European Journal of Dentistry最新文献

This study aimed to evaluate whether adopting a horizontal viewpoint, facilitated by a novel digital assistive device, could enhance endodontic file placement accuracy and reduce operator-dependent variability during root canal treatment.A total of 40 modified upper jaw dental stone models, each accommodating a plastic tooth replacing the upper right second molar, were divided into two groups (n = 20 each). The mesiobuccal canal of each tooth was prepared to a standardized working length of 21.0 mm and a working width of size 35. A size 40 file with a stopper preadjusted to 19.0 mm was then inserted. In the first (conventional) group, files were placed without assistance; in the second (device-assisted) group, a horizontal-view digital device was designed, developed, and used to align and insert the file. The second operator, blinded to the device's purpose, performed all insertions under simulated clinical conditions. An intraoral scanner subsequently captured the vertical distance from the stopper's bottom surface to a standardized anatomical landmark. Pairwise comparisons between the two groups were computed using alignment software to account for potential measurement artifacts.Normality in both groups was confirmed via the Shapiro-Wilk test. An independent-samples t-test compared mean vertical distances. Additionally, differences in stopper positioning were calculated for all aligned virtual models in CloudCompare.The device-assisted group exhibited a significantly shorter mean stopper-to-landmark distance (0.425 mm, standard deviation [SD] = 0.225) than the conventional group (0.971 mm, SD = 0.432) (t = -5.014, p = 2.534 × 10^-5). Pairwise analysis highlighted closer apical positioning in the device-assisted group, closely matching pilot study findings that a 26.57° vertical viewing angle can distort perceptions by 0.5 mm. The device's mean intraoral mounting time was 224 s (SD = 35.2), considered negligible over the full treatment duration.Adopting a horizontal perspective with a novel digital assistive device significantly improved file placement accuracy and reduced operator-dependent variability during root canal treatment. Optimizing this device's design and assessing its cost-effectiveness may facilitate broader clinical adoption and further enhance endodontic procedural outcomes.

Certain factors that disturb the tumor microenvironment influence the promotion of tumorigenesis. Detecting gene expression at the protein level is highly valuable and complements the histopathological analysis achieved by immunohistochemistry (IHC). Hypoxia-inducible factor (HIF)-1α accomplishes autophagy induction and regulation of autophagy-associated genes. So, this study was carried out to evaluate the tissue protein expression of Beclin-1 and HIF-1α using IHC and correlate their expression with the prognosis of oral squamous cell carcinoma (OSCC).Immunohistochemical evaluation of Beclin-1 and HIF-1α was done in 5 samples of normal oral epithelial tissues and 45 samples of OSCC, which were classified histologically into 15 samples each of well, moderately, and poorly differentiated squamous cell carcinoma.According to statistics, normal tissue had the highest values for Beclin-1, while poorly differentiated OSCC had the lowest mean area percentage. HIF-1α showed the opposite results. These results indicate that the association of both molecules has a greater role in the transformation from normal to different histopathological grades of OSCC.The close association between Beclin-1 and HIF-1α identified in the current study confirms hypoxia's critical role in autophagy activation. Moreover, reduced Beclin-1 and elevated HIF-1α expression were significantly associated with the histopathological grading of OSCC, supporting their pivotal role in the development and progression of OSCC.

The release of growth factors in injectable platelet-rich fibrin (I-PRF) exhibits a peak within 24 hours and subsequent decline by day 10, underscoring immediate application, limiting its effectiveness in alveolar bone repair. In order to enhance its regenerative potential, I-PRF can be combined with biomaterial scaffolds such as collagen-chitosan hydrogels, which mimic the extracellular matrix and support tissue regeneration. This combination has been shown to enhance cellular signaling and tissue repair. This study aimed to analyze the characterization of collagen-chitosan hydrogels with I-PRF and determine the growth factor release pattern that occurs after mixing.Collagen-chitosan hydrogels were prepared and combined with I-PRF at a 1:1 ratio. The structural characterization of these hydrogels, both with and without I-PRF, was performed using Fourier transform infrared spectroscopy (FTIR), enabling the comparison of absorption bands. Furthermore, the release profiles of transforming growth factor-beta 1 (TGF-β1) and platelet-derived growth factor AB (PDGF-AB) were assessed in two experimental groups: The first group consisted of I-PRF alone, while the second group comprised of I-PRF combined with collagen-chitosan hydrogels. Growth factor release was evaluated at multiple time points (days 1, 3, 5, 7, 9, 11, 13, 15, and 17) using enzyme-linked immunosorbent assay. The resulting absorbance values were converted into concentration measurements (pg/mL) using a standard calibration curve. Statistical analysis was conducted using two-way analysis of variance followed by a post hoc least significant difference test.FTIR analysis demonstrated that the functional groups present in the collagen-chitosan hydrogel remained unchanged following the incorporation of I-PRF, confirming the formation of physical rather than chemical bonds. Subsequent analysis revealed statistically significant differences in the release patterns of TGF-β1 and PDGF-AB between the two groups (p < 0.05). The combination of collagen-chitosan hydrogel and I-PRF exhibited a more stable and sustained release profile from day 1 to day 17.The combination of I-PRF with collagen-chitosan hydrogels does not alter the fundamental chemical structure of the scaffold. However, this combination does influence the controlled release of growth factors. This finding indicates that the synergistic interaction between collagen and chitosan enhances the hydrogel's properties, suggesting its potential as a promising biomaterial for use as a scaffold in bone regeneration.

