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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 Biomechanical and biochemical evaluation of the effect of systemic application of omeprazole on the osseointegration of titanium implants(Springer Japan Kk, 2021) Tekin, Samet; Dundar, Serkan; Demirci, Fatih; Bozoglan, Alihan; Yildirim, Tuba Talo; Gunes, Nedim; Acikan, IzzetBackground This study aimed to investigate the effects of systemic omeprazole treatment on the osseointegration of titanium implants. Material and methods After surgical insertion of titanium implants into the metaphyseal part of rats' both right and left tibial bones, the animals were randomly divided into three equal groups: control (n = 8), omeprazole dosage-1 (n = 8) (OME-1), and omeprazole dosage-2 (n = 8) (OME-2) and totally 48 implants were surgically integrated. The rats in the control group received no treatment during the four-week postoperative experimental period. In the OME-1 and OME-2 groups, the rats received omeprazole in doses of 5 and 10 mg/kg, respectively, every 3 days for 4 weeks. After the experimental period, the rats were euthanized. One rat died in each group and the study was completed with seven rats in each group. Blood serum was collected for biochemical analysis, and the implants and surrounding bone tissue were used for biomechanical reverse-torque analysis. In the biomechanical analysis, implants that were not properly placed and were not osseointegrated were excluded from the evaluation. Results One-way analysis of variance and Tukey's honestly significant difference test and Student's t test were used for statistical analysis. The reverse-torque test (control (n = 9), OME-1 (N = 7), and OME-2 (n = 7)) analysis of biochemical parameters (alkaline phosphatase, calcium, phosphorus, aspartate aminotransferase, alanine amino transferase, urea, and creatinine) revealed no significant differences between the groups (control (n = 7), OME-1 (N = 7), and OME-2 (n = 7)) (P > 0.05). Conclusions Omeprazole had no biomechanical or biochemical effects on the osseointegration process of titanium implants.Öğe Color Stability of Provisional Restorative Materials in Different Mouthwash Solutions(Hindawi Ltd, 2022) Deger, Yalcin; Bakir, Metin; Demirci, Fatih; Deveci, BuesraPurpose. This study is a comparison of the effects of temporary restorative materials (PRMs) on the color change that occurs due to the use of different mouthwash solutions in two time periods. Material and Methods. One hundred fifty disc-shaped specimens(10 mmx2 mm) were fabricated with three PRMs chemically polymerized PMMA (Imident-I), chemically polymerized bisacrylic composite resin (Acry temp-A), and CAD/CAM PMMA-based polymer (Telio CAD-T) according to manufacturers' instruction and using a CAD/CAM milling system (n=10). CIE L*a*b* values of specimens were recorded before immersion. Samples were immersed in solutions (Distilled water-DW, Kloroben-CHX, Listerine Advanced White-LAW, Listerine Total Care-TC, and Listerine Zero-TCZ) in two time periods (t(1),t(2)). Color measurements of the samples were made with the help of a spectro-photometer before and after they were removed in mouthwashes (VITA Easy shade V).Results. According to the statistical analysis results, significant differences were observed between the results obtained in our study. The highest roughness values in Delta E1 were seen in A-LAW (1.83) and the lowest in T-DW (0.61). In Delta E2, the highest roughness values were observed in I-LAW (2.70), and the lowest in T-DW (1.05). Delta E values of all obtained groups were found within clinically acceptable limits (Delta E < 3.7).Conclusions.The content of temporary restorative materials, the production technique, the type of mouthwash, and the immersion time of the restoration affect the color stability. Mouthwash with a whitening effect caused the most discoloration. Among the temporary restorative materials, it was the CAD/CAM material that best preserved its color stability.