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Introduction In this study, we examined the effect of mineral trioxide aggregate (MTA) on macrophage polarization and the potential involvement of Axl/nuclear factor kappa B (NF-κB) signaling in mediating the effect of MTA. Methods The human monocyte cell line THP-1 was cultured with MTA solution for 1, 2, or 3 days, and the population change of M2 macrophages was analyzed by flow cytometry. Expression of M2 cytokines was examined by enzyme-linked immunosorbent assay. Phagocytosis and angiogenesis-induction ability were also assayed. The involvement of Axl/NF-κB signaling in MTA-treated cells was examined by analyzing phosphorylation status of Axl, Akt, IKKα/β, and IκBα. Specific inhibitors for Axl/Akt/NF-κB signaling were added to MTA-treated THP-1 cells, and their cytokine expression change was examined. Results Flow cytometry analysis showed that MTA treatment increased CD206＋ cells in a time-dependent way. After MTA treatment, the expression of M2-related cytokines was up-regulated. MTA also enhanced phagocytic ability and the ability of THP-1 cells to induce angiogenesis. Treatment of MTA led to activate Axl/Akt/NF-kB signal axis by phosphorylation of Axl, Akt, IKKα/β, IκBα, and p65. In addition, MTA-induced interleukin 10, transforming growth factor beta, and vascular endothelial growth factor expression was suppressed as specific inhibitors were added. Conclusions Our findings indicate that MTA is able to induce macrophage polarization toward the M2 phenotype, with up-regulation of interleukin 10, transforming growth factor beta, and vascular endothelial growth factor, and that Axl/Akt/NF-κB signaling participates in this process. These results provide the cellular and molecular basis of MTA's anti-inflammatory action in clinical applications.

Background/purpose Condensing osteitis (CO) is a common lesion of the jaw bone. This study surveyed the occurrence of mandible CO and its distribution in the mandible in a Taiwanese population. Materials and methods Panoramic radiographs and clinical information of 1098 patients at the Dental Department of Tri-Service General Hospital (Taipei, Taiwan) were collected. The patient data were analyzed to determine the CO disease status, patient age distribution, sex, CO location in the mandible, and the status of the affected tooth. Results Seventy-five CO lesions were identified in 63 patients. The prevalence of CO in the mandible was 5.7%. Eight (10.7%) CO cases were associated with teeth that had crowns and/or bridges, 16 (21.3%) CO cases were associated with teeth that had caries or restorations; 22 (29.3%) CO cases were associated with teeth that had received root canal therapy, nine (12%) CO cases were associated with teeth with periodontal diseases, and 20 (26.7%) CO cases were located in the tooth extraction area. The percentage of females and males was 65.3% and 34.7%, respectively. Ten (13.3%) CO cases and 65 (86.7%) CO cases were identified in the premolar and molar area, respectively. The most common site of CO was in the first molar region. Conclusion In our study population, the CO lesion occurs more commonly in female patients who were in their 60s. The mandibular 1 st molar and teeth that had received root canal therapy had the highest association with CO. The CO distribution, as determined from this study, can provide valuable information for future clinical references.

Introduction The aim of this study was to assess the root canal configurations in permanent mandibular lateral incisors (PMLIs) and the correlation between the root canal configurations of PMLIs with the appearance of a distolingual root (DLR) in permanent mandibular first molars (PMFMs) using cone-beam computed tomographic (CBCT) imaging. Methods A total of 1200 CBCT images (300 patients) of PMFMs and PMLIs were investigated. The frequency and distribution of DLRs in PMFMs along with root canal configurations of PMLIs were assessed ipsilaterally and contralaterally. Multivariable logistic regression analysis was used to evaluate the correlation between the root canal configurations of PMLIs with the appearance of a DLR in PMFMs. Results The prevalence of PMFMs with a DLR was 24.3%, and the incidence of complicated root canal configurations in PMLIs was 25.0%. The most prevalent root canal systems of PMLIs were Vertucci types I (75%) and III (23.0%). The incidence of complicated root canal configurations in PMLIs was 19.5% in the non-DLR group (ie, no DLR was found on either side of the PMFMs), 33.3% in the unilateral DLR (Uni-DLR) group (ie, a DLR was found in 1 of the PMFMs [the left or right side] and a DLR was not found on the other PMFM), and 39.8% in the bilateral DLR (Bil-DLR) group (ie, a DLR was found in both the right and left PMFMs). After adjusting for categoric variables including sex, age, and side, the odds ratios for the frequency of complicated root canal configurations of PMLIs in the Uni-DLR and Bil-DLR groups compared with the non-DLR group were 2.12 (P = .003) and 2.707 (P Conclusions The simultaneous appearance of DLRs in PMFMs and complicated root canal configurations in PMLIs is prominent in Taiwanese individuals. Clinicians should be aware of the correlation between the anatomic variants of PMFMs and PMLIs, which are important before endodontic treatment.