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    Detection of microcalcification in digitized mammograms with multistable cellular neural networks using a new image enhancement method: automated lesion intensity enhancer (ALIE)
    (Tubitak Scientific & Technological Research Council Turkey, 2015) Civcik, Levent; Yilmaz, Burak; Ozbay, Yuksel; Emlik, Ganime Dilek
    Microcalcification detection is a very important issue in early diagnosis of breast cancer. Generally physicians use mammogram images for this task; however, sometimes analyzing these images become a hard task because of problems in images such as high brightness values, dense tissues, noise, and insufficient contrast level. In this paper, we present a novel technique for the task of microcalcification detection. This technique consists of three steps. The first step is focused on removing pectoral muscle and unnecessary parts from the mammogram images by using cellular neural networks (CNNs), which makes this a novel process. In the second step, we present a novel image enhancement technique focused on enhancing lesion intensities called the automated lesion intensity enhancer (ALIE). In the third step, we use a special CNN structure, named multistable CNNs. After applying the combination of these methods on the MIAS database, we achieve 82.0% accuracy, 90.9% sensitivity, and 52.2% specificity values.
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    Digitalization and Urological Diseases: Severity of Cyberchondria and Level of Health Anxiety in Patients Visiting Outpatient Urology Clinics
    (Mary Ann Liebert, Inc, 2023) Ozkent, Mehmet Serkan; Kilinc, Muzaffer Tansel; Hamarat, Mustafa Bilal; Yilmaz, Burak; Goger, Yunus Emre; Ozkent, Yasemin; Piskin, Mehmet Mesut
    This study aimed to evaluate the cyberchondria levels of patients who applied to the urology outpatient clinic. The second goal of this study was to evaluate the relationship between cyberchondria severity and health anxiety in these patients. The present prospective observational study was conducted at the urology outpatient clinic of two tertiary centers in our city between September and December 2021. Eligible patients were the adult patients (>18 and <= 60 years) who used the Internet for health purposes and had no self-reported psychological or mental disease. The patients were divided into following groups according to their complaints: general urology, uro-oncology, andrology, functional urology, and endourology (stone disease). The level of cyberchondria and health anxiety was evaluated for these patients by using the Short Health Anxiety Inventory (SHAI) and a short-form version of the Cyberchondria Severity Scale (CSS-12). This study enrolled 578 patients (190 female, 388 male). The mean age of patients was 43.4 +/- 13.3 years (18-60 years). The mean CSS-12 was 28.1 +/- 12.1, and the mean value of SHAI was 18.9 +/- 13.6. The patients had andrological symptoms, is uniquely related to higher CSS and health anxiety, and followed by uro-oncological diseases. However, the least relationship was observed in patients with functional urological diseases (analysis of variance [ANOVA], p < 0.001 for CSS-12; p < 0.001 for SHAI). In addition, a positive correlation was observed between the CSS and SHAI (Pearson's correlation = 0.782). The increased level of cyberchondria causes increased health anxiety and an increased disease burden in these patients. Therefore, physicians should consider this increased treatment burden during the treatment of patients.
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    Effect of internal connection type and screw channel angle on the screw stability of anterior implant-supported zirconia crowns
    (Wiley, 2023) Cakmak, Guelce; Guven, Mehmet Esad; Donmez, Mustafa Borga; Kahveci, Cigdem; Schimmel, Martin; Abou-Ayash, Samir; Yilmaz, Burak
    ObjectivesTo investigate the effect of implant-abutment connection and screw channel angle on screw stability by comparing a newly introduced and an established connection, before and after cyclic loading.Materials and MethodsImplants (N = 44) with Torcfit (TF) or Crossfit (CF) connection were divided to be restored with a straight (CFS and TFS) or an angled screw access channel (CFA and TFA) titanium-base abutment (n = 11). CFA and TFA received screw-retained crowns, whereas CFS and TFS received hybrid zirconia abutments and cement-retained crowns. The initial torque value (ITV) of each complex (ITVI) and removal torque value (RTV) after 24 h (RTVI) were measured. Screws were replaced with new ones, ITVs were recorded again (ITVF), and crowns were cyclically loaded (2.4 million cycles, 98 N) to measure RTVs again (RTVF). Percentage torque loss was calculated. Data were analyzed (a = 0.05).ResultsITVs were similar among groups (p = .089). CF led to higher RTVs (p = .002), while CFS had higher RTVI than CFA (p = .023). After 24 h, CFS had lower percentage torque loss than TF, while CFA had lower percentage torque loss than TFA (p = .011). After cyclic loading, CF led to lower percentage torque (p < .001).ConclusionThe implant-abutment connection affected the removal torque values. However, no screw loosening occurred during cyclic loading, which indicated a stable connection for all groups. Screw access channel angle did not affect screw stability after cyclic loading.
