Removal of the root canal smear layer using Carisolv III and sodium hypochlorite.

The present study investigated the effectiveness of a Carisolv III + 0.5% sodium hypochlorite (NaOCl)-based root canal irrigant for smear layer removal.Forty maxillary incisors were randomly divided into 4 groups (n = 10 per group). The canals in group A (experimental) were prepared with 0.5% NaOCl, and Carisolv III and 0.5% NaOCl was used for the final washing; groups B and C (positive controls) used 2% and 5.25% NaOCl, respectively; and group D (negative control) used phosphate-buffered saline (PBS). Ethylenediaminetetraacetic acid (EDTA) was used for all of the groups. A 5-point scoring scale and scanning electron microscopy were used to evaluate the effectiveness of the irrigants. The canals were consistently cleaner in the coronal and middle thirds than in the apical thirds (P < .05).For cleaning the root canals, 5.25% NaOCl was more effective than 2% NaOCl, 0.5% NaOCl + Carisolv III, and phosphate-buffered saline , respectively (P < .05). The 2% NaOCl solution showed similar results to 0.5% NaOCl + Carisolv III (P > .05). The combination of 5.25% NaOCl and 17% EDTA remains the most effective irrigant for removal of the root canal smear layer.A combination of Carisolv III + 0.5% NaOCl (with 17% EDTA) showed a cleaning ability similar to that of 2% NaOCl (with 17% EDTA).

Root canal morphology of maxillary and mandibular first premolars analyzed using cone-beam computed tomography in a Shandong Chinese population.

The aim of this study was to explore the root morphology and root canal configuration of first premolars among Shandong Chinese residents using cone-beam computed tomography (CBCT).Randomly selected CBCT images were collected from 648 patients (44% women, 56% men). In total, 1268 maxillary and 1296 mandibular first premolars were analyzed. The number of roots and the canal configuration were recorded and identified based on Vertucci's classification.The majority of the maxillary first premolars had 1 root (67.4%), followed by 2 roots (32%). A 2-canal configuration (89%) was the most prevalent observation. For mandibular first premolars, 98.8% had 1 root and 81% presented the type I configuration. There were no statistical differences in the number of roots or morphology in terms of the left/right side or sex (P > .05).Among Chinese residents, the majority of maxillary first premolars had 1 root and 2 canals, whereas the most common anatomical configuration for mandibular first premolars was 1 root with 1 canal.

Berberine Promotes Osteogenic Differentiation of Human Dental Pulp Stem Cells Through Activating EGFR-MAPK-Runx2 Pathways.

Similar to the mesenchymal stem cells (MSCs), dental pulp stem cells (DPSCs) also have pluripotent differentiation characteristic and may be more ideal for tissue regeneration, especially in tooth regeneration engineering. However, bacterial infection may be a powerful obstacle. Berberine (BBR), known with antibacterial effects, was recently found to play functions in bone formation through promoting osteogenic differentiation from pluripotent stem cells. However, whether BBR also function in DPSCs osteogenic differentiation has not yet been reported. Primary DPSCs were isolated from dental pulp tissues extracted from human impacted mandibular third molars, and identified by flow cytometry for cell surface antigen molecules. A dexamethasone osteogenic medium was used to induce DPSCs osteogenic differentiation. BBR (1 µM and 5 µM) was pre-added to into medium, and then cell proliferation, spheroid formation and osteogenic differentiation capacities of DPSCs were analyzed, as well as the underlying molecules modulation mechanism. Flow cytometry identified that CD44, CD90, CD81 and CD105 positively expressed in the isolated hDPSCs, with CD34 and CD45 negetively expressed. BBR enhanced the cell proliferation of hDPSCs in a dose-dependent pattern, and promoted dexamethasone-induced osteogenic differentiation via enhancing Runx2 transcription factor activity followed by upregulating osteogenesis markers expression, whereas the adipogenic differentiation of hDPSCs was suppressed dramatically by BBR. The EGFR and MAPK pathways were activated by BBR, and inhibitors for these pathways significantly suppressed the osteogenic differentiation promotion of BBR. These results have revealed a novel mechanism that berberine might promote hDPSCs osteogenic differentiation through activating EGFR-MAPK-Runx2 signaling pathways.