Öğe Comparison of marginal and internal adaptation of three-unit fixed dental prostheses made using CAD/CAM metal-free materials(Wiley, 2022) Baran, Melike Cigdem; Demirci, Fatih; Tuzlali, MesutThe aim of this study was to compare the marginal and internal adaptation of three-unit fixed dental prostheses (FDPs) fabricated from different metal-free materials using CAD/CAM methods. A total of 100 three-unit FDPs were produced from a cubic zirconia, a fiber-reinforced resin composite, a polyetheretherketone (PEEK), a polyetherketoneketone (PEKK), and a polymer composite material by the CAD/CAM method (n = 20 per material). The zirconia group was considered the control/reference material. Marginal and internal gap values of the produced FDPs were measured using the silicone replica method at x40 magnification under a stereomicroscope. The obtained data were analyzed using one-way ANOVA and Tukey's HSD tests. The marginal and internal gap values for the cubic zirconia material were found to be statistically significantly lower than those seen for the PEEK, polymer composite, PEKK, and fiber-reinforced resin composite materials. While the marginal and internal adaptation of the cubic zirconia material was found to be better than the others, it should be noted that the marginal and internal gap values for all other materials tested were found to be within the clinically acceptable range.Öğe Comparison of the Effect of Denture Cleansers on Long-Term Water Sorption and Solubility of Polyetheretherketone with other Denture Base Materials(Marmara Univ, Inst Health Sciences, 2022) Demirci, Fatih; Tanik, AbdulsametObjective: In this in vitro study, the effect of three denture cleansers (DCs) after immersion in a chemical solution applied to polyetheretherketone (PEEK) and other denture base materials (DBMs) on long-term water sorption and solubility was compared. Methods: Disk-shaped specimens (50 +/- 1.0-mm diameter and 0.5 +/- 0.1-mm thickness) were prepared from four DBMs (n=48). All specimens were randomly subdivided into four storage media groups (n=12): Corega tablet (CT), Protefix tablet (PT), 1% sodium hypochlorite (NaOCl) solution (SH), and control (distilled water, DW). Storage media were renewed thrice a day for 120 days and simulated for 1-year use of overnight immersion. Water sorption and solubility (mu g/mm3) of DBMs before and after immersion in storage media were examined and obtained data were statistically analyzed using a multivariate analysis of variance, followed by multiple comparisons by a posthoc Tukey's test (p <0.05).Results: From statistical analysis, the effect of different DCs on the water sorption and solubility of DBMs revealed a statistical difference (p<0.05). The PEEK group exhibited a statistical difference in mean water sorption values among all cleanser groups (p<0.05). For the PEEK group, a statistical difference was observed in the DW group among SH and CT groups in terms of the mean solubility values (p<0.05), while a statistically significant difference was not observed in the PT group among SH and CT groups (p> 0.05).Conclusion: DCs affect PEEK and other DBMs in terms of water sorption and solubility in the long-term follow-up.Öğe Comparison of two adhesive systems of various polyetheretherketone (PEEK) composites on the shear bond strength(2021) Demirci, Fatih; Tekin, S.Abstract: Aim: In this in vitro study, the effect of two adhesive systems applied to surfaces of different polyether-ether-ketone (PEEK) composites on the shear bond strength (SBS) of a composite resin was compared. Methodology: Eighty PEEK specimens were divided into four groups (n=20): Unfilled PEEK (UF), carbon-fiber-reinforced PEEK (CFR), glassfiber-reinforced PEEK (GFR), and ceramic-reinforced PEEK (CR). Each group was further divided into two subgroups (n=10): Visio.link (VL) and Single Bond Universal (SB). The specimens with 8-mm diameter and 5-mm thickness were prepared. SBS was examined using a universal testing machine. Results were statistically analyzed by multivariate analysis of variance and Tukey’s post-hoc test. Failure modes were analyzed using a stereomicroscope at 20× magnification. Surface properties were examined by scanning electron microscopy. The surface properties