Purpose: This study aimed to carry out a city-wide survey to evaluate undergraduate students' opinions on their oral surgery training by measuring their self-confidence. Materials and Methods:A cross-sectional survey of 383 3rd year, 412 4th year and 363 5th year undergraduate dental students from six dental schools in Istanbul with a mean age of 22.73 ± 1.55 was conducted towards the end of the academic year. A web link to the questionnaire was sent to the contact person at the participating dental schools. The questionnaires were anonymously evaluated. Descriptive statistics were calculated, and Chi-square tests were performed to examine the data. A P-value of <.05 was considered to be statistically significant. Results:In total, 1158 responses were returned, representing 67% of the overall students in the 2018-2019 academic year. The male respondents were significantly more self-confident than females in the general aspects of surgical skills. More than half of the respondents (53%) felt confident in oral surgery knowledge to undertake independent practice. Although 5th year respondents felt more confident in the general aspect of the questionnaire, their ability of differentiation of odontogenic and non-odontogenic pain was lower than their counterparts. The majority (86%) of the participants disagreed that the only knowledge required for oral surgery was that of tooth and jaw anatomy. Conclusion:This survey revealed perceived confidence in tooth and retained root extraction. The male respondents were found to be more self-confident. There is a need for improvement in surgical skills, recognition of malignancies and differentiation of the origin of the pain. K E Y W O R D Sanatomical knowledge, dental students' opinion, oral surgery teaching, self-confidence

Objective: This study evaluated the angiogenesis-enhancing potential of a tricalcium silicate-based mineral trioxide aggregate (ProRoot MTA), Biodentine, and a novel bioceramic root canal sealer (Well-Root ST) in human dental pulp stem cells (hDPSCs), human periodontal ligament stem cells (hPLSCs), and human tooth germ stem cells (hTGSCs). Methodology: Dulbecco's modified Eagle's medium was conditioned for 24 h by exposure to ProRoot MTA, Biodentine, or Well-Root ST specimens (prepared according to the manufacturers' instructions). The cells were cultured in these conditioned media and their viability was assessed with 3-(4,5-dimethyl-thiazol-2-yl)-5-(3-carboxy-methoxy-phenyl)-2-(4-sulfo-phenyl)-2H tetrazolium (MTS) on days 1, 3, 7, 10, and 14. Angiogenic growth factors [platelet-derived growth factor (PDGF), basic fibroblast growth factor (FGF-2), and vascular endothelial growth factor (VEGF)] were assayed by sandwich enzyme-linked immunosorbent assay (ELISA) on days 1, 7, and 14. Human umbilical vein endothelial cell (HUVEC) migration assays were used to evaluate the vascular effects of the tested materials at 6-8 h. Statistical analyses included Kruskal-Wallis, Mann-Whitney U, and Friedman and Wilcoxon signed rank tests. Results: None of tricalcium silicate-based materials were cytotoxic and all induced a similar release of angiogenic growth factors (PDGF, FGF-2, and VEGF) (p>0.05). The best cell viability was observed for hDPSCs (p<0.05) with all tricalcium silicate-based materials at day 14. Tube formation by HUVECs showed a significant increase with all tested materials (p<0.05). Conclusion: The tricalcium silicate-based materials showed potential for angiogenic stimulation of all stem cell types and significantly enhanced tube formation by HUVECs.

The aim of the present study was to assess the systemic effect of thymoquinone (TQ) on bone healing by starting TQ administration, either 40 days before, or on the day of the surgical procedure and continuing during the healing period of 28 days. Eighteen experimental rats were divided into three groups and defects were created in their tibias. The following procedures were performed for each group: Control group (C): No systemic drug administration (n D 6); Test group 1 (T1): Systemic TQ was administered daily starting 40 days before creation of the defect and additionally during the post-operative healing period of 28 days (n D 6); Test group 2 (T2): Systemic TQ was administered daily after creation of the defect and during the healing period of 28 days (n D 6). Quantitative measurement for new bone formation, osteoblast lining and semi-quantitative measurement of capillary intensities were examined and statistically analysed. There was a significant increase in the ratio of new bone per total defect area and new bone trabeculae lined by active osteoblasts in both test groups (T1 and T2) compared to control group (p < 0.05). However the difference between T1 and T2 was not statistically significant. TQ-administered groups also showed an increase in capillary intensity in the defect area compared to the control group (p < 0.05). Systemic administration of TQ either starting 40 days before or on the day of surgery accelerated new bone formation in a rat model and can be advocated as an adjunct to expedite bone healing.

