Protetik Diş Tedavisi Ana Bilim Dalı Koleksiyonu
Bu koleksiyon için kalıcı URI
Güncel Gönderiler
Yayın Farklı dental tarayıcı teknolojilerinin doğruluklarının değerlendirilmesi: In-Vitro çalışma(7tepe Klinik, 2024) Ayvalıoğlu Şamiloğlu, Demet Çağıl; Beydili, Serra NurGİRİŞ ve AMAÇ: Diş hekimliğinde dijital teknolojinin kullanımı CAD/ CAM sistemlerinin hayatımıza girmesiyle son yıllarda oldukça artmıştır. CAD/CAM sistemleri ile bir iş akışı ağız içi tarayıcılarla direkt veya masaüstü tarayıcılarla indirekt yöntem ile başlayarak takip edilebilir. Bu çalışmanın amacı, tam ark dişli çenelerde masaüstü tarayıcı ve ağız içi tarayıcıların doğruluklarının değerlendirilmesidir. YÖNTEM ve GEREÇLER: Tam ark dişli çene modelinde yer alan kanin ve molar dişleri üzerinde, ISO standartları çerçevesinde, dört adet 6 mm çapında negatif küre oluşturulmuştur. Standart ışıksız ortamda, model, Dijital Şerit Projeksiyon Teknolojisi, Aktif Triangulasyon ve Konfokal Mikroskopi teknolojilerine sahip tarayıcılar ile firmanın önerdiği tarama protokolleriyle 20 kez taranarak dijitalize edilmiştir. Kontrol grubu, referans dijital data, endüstriyel tarayıcı (Solutionix C500, MEDIT) ile elde edilmiştir. Elde edilen tüm dijital data, 3 boyutlu (3B) analiz yazılım programı ile değerlendirilmiştir (Geomagic studio 2015; 3D Systems Inc., Almanya). Normal dağılan veriler için tek yönlü ANOVA ve post hoc Bonferroni testi, normal dağılmayan veriler için Bonferroni, Kruskal-Wallis testi ile değerlendirilmiştir (α=0,05). BULGULAR: Tam ark dişli model taramalarının doğruluğu, masaüstü tarayıcı ve ağız içi tarayıcıların tipine bağlı olarak anlamlı farklılık göstermiştir (p˂0,05). Her iki ağız içi tarayıcı arasında tarama doğruluğu bakımından istatistiksel olarak anlamlı fark bulunmuştur (p˂0,05). TARTIŞMA ve SONUÇ: Tam ark taramalarda dijital sistemlerin kullanılması klinik olarak kabul edilebilir sonuçlar göstermektedir.Yayın Effect of scanbody material and mucosa modification technique on the accuracy of digital impressions of edentulous arches with multiple implants(Necmettin Erbakan University, 2024) Göksoy, Görkem; Ayvalıoğlu Şamiloğlu, Demet Çağıl; Gökçen-Röhlig, BilgeAim: The aim of current research is to evaluate the effect of scanbody material and additional reference markers in the form of artificial landmarks on the accuracy of digital impressions of edentulous arches with multiple implants. Material and Methods: A model of an edentulous maxilla with six implants (BLT, RC, Institut Straumann, AG) was used as master model. PEEK and PMMA scanbodies were screwed on the implants and digital impressions were obtained with an intraoral scanner (TRIOS4, 3Shape). Reference markers made of flowable composite (C), gingival barrier material (GB), scannable silicone (S) were placed on the edentulous spaces and impressions were obtained. The master model was digitalized with an extraoral highresolution reference scanner. Deviations of the predetermined points and inter-implant distances were calculated by using superimpositining technique. Results: Inter-implant distance measurements showed that PEEK scanbodies demonstrated better precision than PMMA scanbodies, (p<.001). In the subgroups, also PEEK groups were more accurate than PMMA groups (p<.001). Kruskal-Wallis test also showed statistical difference in deviations of the predetermined points among the groups in precision (p<.001). Addition of markers did not influence the precision and trueness in PEEK groups but in PMMA groups both in distance measurements and predetermined point deviations. Conclusion: Addition of reference markers does not make any significance in the accuracy of digital impressions when PEEK scanbodies are used. PMMA seems not to be an alternative material as scanbody material, addition of markers is needed.Yayın Evaluation of stress distributions in all ceramic conometric single crown restorations: 3-dimensional finite element analysis(Marmara Üniversitesi, 2024) Vural, Sinem; Evren, Buket; Yıldız, CoşkunObjective: The aim of the study is to compare the effect of monolithic translucent zirconia ceramic (TZI) and monolithic lithium disilicate glass ceramic (LDS) restorative materials on stress distributions in implant components and surrounding bone tissues in implant-supported conometric single crown restorations with a conical connection system by using 3D finite element analysis. Methods: Restorations produced with two different all-ceramic materials using a conometric abutment and a conometric cap on the implant with a conical connection system were placed in the maxillary right second premolar region. 