The objectives were to synthesize a bioactive nanocomposite as an endodontic antimicrobial agent by loading previously synthesized electrosprayed chitosan nanoparticles (Ch-Np) into Zeolite-Y as a carrier and compare its antimicrobial activity against two endodontic pathogens using the agar diffusion test. Additionally, the effect of tissue inhibitors (dentin powder and serum albumin) on the antimicrobial activity of the Ch-Np-Zeolite nanocomposite was studied. Finally, the possible cytotoxicity of the novel nanocomposite against Balb/c 3T3 mouse fibroblast cells was evaluated.A concentration of 3% (w/v) electrosprayed Ch-Np was mixed with Zeolite-Y in a concentration of 53.3 (w/v) and characterized using high-resolution scanning electron microscopy (HR-SEM) and energy-dispersive X-ray spectroscopy (EDS) analysis. The antimicrobial activity was evaluated against Streptococcus mutans and Enterococcus faecalis using the agar diffusion test, and the time-kill test was performed using the broth microdilution technique in the presence of tissue inhibitors. The cytotoxicity was evaluated against 3T3 mouse fibroblast cells using the standard 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.The difference between the antimicrobial activity of Ch-Np-Zeolite nanocomposite against S. mutans and E. faecalis was analyzed using the Mann-Whitney's U test. The effect of tissue inhibitors on the antimicrobial activity of Ch-Np-Zeolite nanocomposite was analyzed by comparing the mean of log colony-forming unit per milliliter over time. For the cytotoxicity assay, a statistically significant difference between each group and their control was made using a t-test with a probability value of p ≤ 0.05, considered a significant difference.HR-SEM of the dried paste-like mixture Ch-Np-Zeolite revealed the typical crystal habit of the supporting zeolite, and EDS analysis confirmed that the zeolite parent material retained its elemental composition after loading with Ch-Np. The antimicrobial activity of Ch-Np-Zeolite was demonstrated by the mean diameter inhibition zones of 9.57 and 7.85 mm for S. mutans and E. faecalis, respectively. Streptococcus mutans and E. faecalis were completely eradicated in the presence of tissue inhibitors. The Ch-Np-Zeolite nanocomposite significantly promoted the growth of 3T3 fibroblast cells (p < 0.05), supporting its lack of cytotoxicity.Zeolite-Y-loaded Ch-Np nanocomposite shows promising antimicrobial activity while maintaining its biocompatibility even in the presence of tissue inhibitors.

This study aimed to compare the push-out bond strength (POBS) of TotalFill (TFB) and AH Plus bioceramic (APB) sealers with different irrigation protocols.Sixty maxillary central incisors were prepared and randomly divided into three groups (n = 10) based on the final irrigation protocol. Group NC: 5.25% sodium hypochlorite (NaOCl); Group NE: 5.25% NaOCl and 17% EDTA; Group NH: 5.25% NaOCl and dual rinse HEDP (1-hydroxyethylidene-1,1-diphosphonic acid). Samples were obturated using either TFB or APB sealer only. In groups NC and NE, NaOCl was used during canal preparation, while in Group NH, NaOCl/HEDP was utilized. The teeth were then horizontally sectioned into three 3-mm thick sections at the apical, middle, and coronal levels. The POBS was performed on the root sections at a 1 mm/min speed. The failure mode was assessed using an optical microscope and a scanning electron microscope.Two-way ANOVA (analysis of variance) was used for statistical analysis to test the interaction between sealer type and irrigation solution, while an independent t-test was conducted to compare the means of the two sealer types at a significance level of 0.05.Specimens obturated with TFB showed significantly higher POBS than APB (p < 0.001). The highest bond strength was observed in the HEDP/TFB group and the lowest in the HEDP/APB group. Irrigation did not significantly influence the POBS (p > 0.05). Mixed failure was most commonly observed in all groups (>65%).TFB sealer had improved bond strength over APB sealer, regardless of the final irrigation protocol used, which did not significantly affect the bond strength.

