Yazar "Türksayar, Almira Ada Diken" seçeneğine göre listele

Listeleniyor 1 - 7 / 7
  • Küçük Resim Yok
    Öğe
    Dimensional stability of additively manufactured dentate maxillary diagnostic casts in biobased model resin
    (MDPI, 2024) Demirel, Münir; Türksayar, Almira Ada Diken; Petersmann, Sandra; Spintzyk, Sebastian; Dönmez, Mustafa Borga
    This study aimed to evaluate the dimensional stability of maxillary diagnostic casts fabricated from a biobased model resin, which consists of 50% renewable raw materials for sustainable production, a model resin, and stone, over one month. A master maxillary stone cast was digitized with a laboratory scanner to generate a reference file. This master cast was also scanned with an intraoral scanner to additively manufacture casts with a biobased model resin (BAM) and a model resin (AM). Polyvinylsiloxane impressions of the master cast were also made and poured in type III stone (CV) (n = 8). The same laboratory scanner was used to digitize each model one day (T0), 1 week (T1), 2 weeks (T2), 3 weeks (T3), and 4 weeks (T4) after fabrication. Deviations from the reference file were calculated with an analysis software and analyzed with generalized linear model analysis (alpha = 0.05). The interaction between the material and the time point affected measured deviations (p < 0.001). Regardless of the time point, CV had the lowest and AM had the highest deviations (p < 0.001). BAM mostly had lower deviations at T0 and mostly had higher deviations at T4 (p <= 0.011). AM had the highest deviations at T4 and then at T3, whereas it had the lowest deviations at T0 (p <= 0.002). The measured deviations of CV increased after each time point (p < 0.001). BAM casts had deviations within the previously reported clinically acceptable thresholds over one month and had acceptable dimensional stability. Therefore, tested biobased resin may be a viable alternative for the sustainable manufacturing of maxillary diagnostic casts that are to be used clinically.
  • Küçük Resim
    Öğe
    Effect Of Intraoral Scanner On The Scan Accuracy Of Different Restoration Designs
    (Ankara Dişhekimleri Odası, 14.06.2024) Demirel, Münir; Türksayar, Almira Ada Diken; Donmez, Mustafa Borga
    Objective: The aim of this in vitro study was to evaluate the effect of intraoral scanner used in different preparation geometries on trueness and precision. Materials and Methods: Three different dental models of inlay, onlay and full crown preparation designs were used in the study. Reference scans were performed with an industrial-grade scanner (ATOS Core 80, GOM), while each model was scanned 10 times with the following intraoral scanners, respectively: Trios 4 (3Shape), Trios 3 (3Shape), Primescan (Dentsplay Sirona), Omnicam (Dentsplay) Sirona), Planmeca Emerald (Planmeca), Medit i700 (Medit Corp). All scan data were converted to STL file and saved. Then, the data were recorded in the 3D image processing software (Geomagic Control X 2020.1) and the accuracy and precision values were calculated. Shapiro Wilk, two-way ANOVA and post hoc Tukey tests were performed for statistical analysis. Results: Both the geometry of the preparation and the intraoral scanner used were found to be effective in the accuracy analysis. The highest accuracy values were obtained in the full crown design and with the Medit i700. The precision values of the full crown preparation were found to be higher in all intraoral scanners except Trios 4, but there was no significant difference between the scanners. Conclusion: It should be considered that the accuracy and sensitivity of the preparations with complex geometries may decrease depending on the intraoral scanner used.
  • Küçük Resim Yok
    Öğe
    Effect Of Intraoral Scanner On The Scan Accuracy Of Different Restoration Designs
    (Ankara Diş Hekimleri Odası, 26 Ocak 2024) Demirel, Münir; Türksayar, Almira Ada Diken; Dönmez, Mustafa Borga
    Objective: The aim of this in vitro study was to evaluate the effect of intraoral scanner used in different preparation geometries on trueness and precision. Materials and Methods: Three different dental models of inlay, onlay and full crown preparation designs were used in the study. Reference scans were performed with an industrial-grade scanner (ATOS Core 80, GOM), while each model was scanned 10 times with the following intraoral scanners, respectively: Trios 4 (3Shape), Trios 3 (3Shape), Primescan (Dentsplay Sirona), Omnicam (Dentsplay) Sirona), Planmeca Emerald (Planmeca), Medit i700 (Medit Corp). All scan data were converted to STL file and saved. Then, the data were recorded in the 3D image processing software (Geomagic Control X 2020.1) and the accuracy and precision values were calculated. Shapiro Wilk, two-way ANOVA and post hoc Tukey tests were performed for statistical analysis. Results: Both the geometry of the preparation and the intraoral scanner used were found to be effective in the accuracy analysis. The highest accuracy values were obtained in the full crown design and with the Medit i700. The precision values of the full crown preparation were found to be higher in all intraoral scanners except Trios 4, but there was no significant difference between the scanners. Conclusion: It should be considered that the accuracy and sensitivity of the preparations with complex geometries may decrease depending on the intraoral scanner used.