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Neogenesis of osseous and ligamentous interfacial structures is essential for the regeneration of large oral or craniofacial defects. However, current treatment strategies are inadequate in renewing supporting tissues of teeth after trauma, chronic infections or surgical resection. Combined use of 3D scaffolds with stem cells became a promising treatment option for these injuries. Matching different scaffolding materials with different tissues can induce the correct cytokines and the differentiation of cells corresponding to that particular tissue. In this study, a hydroxyapatite (HA) based scaffold was used together with human adipose stem cells (hASCs), human bone marrow stem cells (hBMSCs) and gingival epithelial cells to mimic human tooth dentin-pulp-enamel tissue complexes and model an immature tooth at the late bell stage in vitro. Characteristics of the scaffold were determined via SEM, FTIR, pore size and density measurements. Changes in gene expression, protein secretions and tissue histology resulting from cross-interactions of different dental tissues grown in the system were shown. Classical tooth tissues such as cementum, pulp and bone like tissues were formed within the scaffold. Our study suggests that a HA-based scaffold with different cell lineages can successfully mimic early stages of tooth development and can be a valuable tool for hard tissue engineering.

Purpose: The aim of this study is to compare effects of postoperative care agents; chlorhexidine, octenidine dihydrochloride and hyaluronic acid on human gingival fibroblasts’ viability, proliferation, apoptosis and migration. Materials and methods: After cell culturing; chlorhexidine, octenidine dihydrochloride and hyaluronic acid solutions were applied on cells and nothing was applied for control group. The cells were monitored to investigate cytotoxicity; the percentage of apoptotic, living and dead cells at the time of 24, 48, and 72 hours (h). A scratch wound assay was performed to detect cell migration and cells were monitored at baseline, at 24 and 48h. Results: At 24h, chlorhexidine showed statistically lower percentage of total apoptotic cells’ than octenidine dihydrochloride (p=0.049), hyaluronic acid (p=0.049) and control (p=0.049). At 48h, hyaluronic acid showed statistically lower percentage than chlorhexidine (p=0.049), and control (p=0.049). All agents were found to have statistically and significantly more cytotoxic than control. However, there was no difference between experimental groups for proliferation rate. Octenidine dihydrochloride showed statistically negative effects on cell migration than chlorhexidine and hyaluronic acid at 24h. Chlorhexidine and hyaluronic acid maintained migration ability of cells than octenidine dihydrochloride at 48h. Conclusion: All agents have similar effects on cell behavior such as viability, apoptosis and cell proliferation. However, octenidine dihydrochloride showed statistically negative effects on migration ability than chlorhexidine and hyaluronic acid.

Purpose This study was performed to evaluate the influence of local application of thymoquinone (TQ) on bone healing in experimental bone defects infected with Porphyromonas gingivalis (PG). Methods Forty-two female rats were randomly divided into 6 groups. A bone defect was created on the right tibia of all animals. The PG, PG/collagen membrane (COL) and PG/TQ/COL groups were infected with PG. In the COL and PG/COL groups, the defects were covered with a COL; in the TQ/COL and PG/TQ/COL groups, the defects were covered with a TQ-containing COL. After 28 days, all animals were sacrificed. Quantitative measurements of new bone formation and osteoblast lining, as well as semiquantitative measurements of capillary density and tissue response, were analyzed. Furthermore, the presence of bacterial infections in defect areas was evaluated. Results The new bone formation, osteoblast number, and capillary density were significantly higher in the TQ groups than in the control groups ( P <0.001, P <0.001, and P <0.01, respectively). In a comparison between the TQ/COL group, with a TQ-containing COL (TQ/COL), and the PG – infected TQ-containing COL (PG/TQ/COL) group, the newly formed bone and capillary density were higher in the TQ/COL group ( P <0.01). When the control group was compared to the PG, PG/COL, and PG/TQ/COL groups in terms of tissue response, the differences were statistically significant ( P <0.001, P =0.02, and P =0.041, respectively). The intensity of the inflammatory cell reaction was higher in the PG, PG/COL, and PG/TQ/COL groups ( P <0.05). Conclusions Within the limitations of this study, the local application of a TQ-containing COL positively affected bone healing even if the bone defects were infected. The results suggest that TQ increased angiogenesis and showed promise for accelerating bone defect healing. Further research is warranted to support these findings and reach more definitive conclusions.

Bu olgu raporunun amacı; açılı vida kanallı ti-base abutmantlarla desteklenen hibrit abutmant kuronların kullanım amacı ve avantajlarını açıklamaktır. İmplant dişhekimliği'nde açılı vida kanallı abutmantlar, açılı implantlar üzerine uygulanan vidalı kuronlarda estetik bölgede vida kanalının gözükmesi problemine çözüm olarak üretilmişlerdir. Ayrıca, açılı vida kanallı ti-base abutmantlarla oluşturulan hibrit abutmant kuronlar, anterior tek diş implant restorasyonlarında estetik ve mekanik direnç avantajlarını birleştirilen bir yöntem olarak da düşünülebilir. Hibrit abutmant kuron dizaynında açılı vida kanalı sisteminin kullanımı, fazla açılı yerleştirilmiş implantların vidalı kuronlar ile restorasyonunda klinisyenlere optimal estetik ve dayanıklılık avantajlarını sunar.