Selma Jakupović

Alkasites are resin-based restorative materials that differ from conventional resin composites in the composition and reactivity of their filler system, which enables ion release. Whether optional light activation changes the mechanical properties of the alkasite Cention Forte, compared with self-curing and with a conventional composite, remains insufficiently documented. This in vitro study compared Cention Forte (urethane dimethacrylate-based matrix; reactive calcium fluorosilicate and barium glass fillers) in self-cured (G1) and light-cured (G2) modes with the nanohybrid composite Tetric EvoCeram (G0; dimethacrylate matrix; barium glass, ytterbium trifluoride, mixed oxide and prepolymerized fillers). Top- and bottom-surface Vickers microhardness (VMHt, VMHb), bottom-to-top ratio (BTR), diametral tensile strength (DTS) and compressive strength (CS) were measured (n = 7). G1 showed the highest VMHt (70.3 HV), followed by G0 (63.0 HV) and G2 (57.8 HV) (p< 0.001). Both Cention Forte groups had BTR values of approximately 1.00 (G0: 0.97) as an indirect, surface-based index. G2 exhibited the highest DTS (39.7 MPa) and G0 the highest CS (311.2 MPa). Curing mode accounted for most between-group variance in microhardness, whereas material composition dominated compressive strength.

Uvod: Konusno-snopna kompjuterizirana tomografija (CBCT) predstavlja radiološku dijagnostičku metodu koja omogućava trodimenzionalni prikaz anatomskih struktura maksilofacijalne regije uz visoku prostornu rezoluciju i manju dozu zračenja u odnosu na klasični CT. Poseban značaj CBCT-a ogleda se u analizi mandibule i sitnih anatomskih struktura koje često nisu jasno vidljive na konvencionalnim radiografskim snimcima. Cilj: Prikazati dijagnostički značaj CBCT-a u analizi mandibule i sitnih anatomskih struktura kroz pregled dostupne literature. Materijal i metode: Pregledni rad zasnovan je na analizi dostupne stručne i naučne literature u elektronskim bazama podataka (PubMed/MEDLINE, Scopus, Web of Science, Google Scholar). Korištene su ključne riječi: CBCT, mandible, mandibular canal, mental foramen, lingual foramina. Rezultati: Analiza dostupne literature pokazuje da CBCT omogućava visoko preciznu identifikaciju anatomskih struktura mandibule i njihovih međusobnih odnosa. U poređenju sa panoramskim i intraoralnim radiografskim snimcima, metoda se odlikuje značajno većom dijagnostičkom tačnošću i superiornom vizualizacijom anatomskih varijacija. Posebna vrijednost CBCT-a ogleda se u unapređenju preoperativnog planiranja implantoloških i oralnohirurških zahvata, kao i u smanjenju rizika od neurovaskularnih komplikacija. Zaključak: CBCT predstavlja superiornu i visoko pouzdanu dijagnostičku metodu u analizi mandibule i njenih anatomskih struktura, uključujući mandibularni kanal, mentalni foramen i lingvalne otvore, jer omogućava preciznu trodimenzionalnu vizualizaciju bez superpozicije i distorzije. Njegova primjena značajno unapređuje preoperativno planiranje implantoloških i oralnohirurških zahvata, uz smanjenje rizika od neurovaskularnih i hemoragijskih komplikacija. Zbog visoke dijagnostičke tačnosti i mogućnosti detaljne anatomske evaluacije, CBCT ima ključnu ulogu u savremenoj stomatološkoj dijagnostici mandibularne regije.

Introduction: Medical students, including dental students, are more likely to be burdened with depression, anxiety, burnout, and anorexic tendencies than their peers studying other subjects. In spite of major public health relevance, there is a large knowledge gap regarding mental health issues among Bosnian dental students. The aim of this research is to estimate the depression prevalence among dental students in Sarajevo according to age, gender, and academic year. Methods: A cross-sectional study was conducted among 1st, 3rd, 4th, and 6th year students at the Dental School, University of Sarajevo, during 2023-2024. Depression was evaluated using the self-reported patient health questionnaire-9 (PHQ-9). Statistical analysis included the Shapiro–Wilk test, with data presented as means with standard deviations (SDs), medians (Mdn) with interquartile ranges (IQRs), and frequencies. Comparisons between males and females were analyzed using the Student’s t-test or Mann–Whitney U-test and one-way analysis of variance or Kruskal–Wallis test across academic years. Results: In the total sample (n = 324), females outnumbered males, 244 versus 80. Clinically significant depression (PHQ-9 ≥10) was reported in 52.79% of students. The average PHQ-9 value was Mdn = 10.00, IQR (6.00, 16.00), M = 11.1, SD = 6.66. The highest average PHQ-9 values were observed in the 4th year and the lowest in the 6th year. Female students had significantly higher average PHQ-9 scores (p < 0.05). Conclusion: Dental students in Sarajevo exhibited high depression prevalence, but female students were more affected. These findings emphasize an urgent need for targeted mental health interventions in dental education.

