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Öğe Ana modelin elde edilmesinde vakumlu kabin tekniği(2015) Akpınar, Yusuf Ziya; Aslan, Muhammed Ali; Tatar, Numan; Yılmaz, BetülAmaç: Bu çalışmanın amacı farklı karıştırma ve döküm tekniklerinin alçının fiziksel özellikleri üzerine etkisini karşılaştırmaktır. Gereç ve Yöntemler: Çalışma planı iki yönlü olarak düzenlenmiştir; farklı karıştırma tekniklerinin alçının fiziksel özellikleri ve kalitesi üzerine etkisini incelemek. Örnekler karıştırma tekniklerine göre dört gruba ayrıldı: El ile karıştırma (Grup H), vakumlu mikser ile karıştırma (Grup VM), vakumlu kabin ile karıştırma (Grup VK), vakumlu mikser ve sonrasında vakumlu kabin kombinasyonu(Grup VM/VK) . Altmış örnek, üç nokta bükülme testi için hazırlandı. Model kırıklıkları kaydedilerek Kruskal-Wallis istatistik testi ile analiz edildi. Alt çene fantom akrilik dişler (Diş No: 43, 42, 41, 31, 32, 33) shoulder basamaklı metal desteksiz seramik veneer kron preparasyonu yapıldı ve ölçü alındı. Ana model üzerindeki poroziteler x40 büyütmeli mikroskop altında incelendi. Sonuçlar analizi için Tek Yönlü Varyans Analiz (α = 0.05) yöntemi kullanıldı. Bulgular: Sonuçlar göster, VM/VK tekniğinin modeldeki poroziteyi anlamlı ölçüde (p < 0.05) azalttığını ve modelin dayanım derecesini arttırdığını göstermiştir. En yüksek dayanım değeri Grup VM/VK' da (31.8 ± 0.7 MPa) oluşurken en az dayanım değeri Grup H' de (20.8 ± 0.1 MPa) oluştu. Sonuç: Vakumlu kabin ve vakumlu mikser tekniği ile kombinasyonu ana model dayanıklılığını arttırır ve poroziteyi azaltır. Bundan dolayı bu teknik ana modellerin dökülmesi için düzenli olarak kullanılabilir.Öğe Changing the bonding force of impression tray to edentulous maxillary jaw simulator with impression valve system: in vitro study(Medknow Publications & Media Pvt Ltd, 2015) Akpınar, Yusuf Ziya; Yılmaz, Betül; Tatar, Numan; Demirtağ, ZülfikarObjective: The aim of this study was to evaluate the effect of an impression valve system (IVS) on the bonding force between an impression tray and an edentulous maxillary jaw. Materials and Methods: In this in vitro study, a polyether-coated maxillary jaw simulator (PM) was used to model an edentulous maxillary jaw. The IVS was placed into individual impression trays. An irreversible hydrocolloid impression was taken of the PM when the IVS was open and closed. The impression tray bonding force was measured using a digital dynamometer. Student's t-test was used to determine the significance of the difference between these two groups. Results: The impression tray was more easily separated from the PM when the IVS was open (108 +/- 3.9 N). The separation was more difficult when the IVS was closed (153.7 +/- 14.2 N). The difference between these two findings (P = 0.000) was significant. Conclusion: The use of an IVS facilitates the removal of the impression tray from the mouth when taking impressions from an edentulous maxillary jaw.Öğe The effect of amine-free initiator system and the polymerization type on color stability of resin cements(Nihon Univ, School Dentistry, 2016) Ural, Çağrı; Duran, İbrahim; Tatar, Numan; Öztürk, Özgür; Kaya, İsmailWe investigated the short-term (4 weeks) color stability of light-cure and dual-cure resin cements. Sixty disk-shaped test specimens of adhesive resin cement (10 x 1 mm) were prepared. One feldspathic porcelain test specimen (12 x 14 x 0.8 mm) was prepared from a prefabricated ceramic block. The feldspathic sample was placed on the resin cement disk and all the measurements were performed without cementation. Specific color coordinate differences (Delta L, Delta a, and Delta b), and the total color differences (Delta E) were calculated after immersion in distilled water for different periods. Data were compared using one-way analysis of variance (ANOVA) (alpha = 0.05). The test results revealed that different chemical structures and curing modes affected the Delta E values (P < 0.05). The highest Delta E values were obtained for RelyX Unicem dual-cure cement (2.14 +/- 0.40), and the lowest for NX3 light-cure cement (0.78 +/- 0.34). Third generation adhesive resin cement free of tertiary amines and benzoyl peroxide showed relatively slight color change in both test groups (light-cure and dual cure resin cement).