3D finite element analysis was used to examine the amount and distribution of stresses in implant components, in cortical and cancellous bone tissues surrounding the implant and in crowns under vertical and oblique loading. For the statistical analysis one-way ANOVA and independent samples t-test were used (p<.05). Results: In oblique 100N simulation, maximum stress distribution in implant and its components occurred at the implant abutment contact as 475.63 MPa for the LDS. The screw’s peak stress values were determined to be 239.09 MPa in the transition zone and 280.061 MPa in the thread. On the bone surface, maximum and minimum cortical principal stress values were 61.25 MPa and – 62.028 MPa. During oblique loading, LDS exhibited the greatest surface stress on the cap as 441.33 MPa. Generally, tapping phase showed the lowest stress (p<.05). There was no significant difference regarding the materials (p> .05). Conclusion: von Misess and principal stresses are not very high in any location therefore conical connections are more promising in terms of future success.Yayın Comparison of fiber reinforcing methods of composite resin: Aflexural strength and stereo microscopy study(Wiley, 2023) Cengiz, Seda; Bağış, Bora; Külünk, Şafak; Velioğlu, Neslin; Sağlam, GayeThis study aimed to compare the effect of fiber reinforcing methods on the flexural strength and failure modes of indirect composite resins. Based on the reinforcement methods, the bar specimens (3 x 3 x 25 mm) were divided into five groups (n = 20). Glass or polyethylene fibers were used for reinforcement of indirect composite resins. Fibers were either light polymerized and mixed with indirect composite resin or mixed with indirect composite resin after resin application and polymerized together. Indirect composite resin without fiber reinforcement was used as control. All five types of specimens were stored in distilled water at 37 & DEG;C for 24 h. Half of the specimens were additionally thermocycled. Then the specimens were tested in a three-point bending test. Failure types were examined and categorized by using stereo microscope. The data were analyzed using two-way ANOVA and Tukey HSD test. Flexural strength was found to be significantly higher for fiber-reinforced indirect resin composites than control. However, the fiber-reinforced groups did not present any significant difference. Analysis revealed aging does not affect the flexure strength of fiber reinforcement of indirect composite resin. The study concluded that the flexure strength of indirect composite resins was improved with fiber reinforcement. Different fiber reinforcement methods demonstrated similar effects on the flexure strength of indirect composite resin. Reinforcement with glass or polyethylene fibers presented the potential to improve the mechanical properties of indirect composite resins. Research Highlights Flexural strength of indirect composite resins are affected by the reinforcement of composites with glass or polyethylene fibers. Aging with thermocycling has no effect on the flexural strength of the indirect composite resins, however can cause catastrophic failures in material.Yayın Evaluation of the effect of anodization-colored titanium abutments and zirconia substructure thickness on zirconia substructure color: An In vitro study(Wolters Kluwer Health, 2022) Baş, B. B.; Çakan, UmutBackground and aim: The aim of this study is to evaluate the effect of anodized titanium abutments and zirconia substructure thickness on the color of zirconia substructure. Materials and methods: In this study, an electrochemical anodization setup was prepared for titanium coloring. Commercial titanium, anodization-colored yellow and pink titanium, and zirconia were used as different abutment specimens. Thirty zirconia discs in 0.7, 0.9, and 1.1 mm thickness were prepared from zirconia blocks as zirconia substructure specimens (n = 10). Zirconia substructure specimens of different thicknesses were placed on abutment specimens of different colors and L*, a*, b* values were measured with a spectrophotometer device. Color difference (ΔE) was calculated according to the CIELab formula by comparing the L*, a*, and b* values obtained on the zirconia abutment with the L*, a*, and b* values obtained on the other abutments. Statistical analyzes were performed with two-way analysis of variance and Tukey Honestly Significant Difference (HSD)test (p < 0.05). Results: The increase in the thickness of the substructure resulted in a statistically significant difference on ΔE, L*, a*, and b* values (p < 0.001). The effect of abutment color had no significant effect on ΔE values. The highest ΔE value was 18.10 at zirconia substructure with 0.7 mm thickness when paired with pink-anodized titanium abutment specimens. Conclusion: The thickness of zirconia substructure and the color of titanium abutments affect zirconia substructure color.
