Hungarian Journal of Dentistry 2023-01-11T21:02:50+00:00 Dr. Hermann Péter Open Journal Systems Comparing Fracture Resistance of Monolithic Zirconia Crowns Designed with three Different Thicknesses: An In Vitro Study 2023-01-11T21:01:09+00:00 Safa M. Alzoubi Abdel Ghani Alsahhar Ebtisam Alsalameh <p>A limited available inter-occlusal space has always been a challenge for many dental practitioners, which hinders<br>acquiring aesthetic restorations while conserving the remaining dental structure.<br>This research aims to analyze the relationship between the occlusal thickness of second-generation CAD/CAM<br>monolithic zirconia restorations, and their fracture resistance, in order to determine the feasibility of reducing the occlusal<br>thickness – particularly in the posterior oral area, where a limited inter-occlusal space is usually available, and high biting<br>forces are usually applied.<br>Thirty monolithic zirconia crowns were made using second generation zirconia block with different design settings<br>that divided them into 3 groups (n = 10) according to the occlusal thickness of the restorations: Group A: 2 mm, Group B:<br>1.5 mm, Group C: 1 mm.<br>Thirty designed crowns were cemented to extracted prepared natural upper premolars using glass ionomer cement,<br>then they were tested.<br>Fracture resistance of the monolithic zirconia crowns was significantly influenced by the occlusal thickness, the resistance<br>improved steadily as the thickness increased.<br>Nevertheless, the occlusal thickness could be reduced down to 1 mm and the monolithic zirconia restoration would<br>still own sufficient resistance to tolerate the maximum natural human biting loads of the posterior oral regions.</p> 2022-12-19T00:00:00+00:00 Copyright (c) 2022 Authors Polymerization shrinkage-stress of short fiber-reinforced composite 2022-12-22T12:33:05+00:00 Viktória Néma Tekla Sáry Lili Fanni Szántó Gábor Braunitzer Márk Fráter <p>Background: Polymerization shrinkage-related stress of dental composite materials is a clinically relevant problem. In<br>the presence of proper adhesion, shrinkage produces stress in the remaining tooth structure. The greater the destruction,<br>the less the tooth structure is available to withstand the stress; thus, causing cracks in the enamel. The purpose of<br>this in vitro study was to investigate the number of cracks caused by polymerization shrinkage using two different filling<br>techniques utilising short fibre-reinforced composite (SFRC).<br>Materials and methods: 40 extracted wisdom teeth, prepared with standardized MOD cavity (5 mm deep and 2,5 mm<br>wall thickness) were used. After adhesive treatment, teeth were divided into two groups, each restored with SFRC as<br>follows: Group 1: Bulk-fill technique; Group 2 oblique layering technique (with 2 mm increments). In all specimens, the<br>SFRC was covered<br>with 1 mm packable composite resin. After completion of the restoration, the enamel was examined<br>using a D-Light Pro lamp, and the cracks were documented. In addition, the number of the cracks was further documented<br>after 1 week period.<br>Results: There was no significant difference between the groups in respect of the cracks’ number. After 1 week, the<br>average number in group 1 was 4.95 showing 340% increase, and in Group 2: 4.30 showing the same 340% increase,<br>which significantly differs to the previously obtained values (p = 0.000). There is no significant difference between the<br>techniques regarding total sum of cracks after 1 week.<br>Conclusions: In both techniques, almost an equal number of cracks is developing. During the post-polymerization<br>period, the number of cracks grows significantly irrespective of the chosen technique.</p> 2022-12-19T00:00:00+00:00 Copyright (c) 2022 Authors Synthesis, scanning electron microscopy (SEM) and biocompatibility study of SLA 3D printable biopolymer hydrogel 2023-01-11T21:02:50+00:00 József Bakó Ferenc Tóth Loránd Csámer Lajos Daróczi Csaba Hegedűs <p>Purpose: The demonstration of the production, SEM investigation and study of the biocompatibility of a biopolymerbased<br>3D printed hydrogel.<br>Materials and methods: Hydrogel samples with 1 and 2 mm thickness were planned by Ansys SpaceClaim (Ansys Inc,<br>USA) 3D modeling software. The biodegradable methacrylated-poly-γ-glutamic-acid (MPGA) polymer-based hydrogel<br>were produced by a stereolithographic (SLA) type Formlabs Form 2 (Formlabs Inc.) 3D printer. The surface and structure<br>of the hydrogels were studied by stereo and scanning electron microscopy (SEM) respectively. The biocompatibility<br>of the 3D printed samples was investigated by Alamar blue viability test using MG63 cells. The actual cells growing on<br>the surface of the samples were also examined by SEM.