Öğe Effect of bleaching agents on surface texture of feldspathic ceramic(Ondokuz Mayis Universitesi, 2014) Ural, Çağrı; Gençer, Yücel; Tarakçı, Mehmet; Aslan, Muhammed Ali; Arıcı, Selim; Tatar, NumanThe aims of this study were to evaluate the effects of different carbamide peroxide concentrations on surface structure changes of porcelain restorative materials. A total of 50 discs were made and divided into five groups each include 10 specimens. One group served as control and no bleaching agent was applied. Other groups were immersed in the bleaching gels with the concentration of 10% (Group 10), 15% (Group 15), 20% (Group 20), 35% (Group 35) for an average of 8 hours per day. The bleaching procedure was performed over a period of 21 days. The surface roughness values were measured by surface profilometry. Treated ceramic surfaces were examined by scaning electron microscopy (SEM) and atomic force microscopy (AFM). The data were analyzed by analysis of variance and post-hoc Tukey test. The results showed that higher concentration of carbamide peroxide gel effect the surface roughness of test specimens significantly. The highest surface roughness values were obtained in group 35 (0.57 ?m±0.19) and showed significantly different from group C (0.24 ?m±0.11) which was the lowest surface roughness values. The concentration of the carbamide peroxide bleaching agent used in this study affected the surface roughness of the porcelain test specimens. Ceramic restoration should be protected before any bleaching for preventing negative effects of agent on surface properties.Öğe Effect of impression valve system on adhesion force of impression materials to edentulous maxillary jaw : a preliminary clinical study(Taylor & Francis Ltd, 2015) Akpınar, Yusuf Ziya; Uzun, İsmail Hakkı; Yılmaz, Betül; 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 Repair Success of Two Innovative Hybrid Materials as a Function of Different Surface Treatments(Quintessence Publishing Co Inc, 2018) Tatar, Numan; Ural, ÇağrıPurpose: To evaluate surface treatments for chipping in order to avoid bonding problems between hybrid materials and composite resin and to determine the optimal surface treatment method during intraoral repair of restorations to achieve clinical success. Materials and Methods: A total of 96 samples were prepared from computer-aided design/computerassisted manufactured (CAD/CAM) blocks: 48 polymer-infiltrated ceramic (PIC) and 48 resin nano-ceramic (RNC). Prior to application of the surface treatments, the two test groups were each divided into four subgroups: control group; hydrofluoric acid group; hydrofluoric acid with silane group; and air-abraded with silica-coated aluminum oxide (Al2O3) sand with silane group. Each subgroup contained 12 samples. A shear bond strength (SBS) test was performed after artificial aging (5,000 cycles, 5 degrees C to 55 degrees C). Results: For both types of ceramic used, all subgroups showed significantly higher SBS values than the control groups (P < .05). The highest SBS values for both types of ceramic were observed in the air-abraded with silica-coated Al2O3 particles group. Conclusion: Each of the surface treatment methods increased the SBS, with the most effective method being air abrasion with silica-coated Al2O3. Int J Prosthodont 2018;31:267-270.Öğe RESTORATION OF PRIMARY TEETH WITH THE IPS e.max IN THE ABSENCE OF CONGENITAL MANDIBULAR CENTRAL TEETH: A 3-YEAR CASE REPORT(2015) Akpınar, Yusuf Ziya; Yılmaz, Betül; Tatar, NumanHipodonti, bir yada daha fazla daimi dişin konjenital eksikliği olarak tarif edilir. Bu vakalar için değişik tedavi seçenekleri tanımlanmıştır; süt dişinin çekimi ve dişsiz sahanın sabit ya da implant destekli diş protezi ile restorasyonu ve ortodontik tedavi. Konjenital daimi mandibular santral kesici dişlerinin eksikliğinden dolayı estetik olmayan görüntüsünden şikâyetçi olan 26 yaşında bir bayan hasta, diş tedavisi için başvurmuştur. Mevcut olan mandibular süt santral dişleri, diş çekimi yapılmadan iki üyeli lityum disilikat esaslı sabit bölümlü protez kullanılarak restore edilmiştir.