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    Evaluation of Dimensional Stability and Occlusal Wear of Additively and Subtractively Manufactured Resin-Based Crowns after Thermomechanical Aging
    (Mdpi, 2023) Guven, Mehmet Esad; Cakmak, Gulce; Donmez, Mustafa Borga; Yilmaz, Burak
    The knowledge on the surface deviations and wear of recently introduced additively or subtractively manufactured materials indicated for definitive prosthesis is limited. The aim of this present study was to evaluate the external surface and mesiodistal width deviation and the occlusal surface wear of one additively manufactured composite resin (MS) and three subtractively manufactured resins (nanographene-reinforced polymethylmethacrylate (GR), conventional polymethylmethacrylate (PMMA), and reinforced composite resin (BC)) after thermomechanical aging. Molar-shaped crowns were fabricated in the tested materials and digitized with an intraoral scanner (CEREC Primescan; Dentsply Sirona, Bensheim, Germany). Each crown was subjected to thermomechanical aging and rescanned with the same scanner. A three-dimensional analysis software (Geomagic Control X v.2022.1; 3D Systems, Rock Hill, SC, USA) was used to calculate the deviations on the external surface, mesiodistal width, and wear on the occlusal surfaces of the tested crowns. Data were analyzed using one-way ANOVA and Tukey's tests (alpha = 0.05). MS had higher external surface deviations than PMMA and GR (p <= 0.038) and higher mesiodistal width deviations than PMMA and BC (p = 0.004). BC and GR had higher volume loss than PMMA (p <= 0.002). The additively manufactured composite resin was more prone to deviations, while reinforced composite resin had lower wear resistance than most of the tested materials.
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    A new method for skull stripping in brain MRI using multistable cellular neural networks
    (Springer London Ltd, 2018) Yilmaz, Burak; Durdu, Akif; Emlik, Ganime Dilek
    This study proposes a new method on detecting brain region in MRI data. This task is generally named as skull stripping in the literature. The algorithm is developed by using the cellular neural networks (CNNs) and multistable CNN structures. It also includes a contrast enhancement and noise reduction algorithm. The algorithm is named as multistable cellular neural network on MRI for skull stripping (mCNN-MRI-SS). Three different case studies are performed for measuring the success of the algorithm. Also a fourth case study is performed to evaluate the supporting algorithm, the CEULICA. First two evaluations are performed by using well-known MIDAS-NAMIC and Brainweb databases, which are properly organized Talairach-compatible databases. The third database was obtained from the research and application hospital of Necmettin Erbakan University Meram Faculty of Medicine. These MRI data were not Talairach-compatible and less sampled. The algorithm achieved 0.595 Jaccard, 0.744 Dice, 0.0344 TPF and 0.383 TNF mean values with the Brainweb T1-weighted images and 0.837 Jaccard, 0.898 Dice, 0.0124 TPF and 0.1511 TNF mean values with the MIDAS-NAMIC T2-weighted images. The algorithm achieved 0.8297 Jaccard, 0.9012 Dice, 0.0951 TPF and 0.1225 TNF mean values and achieved with the obtained data the best values among the other algorithms. As a result, it can be claimed that algorithm performs best with the non-Talairach-compatible MRI data due to its nature of performing at cellular level.
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    Trueness and precision of combined healing abutment scan body system scans at different sites of maxilla after multiple repositioning of the scan body
    (Elsevier Sci Ltd, 2023) Donmez, Mustafa Borga; Guven, Mehmet Esad; Yilmaz, Deniz; Abou-Ayash, Samir; Cakmak, Gulce; Yilmaz, Burak
    Objectives: To evaluate the accuracy of the scans of the combined healing abutment-scan body (CHA-SB) system located at different sites of the maxilla when SBs are replaced in between each scan.Methods: Three SBs were seated into HAs located at the central incisor, first premolar, and first molar sites of a maxillary model inside a phantom head, and the model was scanned extraorally (CEREC Primescan SW 5.2). This procedure was repeated with new SBs until a total of 10 scans were performed. Standard tessellation language files of CHA-SBs at each implant location were isolated, transferred into analysis software (Geomagic Control X), and superimposed over the proprietary library files to analyze surface (root mean square), linear, and angular deviations. Trueness and precision were evaluated with one-way analysis of variance and Tukey tests. The correlation between surface and angular deviations was analyzed with Pearson's correlation (alpha=0.05).Results: Molar implant scans had the highest surface and angular deviations (P <=.006), while central incisor implant scans had higher precision (surface deviations) than premolar implant scans (P=.041). Premolar implant scans had higher accuracy than central incisor implant scans on the y-axis (P <=.029). Central incisor implant scans had the highest accuracy on the z-axis (P <=.018). A strong positive correlation was observed between surface and angular deviations (r = 0.864, P<.001).Conclusion: Central incisor implant scans mostly had high accuracy and molar implant scans mostly had lower trueness. SBs were mostly positioned apically; however, the effect of SB replacement can be considered small as measured deviations were similar to those in previous studies and the precision of scans was high.Clinical Significance: Repositioning of scan bodies into healing abutments would be expected to result in similar single crown positioning regardless of the location of the implant, considering high scan precision with the healing abutment-scan body system. The duration of the chairside adjustments of crowns in the posterior maxilla may be longer than those in the anterior region.