Introduction: Although technology‐based learning (TB learning) has been accepted as an efficient educational tool in the field of dentistry, the evaluation of TB learning in non‐prepared situations such as pandemics has not been fully investigated. This study aimed to evaluate different aspects of TB learning amongst undergraduate dental students during the pandemic outbreak of COVID‐19.Materials and Methods: Dental students in selected Iraqi universities (University of Baghdad, University of Sulaimani and Dijlah University College) were invited to join the study. A questionnaire was created using a Google platform and answered by students. Satisfaction and attitude towards TB learning plus total evaluation scores for lecturers were examined.Results: A total of 832 out of 1800 dental students participated in the study. The majority of participants have basic (40.7%) and intermediate (47.5%) computer skills, and more than half of them lack any experience in TB learning. The overall satisfaction and positive attitude towards TB learning were less than 50%. Students at final grade, with advanced computer skills and TB learning experience, showed higher satisfaction (OR: 3.031, 2.876, 3.644, respectively) and a more positive attitude (OR: 3.172, 3.035, 3.477, respectively) towards TB learning than those at earlier grades. Total evaluation scores for lecturers were higher amongst females (11.5 ± 5.8) than males (9.9 ± 7.2) as well as amongst participants at final grade (14.0 ± 6.2), with advanced computer skills (13.8 ± 6.1) and TB learning experience (16.2 ± 6.0).Conclusions: Dental students demonstrated low‐moderate satisfaction and positive attitude towards TB learning and the quality of material presented to them. Integrating TB learning into the dental education curriculum is an essential step in enhancing the acceptance of TB learning in the future.

Porphyromonas gingivalis , a key periodontal pathogen, is capable of invading a variety of cells, including oral keratinocytes, by exploiting host cell receptors, including alpha-5 beta-1 (α5β1) integrin. Previous studies have shown that P. gingivalis accelerates the cell cycle and prevents apoptosis of host cells, but it is not known whether the cell cycle phases influence bacterium-cell interactions. The cell cycle distribution of oral keratinocytes was characterized by flow cytometry and BrdU (5-bromo-2-deoxyuridine) staining following synchronization of cultures by serum starvation. The effect of cell cycle phases on P. gingivalis invasion was measured by using antibiotic protection assays and flow cytometry, and these results were correlated with gene and surface expression levels of α5 integrin and urokinase plasminogen activator receptor (uPAR). There was a positive correlation ( R = 0.98) between the number of cells in S phase and P. gingivalis invasion, the organism was more highly associated with cells in S phase than with cells in G ₂ and G ₁ phases, and S-phase cells contained 10 times more bacteria than did cells that were not in S phase. Our findings also show that α5 integrin, but not uPAR, was positively correlated with cells in S phase, which is consistent with previous reports indicating that P. gingivalis invasion of cells is mediated by α5 integrin. This study shows for the first time that P. gingivalis preferentially associates with and invades cells in the S phase of the cell cycle. The mechanism of targeting stable dividing cells may have implications for the treatment of periodontal diseases and may partly explain the persistence of this organism at subgingival sites.

Objectives Epithelial–mesenchymal transition (EMT) is a process that shifts cellular phenotype. It is linked to several different inflammatory diseases including periodontitis. This study was conducted to investigate the involvement of the EMT process in an experimental periodontitis (EP) model. Materials and Methods Second upper molars of Wistar albino male rats were ligated to induce periodontitis, while controls were not ligated. The animals were sacrificed after 0, 3, 7, 14, and 21 days (n = 6 for each time point). The maxillae were resected, posterior to the incisor teeth, and the gingival tissue surrounding teeth were analyzed. Alveolar bone loss (ABL), epithelial thickness, and the number of inflammatory cells were measured at each time point. Expressions of EMT-related biomarkers (E-cadherin, N-cadherin, Snail1, Twist1, and vimentin) were assessed using the immunohistochemical technique. All experiments were performed in triplicate. Statistical Analysis Inferential comparisons were performed by the kruskall-wallis test. To determine the correlation between the dependent and independent variables ,Spearman's correlation test was used. Results ABL, epithelial thickness, and inflammatory cell count were gradually increased throughout the EP study period. Switching of E-cadherin/N-cadherin was evident and associated with increased nuclear expression of Snail1 and Twist1. Additionally, positive cytoplasmic expression of vimentin was detected from day 7 and increased at subsequent time points. Histoscore of E-cadherin was negatively and significantly correlated with N-cadherin and Snail1. Furthermore, Snail1 and Twist1 histoscores were significantly and positively correlated. Conclusion The results demonstrated induction of an EMT phenotype in the EP model. This was supported by cadherin switching and positive vimentin expression along with nuclear translocation of Snail1 and Twist.