Background: The study investigates newly developed composite materials with advanced filler technology and modified resin matrices, designed to enhance esthetic quality, clinical efficiency, and mechanical properties. This study evaluated the effect of two light-curing protocols—a conventional low-voltage (LV) protocol (10 s at 1200 mW/cm²) and a high-voltage (HV) protocol (3 s at 3000 mW/cm²)—on the microhardness (MH), bottom/top MH ratio, and the correlation between filler content (wt%, vol%) and MH of bulk-fill resin-based composites (RBCs). Four RBCs were tested: Tetric PlusFill (TPF), Tetric Plus Flow(TPFW), Tetric PowerFill (PFL), and Tetric PowerFlow (PFW). Materials and Methods: Samples were fabricated in the laboratory using specially designed cylindrical molds (diameter = 8 mm, height = 4 mm). Initial MH was measured on the top and bottom surfaces of composite specimens 24 h after light curing using a digital microhardness tester (QNESS 60 M EVO, ATM Qness GmbH, Mammelzen, Germany). The correlation between the filler content (wt%, vol%) and the MH of the RBCs was tested. For the calculation of depth-dependent curing effectiveness, the bottom/top ratio for initial MH was used. Conclusions: The MH of bulk-fill RBCs was found to be influenced by both material composition and the applied light-curing protocol. An increase in filler content resulted in higher MH values under both protocols, with the filler volume fraction exhibiting a stronger correlation than the weight fraction. While both flowable and sculptable Tetric Plus composites exhibited higher MH values under the HV protocol, Tetric Power composites demonstrated greater initial hardness under LV protocol. The flowable composite PFW showed the most pronounced reduction in MH under HV curing. The bottom/top MH ratio exceeded 80% in all tested materials, confirming adequate polymerization throughout the composite layers.

Introduction: The main purpose of root canal filling materials is to provide an apical sealing that prevents the movement of bacteria and the diffusion of their metabolic products from the root canal system to periapical tissue. The aim of this study was to evaluate the apical sealing ability of mineral trioxide aggregate’s (MTA), epoxy resin, and zinc oxide eugenol- based sealer with single cone obturation techniques using the dye extraction leakage method. Methods: Seventy-five extracted human single-rooted teeth were instrumented using the crown-down technique with the Mtwo rotary file system to file 25/6. The teeth were randomly divided into five experimental groups (n = 15); Group 1 obturated with AH plus, Group 2 obturated with MTA BIOSEAL, Group 3 obturated with Endoseal, Group 4 positive control (POS CTRL) root canals are processed but not obturated, and negative control- apex of teeth completely covered with nail varnish, canals are not treated or obturated. In the first three groups, the single cone obturation technique with gutta-percha 25/6 was used. Apical microleakage was assessed with the dye extraction method, where the absorbance of 2% methylene blue was measured using a spectrophotometer. Results: The mean dye concentration values were MTA 22.79, AH plus 31.16, Endoseal 36.67, POS CTRL 280.15, negative control 9.01. Analysis of variance and pairwise comparisons indicated a significant difference in apical microleakage between the investigated groups (F = 3448, p < 0.001). The MTA BIOSEAL showed significantly less apical microleakage than the AH plus and Endoseal. The AH plus showed less apical microleakage than the Endoseal, although there was no significant difference between these two sealers. Conclusion: With the limitation of the study, it was concluded that MTA sealers show statistically less apical leakage than AH Plus and Endoseal.

(1) Background: This study investigates the effects of curing light intensity, exposure time, and distance on the Vickers microhardness (VMH), hardness bottom-to-top ratio (HR), and temperature rise (TR) of conventional dental resin-based composite (RBC). (2) Materials and Methods: Specimens of one conventional RBC (Tetric EvoCeram, Ivoclar Vivadent) were cured with 12 different curing protocols (CPs), created with three different light intensities (Quartz Tungsten Halogen 300 mW/cm², LED 650 mW/cm², LED 1100 mW/cm²), two exposure times (20 and 40 s), and two distances of curing tip (0 and 8 mm). The VMH of top (VMH-T) and bottom (VMH-B) surfaces was measured. The hardness bottom-to-top ratio (HR) was calculated from VMH-B and VMH-T. The HR below 80% was rated as inadequate polymerization. The TR at the depth of 2 mm within the RBC was measured using a K-type thermocouple. Data were analyzed using Levene’s test and the multivariate analysis of variance (MANOVA). The level of significance was set at p < 0.05. (3) Results: Exposure time and distance significantly influenced VMH-B and HR. Increased distance significantly reduced VMH-B, HR, and TR. CPs 300 mW/cm²/8 mm/20 s and 650 mW/cm²/8 mm/20 s produced inadequate polymerization (HR < 80%). Prolonged exposure time produced higher values of VMH-B and HR. The TR was significantly influenced by light intensity and distance. (4) Conclusions: Suboptimal light intensity (2) can produce inadequate polymerization at the lower side of the composite layer when used from a distance. Prolonged irradiation can improve the polymerization to a certain extent. Clinicians are advised to monitor the intensity of the LCUs in order to optimize the photopolymerization process. Caution is required when polymerizing with high-intensity curing light in direct contact with the RBC with longer exposure times than recommended.

