Current Science International

Push-out Bond Strength of Resin-based Sealer After Using of Nanochitosan as a Final Irrigant: An In-vitro Study

2026-07-25T03:12:02+00:00

Background: The study aimed to assess the push-out bond strength (PBS) of resin-based sealers following three different endodontic irrigation protocols: group I (2.5% Sodium hypochlorite (NaOCl)+ saline irrigation) as a negative control, group II (2.5% NaOCl + 17%
Ethylenediaminetetraacetic acid (EDTA) irrigation) as positive control, and group III (2.5% NaOCl+0.2% chitosan nanoparticles(CNPs). Materials and Methods: Twenty-four extracted teeth with a single root were prepared using rotary NiTi files set to size 35/.04 and standardized to a root length of 12 mm. Based on the irrigation protocol used, samples were randomly divided into three groups, with eight roots per group. Using the cold lateral compaction technique, gutta-percha and ADSEAL resin-based sealant were inserted into the canals. Universal testing machine was used to evaluate the push-out bond strength of 2-mm-thick specimens taken from the coronal third. The data was examined with the use of Bonferroni's post-hoc test (α=0.05) and one-way ANOVA. Results: Highest mean push-out bond strength was observed in the CNPs group (4.74 ± 0.478 MPa), followed by the EDTA group (4.59 ± 1.551 MPa), ANOVA showed a significant difference among groups (p=0.015). Both CNPs and EDTA groups exhibited significantly higher bond strength than the control (p<0.05), with no significant difference between CNPs and EDTA. Conclusion: Root canal dentine adhered better to resin-based sealers when 0.2% CNPs were added.

Impact of Different Digital Fabrication Techniques of Substructure Materials on Stress Distribution in all-on-4 Mandibular Restorations. A Finite Element Analysis

2026-08-14T12:22:13+00:00

Statement of the problem: All-on-four concept is used as an outstanding choice for edentulous
patients. Framework characteristics of such restoration play a crucial role in its long-term success,
affecting all aspects from biomechanical stability through osseointegration to patient satisfaction.
Study aim: Utilizing finite element analysis (FEA) to investigate the biomechanical performance of
different framework materials with solid conventional geometry and topographically optimized ones,
as a substructure of all-on-four restorations. Materials and methods: A 3D model was created. The
framework materials were Titanium, and Titanium Dioxide- reinforced PEEK (TiO2-PEEK)
fabricated by 3D printing, one conventional, and one with optimized topography. Deformation and
stress were assessed under vertical and oblique loads. Results: No failure occurred in any component.
Titanium absorbed high internal stress with less stress transferred to model components, but TiO2- PEEK underwent minimal internal stress with high stress on the model components. Topology optimization contributed to redistribution of structural stress, mitigating peak stress concentrations at critical cantilever junctions and minimizing excessive deformation. Conclusion: The tested materials
and designs were found to be competent as all-on-four frameworks. Optimized topography offered excellent biomimetic compromise for both selected materials, avoiding the structural stress peaks of rigid metal designs while protecting the peri-implant bone from the excessive strains associated with standard flexible polymers.

A Comparative Evaluation of Sealing Ability and Diametral Tensile Strength of two Pulp Capping Materials “ Sodium Hexa Meta Phosphate SHMP and Mineral Trioxide Aggregate MTA”: An in Vitro Study

