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Öğe Adhesion of veneering composite to metal-free CAD/CAM materials: effect of surface conditioning and adhesive resin type(Taylor & Francis Ltd, 2023) Onugoren, Nazik Irem; Demirci, Fatih; Tatar, Numan; Eyuboglu, Tan Firat; Ozcan, MutluObjectivesThis study aimed to investigate the adhesion of veneering composite to metal-free computer-aided design/computer-aided manufacturing (CAD/CAM) materials with different compositions after surface conditioning and application of adhesive resins.Materials and MethodsA total of one hundred and sixty specimens were divided into four groups (n = 40) manufactured either from polyetheretherketone (PEEK; KERAstar PEEK), polyetherketoneketone (PEKK; Pekkton), fiber-reinforced composite (FRC; Trinia), or high-impact polymer composite (COMP; Bredent HIPC) CAD/CAM discs. Each group was then randomly subdivided into four different subgroups of adhesive systems (n = 10) as Visiolink (Bredent), Single Bond Universal (3M), G-Premio BOND (GC), and OptiBond Universal (Kerr). The shear bond strength (SBS) of each specimen with veneering composite material was tested with a universal testing machine following thermocycle aging (5000 times). The modes of failure resulting from the tests were determined with scanning electron microscope (SEM), dispersive spectroscopy (EDS), and analytical imaging. The data were statistically analyzed with two-way ANOVA and Bonferroni post hoc tests (alpha = 0.05).ResultsThe highest SBS values among all groups were found for the COMP material (20.28 +/- 2.08 MPa) with OptiBond Universal adhesive, while the lowest for the PEEK material (10.33 +/- 2.47 MPa) with G-Premio BOND. The most common failure mode for the PEEK and PEKK specimens was adhesive failure, for the FRC and COMP groups mixed failures were common.ConclusionsBond strength values of at least 10 MPa were achieved for all tested between metal-free CAD/CAM materials and adhesive resin application.Öğe Comparison of the push‑out bond strength of different prefabricated fiber post systems: An in vitro study(Wolters Kluwer Medknow Publications, 2023) Karabaş, Ayşe; Avcu, Güler Yildirim; Tatar, NumanIntroduction: The aim of the current study was to evaluate the effects of post type and hydrothermal aging on the push-out bond strength of four different fiber post systems. Materials and Methods: Eighty extracted human upper central incisors were treated with root canal treatment and divided into four different groups according to the treated post system (UniCore post [group U] [n = 20], Reforpost fiber [group R] [n = 20], Voco Rebilda post GT [group V] [n = 20], and EverStick post [group E] [n = 20]). The posts of teeth in all groups were divided into three parts from coronal, middle, and apical aspects. Half of the samples in all groups were subjected to hydrothermal aging (10,000 cycles). All subjects were applied to the crosshead speed push-out bond strength test at a 1-mm/min rate until being fractured. Fracture types were determined with a stereomicroscope. Data were analyzed by Kruskal–Wallis and Chi-square tests statistically. Results: Bond strength values of EverStick post were significantly lower compared to the other groups (P < 0.01). In the presence/absence of hydrothermal aging, push-out bond strength in the coronal and middle regions was significantly higher compared to the apical region in all groups (P < 0.01). Bond strength values decreased in all groups following hydrothermal aging (P < 0.01). Conclusions: Push-out bond strength may be affected more negatively from coronal and middle of the tooth compared to its apical part. Hydrothermal aging may worsen the bond strength. The use of Reforpost fiber, VocoRebilda post GT, and UniCore posts may provide better bond strength compared to EverStick post. © 2023 Saudi Endodontic Journal | Published by Wolters Kluwer - Medknow.Öğe Effect of impression valve system on adhesion force of impression materials to edentulous maxillary jaw: a preliminary clinical study(Taylor & Francis Ltd, 2015) Akpinar, Yusuf Ziya; Uzun, Ismail Hakki; Yilmaz, Betul; Tatar, NumanObjective: The purpose of this preliminary clinical study was to evaluate the effect of novel impression valve system (IVS) on adhesion force of different impression materials to edentulous maxilla. Background data: Impression materials and techniques have an important role in complete denture success. During the functional impression with an individual impression tray (IIT), high adhesive forces exist between edentulous ridge and impression material. Removing the IIT from the mouth with minimal force provides the most accurate and non-deformed impression. Materials and methods: This study included twenty maxillary edentulous patients (n = 20). Patients who had palatal torus, anatomic undercut, gagging reflex, and flabby ridges were excluded from the study. The age range of the participants was 55-70. All patients gave written informed consent. Two impression materials - zinc oxide eugenol (ZOE) and alginate - were used as experimental material. The digital dynamometer was used to determine the adhesion force of impression materials with and without IVS to edentulous maxilla. The mean values of the adhesion forces were analyzed using the Wilcoxon signed-ranks test (alpha = 0.05). Results: The effect of IVS on adhesion force was found to be statistically significant (p<0.05). There were also statistical differences between the ZOE and alginate groups (p<0.05). Conclusions: The IVS is useful to remove the functional impression from the mouth without any deformation and detaching in cases which high adhesive force occurs.