of the specimens were examined by scanning electron microscopy (SEM). Results: Effect of different PEEK and adhesive systems on SBS was found to be statistically significant (p<0.05). SBS values for CFR-VL and UF-VL groups were statistically more significant than those for CFR-SB and UF-SB groups. SBS values for the GFR-VL group were statistically more significant than that for the UF-VL group. SBS values for the CF-SB group were statistically more significant than those for CFR-SB and CFR-SB groups. Failure modes were examined using a stereomicroscope at 20× magnification, and adhesive and mixed failure modes were observed. Conclusion: PEEK composites with different contents and properties can be used in fixed prosthetic restorations. However, additional experimental and clinical studies are required to investigate different PEEK frameworks and composite veneers.Öğe Effect of micro-arc oxidation coatings with graphene oxide and graphite on osseointegration of titanium implants-an in vivo study(Elsevier, 2024) Tekin, Bahar; Dundar, Serkan; Tekin, Samet; Sukuroglu, Ebru Emine; Khurshid, Zohaib; Ezgi, Yusuf; Demirci, FatihBackground: This in vivo study evaluated the effect of graphene oxide and graphite coatings, coupled with the micro-arc oxidation (MAO) surface roughening technique, known for their mechanical strength, chemical stability, and antibacterial properties. The main objective was to assess the degree of improvement in osseointegration of titanium implants resulting from these interventions. Materials and methods: In this study, 32 female rats were utilized and randomly allocated into four groups (n = 8 each): machined surface titanium implants (control), those roughened by the MAO method, those coated with graphene oxide-doped MAO, and those with a graphite-doped MAO coating. Titanium implants were surgically placed in the right tibia of the rats. Rats undergoing no additional procedures during the 4-week experimental period were sacrificed at the end. Then, the implants and surrounding bone tissues were separated and embedded in acrylic blocks for reverse torque analysis. Using a digital torque device, the rotational force was applied to all samples using a hex driver and racquet until implant separation from the bone occurred, with the corresponding values recorded on the digital display. Then, statistical analysis was performed to analyze the data. Results: No statistically significant difference between the groups was observed in the biomechanical bone-implant connection levels (N/cm) (P = 0.268). Post-hoc tests were not required because no discernible differences were identified between the groups. Conclusion: Within the scope of this study, implants treated with the MAO method, along with those coated with graphene oxide- and graphite-doped MAO method, did not exhibit significant superiority in terms of osseointegration compared to machined surface titanium implants.Öğe Effect of ultrasonic scaling and air polishing on the surface roughness of polyetheretherketone (PEEK) materials(Mosher & Linder, Inc, 2022) Demirci, Fatih; Erdem, Merve Birgealp; Tekin, Samet; Caliskan, CevdetPurpose: To evaluate the effects of ultrasonic scaling (US) and air polishing (AP) on four polyetheretherketone (PEEK) composites. Methods: One hundred-twenty 15 x 3 mm discs of PEEK specimens were divided into four groups (n=30): Unfilled PEEK(U-PEEK), carbon fiber-reinforced PEEK(CFR-PEEK), glass fiber-reinforced PEEK(GFR-PEEK), and ceramic-filled PEEK(CF-PEEK). Each group was further divided into three subgroups (n = 10): control, US, and AP. Profilometry and scanning electron microscopy were used to analyze and evaluate surface roughness (SR). Statistical analyses of the data obtained were conducted using Shapiro-Wilk, Welch, and Games-Howell tests. Results: When the SR values of the specimens with US cleaning were evaluated, a statistically significant difference was found between the groups (P< 0.05). When the SR values of the specimens with AP cleaning were analyzed, there was a statistically significant difference in the CF-PEEK group (P< 0.05), whereas the other groups were not significantly different (P> 0.05). More studies are needed on CFR-PEEK and GFR-PEEK materials offered as alternatives to CF-PEEK in dentistry.