ADAM28 dramatically regulates the biological features of human gingival fibroblasts.

This study was to explore the effects of a disintegrin and metalloproteinase 28 (ADAM28) on the proliferation, differentiation, and apoptosis of human gingival fibroblasts (HGFs) and probable mechanism. After ADAM28 antisense oligodeoxynucleotide (AS-ODN) and sense oligodeoxynucleotide (S-ODN) were transfected into HGFs by Lipofectamine 2000, respectively, the expression discrepancies of ADAM28 among various groups were evaluated by reverse transcription-polymerase chain reaction (RT-PCR) and Western-blotting. Methabenzthiazuron (MTT) and cell-cycle assays were used to test the HGFs proliferation activity. Annexin V fluorescein isothiocyanate (FITC)/propidium iodide (PI) and alkaline phosphatase (ALP) analysis were performed separately to measure apoptosis and the cytodifferentiation standard. Immunocytochemistry and Western-blotting were carried out to determine the influence of ADAM28 AS-ODN on HGFs expressing core binding factor α1 (Cbfα1), cementum protein 1 (CEMP1), osteopontin (OPN) and dentin matrix protein 1 (DMP1). The AS-ODN group displayed the lowest expression level in HGFs, meanwhile the ADAM28 S-ODN group showed the highest. Furthermore, blocking of ADAM28 could inhibit the proliferation of HGFs, enhance HGFs differentiation and induce apoptosis of HGFs. Whereas, overexpression of ADAM28 generated the opposite effects and inhibited apoptosis. ADAM28 AS-ODN was able to notably suppress the expressions of Cbfα1 and CEMP1, and ADAM28 had positive correlations with cbfα1 and CEMP1. These provided conspicuous evidence that ADAM28 may play a crucial role in root development as a potential regulator of growth, differentiation, and apoptosis of HGFs.

[Maxillary first premolar with four canals: a case report].

This article presented a case of discovering and diagnosing three roots with four canals of the maxillary first premolar. We found and located the extra root canal by clinical diagnosis, careful observation during the operation, and multiangle X-ray. We further confirmed the existence of the three roots with four canals with the help of cone-beam computed tomography. Finally, we verified the success of the high-quality root-canal therapy through root optical microscopy.

miR-140-5p-mediated regulation of the proliferation and differentiation of human dental pulp stem cells occurs through the lipopolysaccharide/toll-like receptor 4 signaling pathway.

Human dental pulp stem cells (DPSCs) are oral mesenchymal stem cells with potential to differentiate into various cell types. Recent studies of DPSCs have focused on microRNAs (miRNAs), a class of small noncoding RNAs that play crucial roles in regulating DPSC phenotypes. In the current study, the expression of miR-140-5p was significantly decreased during lipopolysaccharide (LPS)-mediated differentiation of DPSCs in vitro. Overexpression of miR-140-5p enhanced proliferation of DPSCs and inhibited DPSC differentiation, whereas suppression of miR-140-5p produced the opposite effect. Moreover, the expression of toll-like receptor 4 (TLR-4), a critical regulator of DPSCs, was negatively correlated with the levels of miR-140-5p. A luciferase reporter analysis confirmed that miR-140-5p could regulate TLR-4 by directly binding to the 3'-untranslated region (3'-UTR) of the TLR4 mRNA. Additionally, we suppressed TLR-4 expression by treating cells with a TLR-4 inhibitor, CLI-095, and demonstrated that the effect of the miR-140-5p inhibitor on DPSC proliferation and differentiation could be partially reversed by blocking TLR-4. Taken together, our data suggest that miR-140-5p is a novel miRNA that regulates DPSC proliferation and differentiation.