Öğe Evaluation of anatomy courses in the faculty of dentistry in line with the views of academic staff and exam performance of students(2020) Canbolat, Mustafa; Tatar, NumanAbstract: Aim: Basic medical sciences have an important place in the curriculum of faculties of dentistry, just as in all fields of science dealing with health. One of these is anatomy. In the Faculty of Dentistry at İnönü University, anatomy course is taught in parallel with the Faculty of Medicine. The aim of this study is to compare the exam performances of medical faculty and dentistry faculty students since the curriculum of anatomy course at İnönü University is taught by the same faculty members and also to learn the attitudes of instructors at the faculty of dentistry through a questionnaire. Material and Methods: First, we compared the success rates of faculty of medicine and faculty of dentistry second year students in their anatomy practice exams during the academic years 2016-2017, 2017-2018 and 2018-2019. After, we conducted a study in which we asked the students to define anatomic structures on radiological images at the end of the academic year 2018-2019 when anatomy courses ended in both faculties. In the final stage of the study, we conducted a questionnaire for the instructors to get their opinions about the anatomy courses they received during their undergraduate education. Results: In all but one of the end of the board exams which were conducted during the three academic years, the success percentage of dentistry faculty students were found to be lower than those of medical faculty students. In the study in which we asked about the anatomic structures through radiological images, the number of the correct answers given by dentistry faculty students was lower than the number of correct answers given by medical faculty students. We believe that the success rate of dentistry faculty students were low since they lost their interest in the course because they were learning information they thought they would not need all their lives long. 73.91% of the instructors think that they received anatomy education more than they needed for their profession, which supports our opinion. Conclusion: We believe that it is wrong to follow the exact medical faculty curriculum in dentistry faculty for anatomy course.Öğe Impact of sars-COV-2 on the attitudes of patients with prosthodontic needs(Bayrakol Medical Publisher, 2022) Tatar, Numan; Karabas, AyseAim: SARS-CoV-2 has caused a global pandemic that has negative consequences for many parts of life. To our knowledge, no study has assessed the effect of the SARS-CoV-2 pandemic on a possible delay in prosthodontic treatments because of a potential concern of contamination in individuals. Therefore, the purpose of this study was to assess this potential impact of fear, as well as oral health-related quality of life, in partially edentulous patients using questionnaires during the SARS-CoV-2 pandemic. Material and Methods: A total of 135 partially edentulous patients (74 females and 61 males aged 18-70 years) participated in this study. A complete questionnaire consisting of general knowledge questions on SARS-CoV-2 and the OIDP scale, which evaluates the effect of oral status on daily activities were used in participants. Results: Statistical analyzes showed that participants with a history of SARS-CoV-2 and/or who are aware of a member of their social circle with a history of the virus, and/or who is deceased, were unwilling to receive dental care during the pandemic. Most of the participants between the ages of 31 and 60 were more worried about the transmission of SARS-CoV -2 during dental treatment. Discussion: Concerns about SARS-CoV -2 contamination of patients over 30 years of age may have a negative impact on oral health due to delayed prosthodontic treatments.Öğe Investigation of the Bond Stregth Between Resin Cement and Current CAD/CAM Restorative Materials Applied With Different Surface Treatments(Inonu University, 2023) Tatar, NumanIn dentistry, the fact that the restorations applied to the patient remain in the patient's mouth for a long time without falling is among the important criteria for the success of the restoration. For this reason, the aim of our study is to examine the relationship between the resin cement and the different surface treatments applied to the current CAD/CAM blocks, which can be polished by the physician without the need for the firing process. 