<br>Results: Our results showed that the MPGA based hydrogels were 3D printable by SLA technique. The printed<br>hydrogels are constructed by few hundred diameter nanofibers and web-like structures. The Alamar blue test showed<br>that, however, after 1 day of seeding, the numbers of the MG63 cells were significantly reduced at the hydrogel surface,<br>after another 3 days we could not detect any alteration in the cell number compared to that of the control. Additionally,<br>the SEM examination demonstrated the attachment of the cells to the surface of the hydrogel samples.<br>Conclusions: Our MPGA based polymer system were 3D printable by SLA technique. The prepared nanostructured<br>and biocompatible hydrogels might be promising vehicles for biologically active components in tissue engineering.</p> 2022-12-19T00:00:00+00:00 Copyright (c) 2022 Authors Dental caries prevalence and trends in children - Pathfinder surveys in Hungary over 30 years 2022-12-22T12:33:04+00:00 Judit Szőke Poul Erik Petersen <p>Purpose: Whilst improved oral health in children is noted in most Western countries, it coincides with a high prevalance<br>of oral disease in several countries of Central and Eastern Europe. The purpose of this project is to describe the current<br>level of dental caries in Hungarian children between 5–6 and 12 years and to assess the long-term trends in dental<br>caries in the past 30 years.<br>Methods: A representative survey was undertaken in 2017 It was performed in accordance with the WHO Pathfinder<br>methodology, which also was applied in previous national oral health surveys of 1985, 1991, 1996, 2001, 2008, and 2013.<br>Children of 5–6 and 12 years of age were sampled systematically in all surveys over 30 years period. Relevant data were<br>gathered through visual clinical examinations.<br>Results: In 2017, 43,8% of 5–6 year-olds were free of dental caries, meanwhile, the percentage was lower in rural (34,6%)<br>compared with urban (49,9%) settings. In 2017, approximately 3,5 primary teeth were affected by dental caries among<br>children aged 5–6 years. Most of the incidents consisted of untreated caries. Dental caries occurrence was relatively<br>higher for children living in rural areas. At the age of 12, approximately two permanent teeth suffered from dental caries,<br>and the D-component of the caries index was high. In 1985, 12-year-olds had, on average, 5 teeth affected by the dental<br>caries, and after 30 years, in 2017, the level of caries declined to 2,3 DMFT In 1985, 7,5% of children were caries-free,<br>and the figure grew to 44,7% in 2017. The value of SIC index is 8,43 in 5/6 year olds, and 5,23 in 12-year-olds.<br>Conclusions: By the year 2000, whilst accomplishing WHO’s global goals for oral health of 12-year-olds, Hungary has<br>not yet manage to achieve such goals for the 5-6 year-olds group and has not succeeded in achieving much stricter European<br>ones. It was considered unrealistic for the country to achieve WHO’s goal for 12-year-olds by the year 2020. To<br>achieve an improvement of the child’s oral health, strong emphasis should be given to population-directed oral disease<br>prevention, which includes reduction of sugars consumption, improved oral hygiene, and implementation of public health<br>programs for effective use of fluoride and revitalization of school dentistry.</p> 2022-12-19T00:00:00+00:00 Copyright (c) 2022 Authors The role of the PRF in Oral and Maxillofacial Surgery 2022-12-22T12:33:03+00:00 Martin Major Bálint Trimmel Melinda Polyák Dávid Kovács György Szabó <p>The method for the production of PRF (Platelet Rich Fibrin) was developed in 2000 and belongs to the second generation<br>of platelet concentrates. Several clinical studies have demonstrated its effectiveness in combination with various bone<br>substitutes. The concentrate is prepared by centrifuging the patient's own blood without addition of anticoagulants, and<br>according to the established protocol. The process yields a fibrin-rich clot of leukocytes and platelets that serves as an<br>extracellular matrix. The growth factors from white blood cells and platelets are released slowly (2–3 weeks), and thus,<br>have a beneficial effect on the wound healing. In this article, the authors present their review of the data available in the<br>main literature and report on potential applications of PRF in dental, dentoalveolar, and maxillofacial surgeries (implantology,<br>bone grafting, dentoalveolar surgery, periodontology, sinus closure, sinus elevation, osteonecrosis, endodontics).</p> 2022-12-19T00:00:00+00:00 Copyright (c) 2022 Authors