Öğe Effect of unfiltered cigarettes on marginal bone loss of dental implants: A single center 4-year retrospective clinical study(Mosher & Linder, Inc, 2022) Tanik, Abdulsamet; Demirci, FatihPurpose: This retrospective clinical study evaluated, by radiographic analysis, the effect of unfiltered and filtered tobacco cigarette smoking on marginal bone loss (MBL) in the subjects with dental implants. Methods: In a 4-year retrospective clinical study, 419 dental implants were placed in 188 subjects aged 23-76 years who underwent implant-supported fixed prosthetic restorations. The effects of gender, implant length, implant diameter, implant location, and use of unfiltered and filtered tobacco cigarettes on marginal bone were investigated. MBL was analyzed on the mean, mesial, and distal surfaces of dental implants on periapical radiographs. The results of the data were statistically analyzed with ANOVA and Tukey test. Results: A significant correlation was found between MBL difference and gender, implant length, and implant location (P< 0.05). Smokers had significantly higher MBL than nonsmokers, both within and between groups (P< 0.05). There was a significant difference in MBL in the mesial region in unfiltered cigarette smokers compared to filtered cigarette smokers (P= 0.013). There was a significant increase in MBL in the mesial and distal region compared to heavy smokers of cigarettes without filters (>20 cigarettes/day) and heavy smokers of cigarettes with filters (>20 cigarettes/day) (P< 0.05).Öğe The effects of HAp coating layer on mechanical and optical properties at bonding interface of high-performance polymers(Elsevier, 2023) Demirci, Fatih; Bahce, ErkanPurpose: The effect of hydroxyapatite (HAp) coating layer on mechanical and optical properties at bonding interface of high-performance polymers (HPPs) used in computer-aided design (CAD)/computer-aided manufacture (CAM) technology was investigated in this in vitro study. Materials and methods: Two hundred-twenty specimens were divided into two material groups (n = 110): polyetheretherketone (PEEK, KERA (R) starPEEK) and polyetherketoneketone (PEKK, Pekkton (R) ivory). For mechanical testing, each group was divided into five surface pretreatment subgroups and a control group (n = 10): HAp coating (1%,3%, 5%, and 10% concentrations) and sandblasting with 110-mu m Al2O3 particles. For optical testing, each group was divided into five subgroups (n = 10): HAp coating (1%, 3%, 5%, and 10% concentrations) and control. The effects of the HAp coating on the optical changes and shear bond strength (SBS) of the specimens were investigated. Data was statistically analyzed by one-way ANOVA and Tukey's post-hoc test. Failure modes and surface properties of the specimens were examined by scanning electron microscopy (SEM) and coupled electron dispersive spectroscopy (EDS). Results: Average translucency and color change values increased with increasing HAp coating concentration in HPPs. As a result of the data, statistically significant differences were observed in terms of the effect of the HAp coating on SBS of HPPs (p < 0.05). Failure modes were examined, and mixed failure mode was observed. Conclusion: HAp coating can contribute to the improvement of both the optical properties and bond strength of the HPPs to resin composite. Clinical significance: Adhesion and color problems of high performance polymers are still under discussion. In order to solve these problems, generally focused on surface modifications of these polymers, but the effect of the HAp coating has not been investigated.