Objective This study investigated biomechanical behavior of custom post core made of six different materials on the tooth with and without the ferrule under different occlusal load. Materials and Methods Three-dimensional models of mandibular first premolar, with and without ferrule, reconstructed from micro-computed tomography image are restored with different custom post core and zirconia crowns. By using the finite element analysis, von Mises stress shown in MPa was measured under simulated axial and oblique load of 200 [N]. To compare the stress distribution, six different custom post core materials were chosen: zirconia, Ni-Cr alloy, gold alloy, glass fiber-polyether ether ketone, polyether ether ketone, and carbon fiber-polyether ether ketone. Results Custom post cores with a higher modulus of elasticity showed higher measured stress in the posts, but less stress in dentin. Measured stress in custom post core under oblique loading was approximately three times higher compared with axial loading. Stress in custom post core and in dentin under both types of loads was slightly higher in teeth without ferrule effect. Conclusion The use of custom cast post cores made of different alloys is recommended in restoration of endodontically treated teeth, with extensive loss of tooth structure especially in teeth without ferrule effect.

(1) Background: This study evaluates the effect of a conventional/low-voltage light-curing protocol (LV protocol) (10 s with 1340 mW/cm²) and high-voltage light-curing protocol (HV protocol) (3 s with 3440 mW/cm²) on the microhardness (MH) of dental resin-based composites (RBCs). Five resin composites were tested: conventional Evetric (EVT), Tetric Prime (TP), Tetric Evo Flow (TEF), bulk-fill Tetric Power Fill (PFL), and Tetric Power Flow (PFW). (2) Materials and Methods: Two tested composites (PFW and PFL) were designed for high-intensity light curing. The samples were made in the laboratory in specially designed cylindrical molds; diameter = 6 mm and height = 2 or 4 mm, depending on the type of composite. Initial MH was measured on the top and bottom surfaces of composite specimens 24 h after light curing using a digital microhardness tester (QNESS 60 M EVO, ATM Qness GmbH, Mammelzen, Germany). The correlation between the filler content (wt%, vol%) and the MH of the RBCs was tested. For the calculation of depth-dependent curing effectiveness, the bottom/top ratio for initial MH was used. (3) Conclusions: MH of RBCs is more dependent on material composition than on light-curing protocol. Filler wt% has a greater influence on MH values compared to filler vol%. The bottom/top ratio showed values over 80% for bulk composites, while for conventional sculptable composites, borderline or suboptimal values were measured for both curing protocols.

The aim of this study was to compare time of preparation and canal aberrations in a simulated root canals after using three different rotary systems: Endostar E5, Endostar E3 and T One File Gold. A total of 90 endodontic training blocks were used in this study and divided into three groups consisting of 30 each (n = 30). Blocks processing was performed by thirty dentists without any prior experience in rotary instrumentation techniques. In the first group blocks were prepared using Endostar E5, in second one with Endostar E3 and in third one with T One File Gold system. The preparation time was measured. The postoperative image of each block was taken by stereomicroscope and canal aberrations (ledge and instrument fracture) was recorded. Statistical analysis was done by SPSS software. Instrumentation with T One File Gold system is significantly faster compared to instrumentation with Endostar E5 and Endostar E3 systems (p <0.05). There are no statistically significant differences in the type and number of procedural errors between Endostar E5, Endostar E3 and T One File Gold systems when the operators have no previous experience in rotary instrumentation techniques. Under the conditions of this study, the incidence of examined canal aberrations were similar for all tested systems. The preparation time was significantly shorter with single file system.

Objective: The present study aims to investigate the influence of presence and shape of cervical lesions on biomechanical behavior of mandibular first premolar, subjected to two types of occlusal loading using three-dimensional (3D) finite element method (FEM). Materials and Methods: 3D models of the mandibular premolar are created from a micro computed tomography X-ray image: model of sound mandibular premolar, model with the wedge-shaped cervical lesion (V lesion), and model with saucer-shaped cervical lesion (U lesion). By FEM, straining of the tooth tissues under functional and nonfunctional occlusal loading of 200 (N) is analyzed. For the analysis, the following software was used: CTAn program 1.10 and ANSYS Workbench (version 14.0). The results are presented in von Mises stress. Results: Values of calculated stress in all tooth structures are higher under nonfunctional occlusal loading, while the functional loading is resulted in homogeneous stress distribution. Nonfunctional load in the cervical area of sound tooth model as well as in the sub-superficial layer of the enamel resulted with a significant stress (over 50 [MPa]). The highest stress concentration on models with lesions is noticed on the apex of the V-shaped lesion, while stress in saucer U lesion is significantly lower and distributed over wider area. Conclusion: The type of the occlusal teeth loading has the biggest influence on cervical stress intensity. Geometric shape of the existing lesion is very important in the distribution of internal stress. Compared to the U-shaped lesions, V-shaped lesions show significantly higher stress concentrations under load. Exposure to stress would lead to its progression.