Calcium silicate materials are widely used in endodontic treatment. Different calcium silicate percentages can be included in bioceramic sealers. The aim of this in vitro study was to investigate the effect of the calcium silicate percentages on mineral deposition into dentinal tubules at 7 days, 1 month, and 4 months of aging, as well as the effect of calcium silicate percentages on the quality of retreatment using two endodontic retreatment systems.Single rooted premolars were used in the present study. After the shaping and irrigation steps, the obturation was performed using high (Ceraseal "CRS") and low (AH Plus Bioceramic "AHB") calcium silicate percentage sealers. ReTreaty (RT) and ProTaper Universal Retreatment (PUR) were used to perform the retreatment process. The time required to achieve the apex was recorded. A digital microscope and a cone-beam computed tomography (CBCT) were used to evaluate the remaining materials after the retreatment procedure. Scanning electron microscope was used to investigate the presence of mineral deposition into dentinal tubules and the change in mineral morphology at 7 days, 1 month, and 4 months. The data was statistically analyzed using two-way analysis of variance and t-test.Both materials (CRS and AHB) demonstrated different mineral depositions onto their surfaces after 24 hours, 1 month, and 4 months, and showed mineral depositions into dentinal tubules at 4 months. RT was faster in achieving the apex for CRS group compared to PUR (p < 0.001), while no difference was found between both systems among the AHB groups. Both retreatment systems were quicker to achieve the apex in AHB compared to the CRS group (RT p = 0.035 and PUR p < 0.001). CBCT demonstrated a more precise measurement compared to the digital microscope in which the instrument and the material factors influence the removal ability at the coronal and middle thirds (p < 0.05). No significant difference was found at the apical third.The retreatment of AHB was easier and faster than CRS. RT demonstrated higher removal ability and faster time compared to PUR. The apical third proved to be a difficult area to achieve an optimal cleaning. Calcium silicate percentages included in bioceramic sealers could play an important role in root canal retreatment. Higher percentages of calcium silicate can decrease the capacity of the retreatment process and increase the needed time to remove the materials.

The roselle flower (Hibiscus sabdariffa) has shown potential as an alternative therapy for bone regeneration. This flower extract can induce osteoblast maturation, which is crucial for forming new bone. The study aim was to evaluate the viability of the 7F2 preosteoblast cell line following the application of a roselle flower nanoemulsion extract (RNE).This study utilized the 7F2 preosteoblast cell line to assess cell viability (%). The RNE was oven-dried at 35 to 40°C for 6 hours, resulting in a solid extract. The extract was then diluted into different concentrations. The preparation of 1% RNE was stirred at 1,400 rpm at 50°C for 90 minutes. Primary cultures of preosteoblast cell lines (7F2 cells) were distributed across 10 wells. Well 1 served as the positive control, representing 100% cell viability. Well 2 acted as the media control, containing only culture media without cells, representing 0% cell viability. Wells 3 to 10 were exposed to 1% RNE at serial concentrations of 100, 50, 25, 12.5, 6.25, 3.125, 1.56, and 0.78%. The viability of the 7F2 preosteoblast cell line was assessed using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide or microtetrazolium assay. The treatment was conducted on days 1, 3, and 7 for observation.The findings indicated that the highest cell viability was observed on day 7, averaging 89.27% at a 0.78% concentration, while the lowest viability was 2.60% at a 100% concentration.These results suggest that RNE is nontoxic to the 7F2 preosteoblast cell line.