Öğe Evaluation of the accuracy of dental casts manufactured with 3D printing technique in the All-on-4 treatment concept(Korean Acad Prosthodontics, 2022) Tas, Hilin; Demirci, Fatih; Tuzlali, Mesut; Bahce, Erkan; Avcu, Guler YildirimPURPOSE. The aim of this study is to compare the casts obtained by using conventional techniques and liquid crystal display (LCD) three-dimensional (3D) print techniques in the All-on-4 treatment concept of the edentulous mandibular jaw. MATERIALS AND METHODS. In this study, a completely edentulous mandibular acrylic cast (typodont) with bone-level implants placed with the All -on-4 technique served as a reference cast. In this typodont, impressions were taken with the conventional technique and dental stone casts were obtained. In addition, after scanning the acrylic cast in a dental laboratory scanner and obtaining the Standard Tessellation Language (STL) data, 3D printed casts were manufactured with a 3D printing device based on the design. The stone and 3D printed casts were scanned in the laboratory scanner and STL data were obtained, and then the interimplant distances were measured using Geomagic Control X v2020 (3D Systems, Rock Hill, SC, USA) analysis software (n = 60). The obtained data were statistically evaluated with one-way analysis of variance (ANOVA) and Tukey's pairwise comparison tests. RESULTS. As a result of the one-way ANOVA test, it was determined that the stone casts, 3D printed casts, and reference cast values in all distance intervals conformed to the normal distribution and these values had a significant difference among them in all distance intervals. In Tukey pairwise comparison test, significant differences were found between casts at all distance intervals. In all analyses, the level of significance was determined as .05. CONCLUSION. 3D printed casts obtained with a 3D LCD printing device can be an alternative to stone casts when implants are placed in edentulous jaws. [J Adv Prosthodont 2022;14:379-87]Öğe Evaluation of the demographic profile of patients with implant-supported fixed dental prostheses: A retrospective clinical study(2021) Demirci, Fatih; Tanık, AbdulsametAim: In this study, the aim is to evaluate the demographic profile as well as clinical aspects of patients who received implant-supported fixed dental prostheses (FDPs) between 2016 and 2019 years. Methodology: Among 150 patients with implant-supported FDPs, 120 contacted patients were included in the study. The patients were examined in terms of gender, age groups, edentulism, restoration type, implant location, implant survival rate, and abutment type by using the computer software. Data results were analyzed by descriptive statistical methods. Results: Three hundred and six dental implants were evaluated in a total of 120 patients, 55 men, and 65 women. The average age of the patients was 49.61 ± 11.84, and the most common dental implant application was in the 51–60 age group. Dental implants were frequently applied to the posterior mandible, and 31.9% of them were applied to patients in the 51– 60 age group. A 94.8% implant survival rate was observed. A significant difference was found among age groups with laser-sintered metal-ceramics (LSMC) and all-ceramics (p<0.05). LSMC was the most common type of restoration, and straight abutments were frequently used. Conclusion: Although the survival rate of dental implants is high, implants with a medium length and diameter are frequently used. The type of restoration, type of abutment, and implant location in implantsupported FDPs vary depending on the age and gender of the patients.Öğe Fracture strength of different veneers on polyetheretherketone (PEEK) frameworks in implant-supported single crowns(Mosher & Linder, Inc, 2022) Tekin, Samet; Demirci, Fatih; Bakir, MetinPurpose: To evaluate the fracture strength of polyetheretherketone (PEEK) single crowns veneered with different materials produced by computer-aided design (CAD)-computer-aided manufacture (CAM) after aging. Methods: 60 stainless-steel master dies were prepared with a 1 mm-wide deep chamfer. Sixty PEEK frameworks were produced with a CAD-CAM system for the right maxillary first molar tooth on the dies. PEEK frameworks were divided into six groups (n= 10) according to veneering materials (five CAD-CAM materials and a resin composite). Group ZR: monolithic zirconia (Upcera ST-Color); Group EC: lithium disilicate glass-ceramic (IPS e.max CAD); Group LU: resin nano-ceramic (Lava Ultimate); Group VM: feldspathic