Norway. 4. Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway. 5. Department of Endodontics, Estácio de Sá University, Rio de Janeiro, Brazil.
Abstract
INTRODUCTION: This study compared the clinical and radiographic outcome of endodontic retreatment of teeth with apical periodontitis using either 1% sodium hypochlorite (NaOCl) or 2% chlorhexidine digluconate (CHX) as the irrigant. The influence of residual infection detected by a molecular method on the outcome was also examined. METHODS:Fifty-two root-filled teeth with apical periodontitis were randomly assigned into 2 groups according to the irrigant used during retreatment. Root canal microbiological samples taken before (S1) and after (S2) preparation using either NaOCl or CHX irrigation and after calcium hydroxide medication (S3) were subjected to 16S ribosomal RNA gene-based real-time quantitative polymerase chain reaction (qPCR) to quantify total bacteria. The periapical status was scored using the periapical index and dichotomized as healed (<3) or not healed (≥3) at the 1- and 4-year follow-up. RESULTS:Forty-five (NaOCl, n = 20; CHX, n = 25) and 33 teeth (NaOCl, n = 16; CHX, n = 17) were available at the 1- and 4-year follow-up, respectively. After 1 year, 65% in the NaOCl group and 64% in the CHX group healed, with no differences between them (P > .05). At the later follow-up, the corresponding figures were 81% and 82%, respectively (P > .05). Canals that yielded qPCR-negative results in S3 had a higher healing rate (79%) than qPCR-positive canals (45%, P < .05). The mean bacterial load increased from S2 to S3 in half of the unhealed cases (P < .05). All S3-positive canals containing <3.12 × 103 bacterial cell counts healed. Increasing the apical level of the root canal filling influenced the outcome (P < .05). CONCLUSIONS: No significant differences in the clinical outcome between 1% NaOCl and 2% CHX were found. Bacterial persistence at the time of filling as detected by qPCR significantly affected the outcome.
RCT Entities:
INTRODUCTION: This study compared the clinical and radiographic outcome of endodontic retreatment of teeth with apical periodontitis using either 1% sodium hypochlorite (NaOCl) or 2% chlorhexidine digluconate (CHX) as the irrigant. The influence of residual infection detected by a molecular method on the outcome was also examined. METHODS: Fifty-two root-filled teeth with apical periodontitis were randomly assigned into 2 groups according to the irrigant used during retreatment. Root canal microbiological samples taken before (S1) and after (S2) preparation using either NaOCl or CHX irrigation and after calcium hydroxide medication (S3) were subjected to 16S ribosomal RNA gene-based real-time quantitative polymerase chain reaction (qPCR) to quantify total bacteria. The periapical status was scored using the periapical index and dichotomized as healed (<3) or not healed (≥3) at the 1- and 4-year follow-up. RESULTS: Forty-five (NaOCl, n = 20; CHX, n = 25) and 33 teeth (NaOCl, n = 16; CHX, n = 17) were available at the 1- and 4-year follow-up, respectively. After 1 year, 65% in the NaOCl group and 64% in the CHX group healed, with no differences between them (P > .05). At the later follow-up, the corresponding figures were 81% and 82%, respectively (P > .05). Canals that yielded qPCR-negative results in S3 had a higher healing rate (79%) than qPCR-positive canals (45%, P < .05). The mean bacterial load increased from S2 to S3 in half of the unhealed cases (P < .05). All S3-positive canals containing <3.12 × 103 bacterial cell counts healed. Increasing the apical level of the root canal filling influenced the outcome (P < .05). CONCLUSIONS: No significant differences in the clinical outcome between 1% NaOCl and 2% CHX were found. Bacterial persistence at the time of filling as detected by qPCR significantly affected the outcome.
Authors: Frederico C Martinho; Bruna J M Corazza; Rayana D Khoury; Esteban I F Orozco; Cassia C Toia; Felipe P Machado; Marcia C Valera Journal: Clin Oral Investig Date: 2022-06-20 Impact factor: 3.573