This study aims to compare the regenerative effects of various by-products of human leukocyte platelet-rich fibrin (L-PRF), including L-PRF exudate, concentrated PRF (C-PRF), and a mixture of the two, with hyaluronic acid (HA) specifically for interdental papillae reconstruction.The L-PRF was obtained by centrifuging 10 mL of human blood in a fixed-angle centrifuge at 2,700 rpm for 12 minutes. After centrifugation, the L-PRF layer was separated, and platelet and leukocyte counts were performed. An in vivo study was conducted using Sprague-Dawley rats subjected to a modified open gingival embrasure (OGE) model for 7 days. Once the OGE was established, 20 µL of L-PRF exudate (n = 3), C-PRF (n = 3), a combination of L-PRF exudate and C-PRF (n = 3), HA (n = 3), and phosphate-buffered saline (n = 3) were injected 2 mm from the tip of the papillae using a 30G syringe. Clinical parameters, including OGE width and spring papilla distance (SPD), were observed on days 7 and 14. On day 14, histological observations included fibroblast count, blood vessel presence, epithelial width, and collagen density, while proliferating cell nuclear antigen expression was assessed immunohistochemically.The SPD on day 7, along with all histological and immunohistochemical data, were normally distributed and analyzed by one-way analysis of variance followed by Tukey's honestly significant difference test. In contrast, the Kruskal-Wallis' test was used to analyze the OGE width and SPD on day 14, which was not normally distributed.The cell counts indicated that most platelets and leukocytes were in the C-PRF layer. The L-PRF membrane by-product increased fibroblast proliferation more effectively than HA (p < 0.05). Only C-PRF significantly enhanced the vascularization and epithelialization of the papillae (p < 0.05). However, the observed cellular and molecular changes increased at day 7 postinjection and did not impact collagen density or interdental papilla height.The regenerative effect of C-PRF injection is superior to that of HA and other L-PRF by-products, as it promotes papillae regeneration by enhancing fibroblast activity, vascularization, and epithelialization. These findings show the potential impact of L-PRF by-products as a nonsurgical papillae reconstruction treatment.

Dental caries is an infectious disease that develops through biofilm. Streptococcus mutans is a cariogenic bacterium that can be found in dental plaque. Streptococcus mutans regulates biofilm formation and communicate with other microbes through a process called quorum sensing. Dental caries prevention can be achieved by inhibiting quorum sensing. This study aimed to investigate the ability of Lactobacillus plantarum and Candida albicans to inhibit the formation of S. mutans polymicrobial biofilms. This study aims to investigate the ability of biofilm formation analyzed through the crystal violet (CV) assay and bacterial metabolic activity analyzed through the methylthiazol tetrazolium (MTT) assay. The bacteria used are S. mutans (serotype C), L. plantarum (FNCC 0020), and C. albicans.CV assay results show that in the presence of L. plantarum, biofilm formation in S. mutans decreases (9.5%). Meanwhile, the formation of S. mutans biofilms increased with the presence of C. albicans (28.8%). MTT assay results showed an increase in the metabolic activity of S. mutans in the presence of L. plantarum (20.2%) and C. albicans (19.4%). Lactobacillus plantarum can inhibit the formation of S. mutans biofilms, while C. albicans can increase S. mutans biofilms.

Implants are one of the common treatments in dentistry. This treatment has various complications such as inflammation around the implant, failure of the coating, and screw loosening. Several factors contribute to screw loosening, including abutment type and collar height. Therefore, this study aims to compare the amount of loosening in two types of abutments-InOcta and SynOcta abutments.In this laboratory study, 20 titanium fixtures of the Dentis brand were divided into two groups. Each group consisted of 10 fixtures. The fixtures were mounted vertically in acrylic blocks with dimensions of 20 × 6 × 10 mm. After installing the SynOcta and InOcta abutments, the screws were torqued to 30 N·cm and re-torqued after 10 minutes. Subsequently, the samples were transferred to a chewing simulator. A compressive force of 90 N was applied for 10,000 cycles at a frequency of 75 rpm. After loading, the torque required to loosen the screws was measured, and the loosening torque was calculated. The data were analyzed using an independent t-test, and a significance level (p-value) of less than 0.05 was considered.The mean de-torque for the tissue level InOcta abutments was calculated to be 25.75 N.cm, while the mean de-torque for the SynOcta abutments was 21.98 N.cm. A comparison using the t-test showed that the mean de-torque for the InOcta abutment group was significantly higher than the SynOcta group (p < 0.001).The final results of the experiments indicate that under laboratory conditions, the de-torque of the abutment screw in the tissue level SynOcta group is significantly lower than that in the InOcta group (p < 0.001).