Background: Amoxicillin-clavulanic acid (Augmentin®), Metronidazole, Amoxil/Metro combination, and Azithromycin are commonly utilized as adjunctive treatment of periodontitis. Moringa oleifera L (Mo) leaves extracts have demonstrated the ability to inhibit the growth of facultative anaerobic bacteria including Porphyromonas. gingivalis (P. gingivalis), Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus, Shigella sonnei, Staphylococcus aureus, Bacillus subtilis, Beta-hemolytic streptococcus, Bacillus megaterium as well as dental biofilm development. Objectives: The present study was set out to determine the antibacterial efficacy of Amoxicillin-clavulanic acid (Augmentin®), Metronidazole and Ethanolic extract of Mo leaves against P. gingivalis clinical isolate. Materials and Methods: The minimum inhibition concentrations (MIC), minimum bactericidal concentrations (MBC), and sensitivity of the clinical isolated P. gingivalis against Mo ethanolic leaves extracts, Augmentin, and Metronidazole were determined using two-fold serial dilution, agar well diffusion, and disk diffusion, respectively. The gas chromatography–mass spectrometry (GC-MS) was used for phytochemical analysis of the Mo leaves extract using ethanol solvent. Results: P. gingivalis exhibited inhibition to Mo leaves extract, while it demonstrated resistance to Augmentin and Metronidazole. MIC and MBC of Mo leaves extract were found to be 0.78 mg/ml and 1.56 mg/ml against P. gingivalis, respectively. The extract had highest anti-biofilm effect at the minimum concentrations of 1.55 mg/ml and 0.78 mg/ml equivalent to 0.06% Chlorhexidine compared to its lowest conc at 0.34 mg/ml, and this activity was inversely proportional to the extract’s concentration. Conclusion: While Augmentin and Metronidazole showed no sensitivity against P. gingivalis, the promising antibacterial effect of Mo leaves extract against this bacterium may indicates its potential for use in oral health promotion, suggesting further in vivo studies to validate Mo extracts as alternative adjuncts in periodontitis therapy.

The combination of an aqueous extract of green tea (GT) and Salvadora persica L. (SP) was proved to prevent the growth of Gram +ve facultative anaerobes and reduce biofilm formation on teeth surfaces. Porphyromonas gingivalis (P. gingivalis) is amongst the red complex pathogenic bacteria that cause periodontal disease. Thus, the aim of the current study was to examine the antibacterial and antibiofilm effects of the above combination in reducing the growth of P. gingivalis. Subgingival dental biofilm samples were collected from patients with severe periodontitis to isolate and confirm the presence of P. gingivalis. Gas mass chromatography-mass spectrometry was used for phytochemical analysis. The maceration method was used to extract the GT and SP. Disc diffusion and broth dilution methods were performed to determine antibacterial and minimum inhibitory concentrations (MIC) of SP, GT aqueous extract, and their combination in contrast to clinically isolated P. gingivalis. Further, the antibiofilm activity of the extracts and their combination was assessed using the tube adhesion technique. The findings showed that only the GT aqueous extract was effective against P. gingivalis, while the SP aqueous extract demonstrated no effectiveness. The MIC of GT was 6.25mg/mL. The aqueous extract of SP showed a greater antibiofilm effect than the aqueous extract of GT at the lowest concentrations of 6.25mg/mL and 12.5mg/mL, respectively. In conclusion, the antibacterial property of the SP and GT extracts combination against P. gingivalis was attributed to GT only. While SP extract displayed no inhibitory role against P. gingivalis, it could potentially reduce the biofilm attachment of P. gingivalis better than GT extracts.