ceramic (Vitablocs Mark II); Group VS: zirconia-reinforced lithium silicate glassceramic (VITA Suprinity); and Group CR: indirect resin composite (Gradia). All samples were subjected to a fracture strength test in a universal test device after thermo-mechanical aging and then the results were analyzed statistically using one-way ANOVA and Tukey's post hoc test. In addition, post-fracture analyses of all samples were performed with a stereomicroscope. Results: The differences in fracture strength values of different veneer materials in single crowns with a PEEK framework were statistically significant (P< 0.05). Fracture strength was highest in Group ZR (1665 N), followed by Groups LU (1440 N), EC (1249 N), CR (918 N), VS (754 N), and VM (655 N).Öğe İmplant Destekli Mandibular Overdenture Protezlerin Yaşam Kalitesine Olan Etkisinin Değerlendirilmesi: Pilot Çalışma(2022) Demirci, Fatih; Tanık, AbdulsametAmaç: Bu çalışmanın amacı, mandibular iki implant destekli protezlerin bir grup hastanın yaşam kalitesine etkisini incelemekti. Araçlar ve Yöntem: Bu pilot çalışma, 2016 ve 2020 yılları arasında Adıyaman Üniversitesi Diş Hekimliği Fakültesi'nde implant destekli mandibular overdenture protez isteyen tam dişsiz altmış üç katılımcı (51-83 yaşlarında) ile gerçekleştirildi. Mandibular interforaminal bölgesine iki dental implant yerleştirdikten 6 hafta sonra her hastaya mandibular implant destekli overdenture protezler ile maksiller konvansiyonel tam protezler uygulandı. Hastaların protetik tedavi öncesi ve sonrası yaşam kalitesinin değerlendirilmesi için ağız sağlığı etki profilinin (OHIP-14) Türkçe versiyonu kullanılmıştır. Bulgular: Tedavi öncesi puanlarla karşılaştırıldığında, katılımcılar yeni protezlerini aldıktan sonra yaşam kalitesinde istatistiksel olarak anlamlı iyileşme kaydedildi (p<0.001). Tedavi öncesi ve sonrası OHIP-14 puanları ile cinsiyet arasında ki-kare testinde istatistiksel olarak anlamlı bir ilişki bulunamadı (p>0.05). Sonuç: Bu çalışmanın sonuçlarına dayanarak, mandibular iki implant destekli overdenture protezlerin tam dişsiz hastalarının yaşam kalitesini iyileştirdiği sonucuna varılabilir.Öğe Isolation of rosmarinic acid and methyl rosmarinate as lipoxygenase inhibitors from Salvia palaestina Benth. by activity-guided fractionation(Elsevier, 2021) Icen, Mehmet Sina; Gurbuz, Ilhan; Bedir, Erdal; Gunbatan, Tugba; Demirci, FatihSalvia palaestina aqueous and methanol extracts were prepared from the aerial parts, which were evaluated for the in vitro anti-inflammatory properties using the lipoxygenase (LO) enzyme inhibition assay. While the aqueous extract showed no activity at test concentrations, a significant (p < 0.001) lipoxygenase inhibition was detected for the methanol extract with 29% inhibition. Activity guided fractionation was carried out on the methanol extract via liquid-liquid partitioning using n-hexane, dichloromethane, ethyl acetate, and n-butanol. The ethyl acetate fraction showed statistically the best inhibition among the sub-fractions with 70% inhibition (p < 0.0001). The compounds responsible for the activity were purified, and their structures were established as rosmarinic acid, and methyl rosmarinate by spectroscopic methods. IC50 values of rosmarinic acid, and methyl rosmarinate were calculated as 0.21 and 0.02 mu M, respectively. In conclusion, the in vitro anti-inflammatory potential of S. palaestina was associated to rosmarinic acid, and methyl rosmarinate, for the first time to the best of our knowledge. (C) 2021 SAAB. Published by Elsevier B.V. All rights reserved.Öğe Maksillaya Farklı Açılarda Yerleştirilen İmplantlara Uygulanan Zirkonya-Seramik Kuronların Sonlu Elemanlar Stres Analizi ile Değerlendirilmesi(2021) Demirci, Fatih; Güven, Sedat; Tekin, SametGiriş ve Amaç: Bu çalışmasının amacı, maksillaya uygulanan implant destekli zirkonya-seramik kuronlarda implantların yerleştirme açısının stres dağılımları üzerindeki etkilerinin karşılaştırılmasıdır. Yöntem ve Gereçler: Karşılaştırma için dikey ve oblik yükleme kuvvetleri kullanılmıştır. Birinci büyük azı dişleri eksik olan maksiller kemiğin, implantların ve zirkonya-seramik kuronların üç boyutlu sonlu elemanlı modelleri kullanıldı. 