  • Küçük Resim
    Öğe
    Farklı intraoral tarayıcıların implant ölçü hassasiyeti üzerindeki etkisinin değerlendirilmesi
    (Ankara Diş Hekimleri Odası, 26 Ocak 2024) Ceylan, Gülsüm; Demirel, Münir; Türksayar, Almira Ada Diken; Emir, Faruk; Dönmez, Mustafa Borga
    Amaç: Bu in vitro çalışmanın amacı intraoral tarayıcıların dental implantlar üzerinden alınan ölçülerin hassasiyetine olan etkisini kapsamlı bir şekilde değerlendirmektir. Gereç ve Yöntem: Bu çalışma, altı intraoral tarayıcıyı (AİT); Trios 4, Trios 3, Primescan, Omnicam, Planmeca ve Medit i700 karşılaştırmak üzerine tasarlandı. 3D yazıcı (Formlabs 3) ile üretilen master modelden herbir AİT ile ölçü alındı. AİT’lerin doğruluk (trueness) ve kesinlik (precision) değerleri belirlendi ve analiz edildi. İstatistiksel analizlerde, Shapiro-Wilks testi ve Kruskal-Wallis non-parametrik testleri (α=0.05) ayrıca çoklu karşılaştırmalarda Tamhane testi kullanıldı. Bulgular: Gruplara ait doğruluk değerleri arasında anlamlı farklar bulundu (p<0.05). Trios 4 ile Omnicam doğruluk değerleri arasında istatistiksel olarak anlamlı bir fark bulunmazken (p>0.05) diğer AİT’ler ile arasında anlamlı fark bulundu (p<0.05). Trios 3 ile Planmeca arasında istatistiksel olarak anlamlı bir fark bulunmadı (p>0.05). Ancak, Primescan ve Medit i700'ün doğruluk değerleri ile diğer AİT'ler arasında istatistiksel olarak anlamlı fark bulundu (p<0.05). Gruplara ait kesinlik değerleri arasında anlamlı farklar saptandı (p<0.05). Medit i700 ve Omnicam, Trios 3 ve Trios 4 arasında istatistiksel olarak anlamlı fark bulunurken (p<0.05), Planmeca ile diğer AİT’ler arasında anlamlı fark bulunmadı (p>0.05). Sonuç: En yüksek doğruluk değeri Primescan'de, en yüksek kesinlik değeri ise Medit i700'de bulundu. Bu sonuçlar, AİT’lerin seçiminde hekimler tarafından dikkate alınmalıdır.
  • Küçük Resim
    Öğe
    Optical properties, biaxial flexural strength, and reliability of new-generation lithium disilicate glass-ceramics after thermal cycling
    (WILEY, 2023) Türksayar, Almira Ada Diken; Demirel, Münir; Dönmez, Mustafa Borga
    PurposeTo investigate the color stability, translucency, biaxial flexural strength (BFS), and reliability of nano-lithium disilicate and fully crystallized lithium disilicate after thermal cycling and to compare with those of a commonly used lithium disilicate. Materials and methodsThree lithium disilicate glass-ceramics were used to prepare disk-shaped specimens (o:12 mm, thickness: 1.2 mm) from A2 shaded HT blocks (Amber Mill, AM; Initial LiSi Block, IN; IPS e.max CAD, EX). AM and EX specimens were crystallized, and all specimens were polished with a polishing paste (Diamond Polish Mint). A spectrophotometer (CM-26d) was used to measure color coordinates before and after thermal cycling. BFS test was performed after thermal cycling. Color differences (Delta E-00) and relative translucency parameter (RTP) values were calculated. One-way analysis of variance (ANOVA) (Delta E-00 and BFS), two-way ANOVA followed by Tukey's HSD tests (RTP), and chi-square tests (Weibull modulus and characteristic strength) were used for the statistical analyses (alpha = 0.05). ResultsNo significant differences were observed among the Delta E-00 values of tested materials (df = 2, F = 2.933, p = 0.070). RTP values were only affected by material type (p < 0.001) as AM had the highest RTP (p < 0.001), whereas IN and EX had similar values (p >= 0.165). BFS values varied among tested materials (df = 2, F = 21.341, p < 0.001). AM and EX had similar BFS values (p = 0.067) that were higher than that of IN (p <= 0.001). Weibull moduli of the materials were similar (p = 0.305), whereas EX had the highest and IN had the lowest characteristic strength values (p < 0.001) ConclusionsAlthough nano-lithium disilicate had the highest translucency, all materials had imperceptible color and translucency changes after thermal cycling when reported threshold values were considered. Newly introduced lithium disilicate glass-ceramics had adequate flexural strength as compared to the precursor material.