15 samples (n=15) of 2 mm thickness were produced from Vita Enamic (V) Lava Ultimate (L) and PEEK (P) blocks with surface treatments of control (VC, LC, PC), HF acid (VHF, LHF, PHF), 50 µm Al2O3 powder (VAl, LAl, PAl), 30 µm Silica coated Al2O3 powder (VSi, LSi, PSi). The resin cement applied samples were aged by thermal cycling. Afterwards, shear bond strength test was applied to the samples with an universal test device. Bond strength results were evaluated in the statistical program. When the findings were examined, it was seen that all applied surface treatments increased the bonding values.The highest bond strength values in all groups were observed in the silica coated Al2O3 powder (VSi 17.2750±1.89167; LSi 18.0815±1.66664; PSi 14.8151±1.57730). The bond strength values of HF acid applied to Lava Ultimate and Vita Enamic groups were found to be statistically higher than the HF acid group applied to PEEK (p˂0.05). As a result of our study, it has been observed that all surface treatments applied to CAD/CAM blocks increase the bond strength values, and the most successful bond strength value was in the sandblasting surface treatment with silica coated Al2O3 powder. © 2023, Inonu University. All rights reserved.Öğe Investigation of the Lattice Production of Removable Dental Prostheses with CoCr Alloy Using Additive Manufacturing(Springer, 2021) Tatar, Numan; Tuzlah, Mesut; Bahce, ErkanRemovable dentures (RDs) are mostly used to replace missing teeth, increase patients' oral function, esthetic, and phonetics, and restore lost residual ridge, for the maintenance of oral health. The main reasons often preferred for RDs are a cleaning, cost-effective manner, and popular treatment option for edentulous or partially edentulous patients. Unfortunately, the fracture of RDs is a common complication which occurs frequently as a result of fatigue failure by strong masticatory forces and also accidental damage. This causes concerns for patients in terms of stress, cost, and embarrassment. Therefore, a variable number of approaches to prevent the incidence of fracture have been used including the strengthening of acrylic resin and reinforcing the base of dentures. To enhance the fracture resistance and dimensional stability, metal bases and frameworks have been frequently incorporated into the dentures. However, the design of these frameworks is challenging and so requires experience for minimizing potential inaccuracy. In the current study, considering the developments in additive manufacturing technology, metal bases and frameworks were produced in lattice according to nine different unit cell models, compared with the traditional method by destructive and non-destructive experiments. According to the current data, vertical struts in lattice structures are significant in terms of tensile strength. Thus, it is important to choose the unit cell to be used for metal bases and frameworks in RDs. In addition, pores did not have a significant effect on tension resistance, but micro-cracks had a significant effect on lattice structures. The RDs produced with body diagonals with nodes from lattice structures resulted in an average of 160% more resistance to stretching than the RDs produced by the traditional casting method, in a similar density.Öğe New type of infrastucture in fixed prostheses: lattice framework(Springernature, 2025) Tatar, Numan; Bahce, ErkanMetal-supported ceramic restorations have been utilized effectively in fixed prosthetic restorations for many years. However, difficulties like as fractures in the infrastructure and/or superstructure, cracks or ruptures in the superstructure, and failure to completely satisfy the aesthetic expectations are experienced over time in these prostheses, which are commonly made by the casting process. As a result of this, intensive research is being conducted on both the development of infrastructure materials and the development of manufacturing techniques. The effect of the macro/micro bond strength between metal and ceramic was investigated in this research if the metal substructure of the fixed prosthesis is manufactured as a lattice structure rather than a solid using additive manufacturing. The infrastructure was produced in the study as a full-mass and lattice cylindrical structure with a diameter of 1 mm and a length of 1 mm. Following the formation of the lattice structure as diamond and octet-truss structures, ceramic coatings were applied in compliance with clinical application requirements. The samples were compressed to analyze their mechanical characteristics. After the test, the diamond lattice structure, full-mass, and octet-truss lattice structures showing progressively lower toughness. The results were statistically evaluated, with averages of 243.4775, 225.655, and 192.74 for diamond, solid, and octet-truss structures, respectively. The Shapiro-Wilk normality test was performed on each structure, and all structures are appropriate for normal distribution because they had Sig > 0.05 values. Finite element analysis was used to validate the obtained results. The experiment found that the lattice structure is more advantageous in the direction of ceramic coating because it enhances impact absorption energy and the resistance of the ceramic layer to cracking.