2026-08-14T12:31:11+00:00

Background: Indirect pulp capping is a preventative procedure that keeps the pulp alive by sealing the remaining damaged dentin with a bioactive substance. Mineral trioxide aggregate (MTA) is frequently utilised, however, its limitations have prompted the development of alternative materials such as sodium hexametaphosphate (SHMP). Aim of the study: To investigate and compare the sealing ability and diametral tensile strength (DTS) of SHMP and MTA as indirect pulp capping materials. Materials and Methods: Sealing ability was evaluated using methylene blue dye penetration and stereomicroscope in 24 extracted human permanent premolars (n=12/group). DTS was assessed using 20 disc-shaped specimens (n=10/group) with a universal testing machine. Statistical analysis was carried out with the Mann-Whitney U test (p < 0.05). Results: SHMP demonstrated significantly better sealing ability than MTA, with lower dye penetration scores (0.83 ± 1.11 vs. 2.75 ± 0.87; p = 0.0003). SHMP also showed significantly higher DTS than MTA (1.171 ± 0.217 MPa vs. 0.736 ± 0.309 MPa; p = 0.0109). Conclusion: Given the constraints of this in vitro investigation, SHMP exhibited enhanced sealing capability and diametral tensile strength relative to MTA, indicating its potential as an advantageous pulp capping substance.

Evaluation of Water Sorption and Solubility, Fluoride release and Microhardness of One Step Versus Conventionally Placed Glass Ionomer Restorative Material

2026-08-14T12:36:30+00:00

Objectives: This in vitro study compared a one step placed glass ionomer (GI), Ketac Universal Aplicap (KUA), with a conventionally placed GI, Ketac Molar Aplicap (KMA), with and without resin coating, regarding water solubility and solubility, fluoride release, and microhardness. Materials and Methods: A total of 120 samples were prepared, 40 for each test (n=10 per subgroup). Water sorption and solubility were determined according to ISO 4049 after 7 days of immersion. Fluoride release was quantified using calibrated fluoride ion selective electrode at 1 and 7 days. Vickers microhardness was measured under a 50 g load applied for 10 s. Results: coating statistically significantly reduced solubility in both materials (KMA: p = 0.003; KUA: p = 0.001) moreover, water sorption did not differ statistically significantly among the groups. Non coated KMA exhibited statistically significant higher solubility than non coated KUA (165.36 ± 3.110,137.23 ± 4.291 μg/mm³; p = 0.001) respectively, and coating also statistically significantly reduced fluoride release in both materials at 1 and 7 days (p = 0.001); release increased statistically significantly from day 1 to 7 days (p < 0.05), and coated KUA released more fluoride than coated KMA at 7 days (3.47 ± 0.316, 2.89 ± 0.422 ppm; p = 0.039) respectively. Coating statistically significantly improved microhardness only for KUA (p = 0.043). Conclusion: Resin coating improved the stability and microhardness of
both GI but attenuated their fluoride release, and the one step material did not behave equivalently to the conventionally placed material under coating.

Assessing the Epidemiology and Risk Factors of Suicidal Attempts in Children and Adolescents at Assiut University Children’s Hospital

2026-08-14T12:41:18+00:00

Introduction: Suicide attempts among children and adolescents represent a growing public health concern worldwide. Identifying the epidemiological characteristics and associated risk factors for suicidal attempts in this population is essential for developing effective preventive strategies. Materials and Methods: This cross-sectional observational study was conducted at Assiut University Children’s Hospital, Egypt, from January to December 2024, among children and adolescents aged 5– 18 years, of both sexes. Data were collected using a structured questionnaire assessing demographic characteristics, socioeconomic status (SES), and risk factors (child abuse, family factors, schoolrelated stressors, bullying, social isolation, and internet/social media use) related to suicidal attempts. Statistical analysis was performed using SPSS version 24.0. Results: Among 13,509 admissions, 34 suicide attempt cases were identified, yielding an incidence of 2.5 per 1,000 admissions. The mean age was 15.1 ± 1.4 years; 79.4% were females and 67.6% were of low socioeconomic status. Previous suicidal ideation was reported by 73.5% of participants. The major risk factors included internet
addiction (91.2%), poor parent–child communication (88.2%), low parental care (67.6%), social isolation (61.8%), school-related problems and bullying (58.8%), and emotional abuse (50%). The most common method of suicide attempt was aluminum phosphide ingestion (38.2%), which was responsible for all deaths (8.8%) in this study.