  • Küçük Resim
    Öğe
    Stress behavior of an anterior single implant restored with high-performance polymer abutments under immediate and delayed loading: A 3D FEA study
    (WILEY, 2022) Türksayar, Almira Ada Diken; Dönmez, Mustafa Borga
    Purpose To evaluate the stress generated on peripheral bone, implant, and prosthetic components while using polyetheretherketone (PEEK) and polyetherketoneketone (PEKK) hybrid abutments in two different loading situations with nonlinear 3D finite element analysis. Materials and methods Standard tessellation language (STL) files of original components were used for the in-silico modeling of implant, standard titanium abutment, and hybrid abutments (PEEK and PEKK). The implant was placed in the bone block to imitate immediate loading, in which a friction coefficient of 0.3 was set between the bone and the implant interface, or delayed loading, where the bone-implant interface was assumed to be perfect. In all models, both a horizontal force (25.5 N) and a 30-degree oblique force (178 N) were applied to the long axis of the implant to the palatal surface of the restoration. The stress distribution was evaluated. Results While more stress was observed in the prosthetic structures in the PEEK and PEKK models, the stresses on the implant and bone were similar in all models, regardless of the loading situation. Under immediate loading, PEEK hybrid abutments caused excessive stress accumulation on the titanium base abutment. Conclusions Even though abutment type did not affect the stresses on peripheral bone, PEEK and PEKK abutments generated greater stresses on the implant and the standard titanium abutment accumulated higher stresses. Oblique forces mostly generated greater stress than horizontal forces. Oblique forces on an immediately loaded implant led to stresses higher than the yield strength of a titanium implant when restored with PEEK hybrid abutment.
  • Küçük Resim
    Öğe
    Translucency, color stability, and biaxial flexural strength of advanced lithium disilicate ceramic after coffee thermocycling
    (WILEY, 2022) Demirel, Münir; Türksayar, Almira Ada Diken; Dönmez, Mustafa Borga
    Objective To compare the color stability, translucency, and biaxial flexural strength (BFS) of differently glazed advanced lithium disilicate (ALDS) with those of lithium disilicate (LDS) and zirconia-reinforced lithium silicate (ZLS) after coffee thermocycling. Materials and methods Forty disk-shaped specimens were prepared from three lithium silicate based materials (CEREC Tessera, ALDS; IPS e.max CAD, LDS; Vita Suprinity, ZLS). ALDS specimens were divided into two subgroups according to glazing procedures (reduced glaze duration, ALDS-S and normal glaze duration, ALDS-N), while LDS and ZLS specimens were crystallized and glazed. Color coordinate measurements were performed before and after coffee thermocycling. Color differences (Delta E-00) and relative translucency parameters (RTP) were calculated. Specimens were then subjected to BFS test. Statistical analysis was performed by using 1- (Delta E-00 and BFS) and 2-way (RTP) ANOVA tests (alpha = 0.05). Results Delta E-00 values of tested materials were similar (df = 3, F = 0.150, p = 0.929). Two-way ANOVA showed the significant effect of material type, coffee thermocycling, and the interaction between these parameters on RTP values (p < 0.001). Both before and after thermocycling, LDS had the highest (p <= 0.001) and ZLS had the lowest (p < 0.001) RTP values, while ALDS-N had higher RTP than ALDS-S (p <= 0.001). Among tested materials, only LDS had similar RTP values before and after thermocycling (p = 0.865) as the other materials had lower RTP values after thermocycling (p < 0.001). ALDS-N had higher BFS values than ALDS-S (p = 0.005), while LDS had similar values to ALDS specimens (p >= 0.201). ZLS had the highest BFS (p <= 0.007). Conclusions ALDS had comparable values to those of other materials. However, reduced glazing duration resulted in decreased translucency and BFS of ALDS. Clinical significance ALDS may be an appropriate restorative material for those patients with increased coffee consumption considering its color stability and ability to maintain translucency, particularly when glazed by using a conventional porcelain furnace.