10 mm uzunluğunda, 3,7 mm çapında dental implantlar modellendi. 300 N yük dikey ve oblik (dikey yönde 30°) yönlere uygulandı. İmplantların maksimum ve minimum von Mises stres değerleri hesaplandı. Bulgular: En yüksek stres değeri oblik yükleme kuvveti (663,83 MPa) olan 45° açılı, implant destekli modelin zirkonya alt yapısında yoğunlaştığı görüldü. 45° açılı implant destekli zirkonya-seramik kuron modellerin stres değerleri, diğer açılı implant modellerinden (dikey ve 15° açılı) daha yüksek bulundu. Oblik yükleme kuvvetlerine sahip stres değerleri, dikey yükleme kuvvetlerine göre daha yüksek bulundu. Tartışma ve Sonuç: İmplantların maksillaya yerleştirilme açısı arttıkça, hem implantların boyun kısmındaki hem de implant destekli zirkonya-seramik kuronların servikalindeki stresler de artmaktadır.Öğe Mechanical analysis of three-unit metal-free fixed dental prostheses produced in different materials with CAD/CAM technology(Springer Heidelberg, 2022) Demirci, Fatih; Bahce, Erkan; Baran, Melike CigdemObjectives The aim of this study was to evaluate the mechanical analysis of different three-unit metal-free fixed dental prostheses (FDPs) produced by computer-aided design (CAD)/computer-aided manufacturing (CAM). Materials and methods A hundred stainless steel die models of a mandibular left first premolar and a mandibular left first molar were prepared. The specimens were divided into five CAD/CAM material groups (n = 20): Group ZIR, a cubic zirconia (DD cube ONE (R)); Group FRC, FRC resin material (Trinia); Group PEEK, a PEEK material (KERA (R) starPEEK); Group PEKK, a PEKK material (Pekkton (R) ivory); and Group COMP, a polymer composite material (BreCAM.HIPC). Compression test was applied to the specimens, and then the results were analyzed statistically using one-way ANOVA and Tukey's tests. In addition, deformation analyses in FDPs were compared with finite element method (FEM). After the compression test, the damage to FDPs was evaluated with a scanning electron microscopy. Results Although ZIR (2461 +/- 93.70 N) showed high fracture load values, FRC (1571 +/- 35.96 N) material was found to be advantageous in terms of toughness. These were followed by PEEK (1398 +/- 38.26 N), PEKK (1227 +/- 44.25 N), and COMP (829 +/- 32.33 N), respectively. A ductile fracture was observed in PEEK, PEKK, and FRC due to their elastic structures. The deformation properties examined by the FEM were found to be similar to the compression test. Conclusions CAD/CAM high-performance polymers and cubic zirconia material can be used in three-unit FDPs. In three-unit FDPs, the use of FRC material can be advantageous due to both biomechanics and lightness.Öğe RETROSPECTIVE EVALUATION OF DIFFERENT POST-AND-CORE SYSTEMS IN TEETH RESTORED WITH SINGLE CROWNS(2022) Demirci, Fatih; Çalışkan, CevdetIn this retrospective clinical study, the aim is to evaluate the effect of the clinical survival rates of different post-and-core systems in terms of the age and sex of the population, type of restoration, tooth position, type of post material, effect of opposing dentition, and type of cement used. A retrospective analysis was conducted via spreadsheets that showed patients who were treated with post-and-cores between August 2016 and March 2020. A total of 524 records were included in the analysis according to the inclusion criteria. Data were analysed using Kaplan–Meier and Cox proportional hazards analysis. While a statistically significant difference between the post-and-core survival among age, restoration type, cement type, opposing dentition, and service time was determined (p<0.001), a statistically significant difference with tooth position and sex was not detected (p>0.05). The analyzes showed no evidence that different post-and-core systems (prefabricated glass and carbon fiber reinforced composite resin, cast metal and prefabricated metal) were significantly associated with post-and-core survival. However, opposing dentition, type of cement, and restoration exhibited a statistically significant difference with the post-and-core survival.
