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    Cone beam computed tomography vs. microcomputed tomography for trabecular bone healing assessment
    (Urban & Vogel, 2025) Deniz, Yesim; cetin Genc, Cigdem; Orhan, Kaan
    PurposeThis study aimed to compare cone beam computed tomography (CBCT) and microcomputed tomography (mu CT) data to evaluate the micromorphological structure of healing bone in defects created on rabbit mandibles at different stages.MethodsResidual rabbit mandibular alveolar bone tissues from another animal study involving 18 rabbits were utilized. In the prior study, 10 x 4 mm bone cavities were created, left to heal naturally, and the animals were sacrificed after 21, 45, and 90 days. In this study, CBCT and mu CT imaging were performed on the excised defect regions. The micromorphometry parameters including bone-volume fraction (BV/TV), bone-surface density (BS/TV), fractal dimension, connectivity density (Conn. Dn.), trabecular thickness (Tb.Th), and trabecular separation (Tb.Sp) were examined by ImageJ (US National Institutes of Health, Bethesda, MD, USA). Paired two-sample t-tests, Wilcoxon test, and Bland-Altman plots were performed.ResultDifferences in the parameters Conn. Dn., fractal dimension, Tb.Th, and Tb.Sp were observed between CBCT and mu CT on day 21. By day 45, no significant differences were noted in BV/TV, BS/TS, Tb.Th, and Tb.Sp. On day 90, all measured parameters showed no statistically significant differences between CBCT and mu CT. Bland-Altman analysis showed an agreement for most parameters (BV/TV, BS/TV, fractal dimension, Tb.Th, and Tb.Sp) after 21, 45, and 90 days, with minimal biases emerging over time, while a more notable divergence in Conn. Dn. was observed.ConclusionCBCT can be used for micromorphological analyses on days 45 and 90 of bone healing as there were no differences between CBCT and mu CT during these periods. ZielIn dieser Studie sollten CBCT- (digitale Volumentomographie) und mu CT(Mikro-Computertomographie)-Daten verglichen werden, um die mikromorphologische Struktur der Knochenheilung in artifiziell erzeugten Defekten an Kaninchenunterkiefern in verschiedenen Stadien zu untersuchen.MethodeVerwendet wurde Restgewebe des Alveolarknochens von Kaninchen aus einer anderen Tierstudie mit 18 Kaninchen. In der vorangegangenen Studie wurden 10 x 4 mm gro ss e Knochendefekte geschaffen, die nat & uuml;rlich ausheilen sollten, und die Tiere wurden nach 21, 45 und 90 Tagen get & ouml;tet. In der vorliegenden Studie wurden CBCT- und mu CT-Aufnahmen der exzidierten Defektregionen durchgef & uuml;hrt. Die mikromorphometrischen Parameter einschlie ss lich Knochenvolumenanteil (BV/TV), Knochenoberfl & auml;chendichte (BS/TV), fraktale Dimension, Konnektivit & auml;tsdichte (Conn. Dn.), Trabekeldicke (Tb.Th) und Trabekelseparation (Tb.Sp) wurden mit ImageJ (US National Institutes of Health, Bethesda, MD, USA) untersucht. Durchgef & uuml;hrt wurden gepaarte Zwei-Stichproben-Tests, der Wilcoxon-Test und Bland-Altman-Diagramme.ErgebnisUnterschiede bei den Parametern Conn. Dn., fraktale Dimension, Tb.Th und Tb.Sp wurden zwischen CBCT und mu CT am 21. Tag festgestellt. Am 45. Tag wurden keine signifikanten Unterschiede bei BV/TV, BS/TS, Tb.Th und Tb.Sp festgestellt. Am 90. Tag zeigten alle gemessenen Parameter keine statistisch signifikanten Unterschiede zwischen CBCT und mu CT. Die Bland-Altman-Analyse zeigte eine & Uuml;bereinstimmung f & uuml;r die meisten Parameter (BV/TV, BS/TV, fraktale Dimension, Tb.Th und Tb.Sp) am 21., 45. und 90. Tag, wobei im Laufe der Zeit nur minimale Abweichungen auftraten, w & auml;hrend eine deutlichere Divergenz bei Conn. Dn. beobachtet wurde.SchlussfolgerungDie CBCT kann f & uuml;r mikromorphologische Analysen am 45. und am 90. Tag der Knochenheilung verwendet werden, da es in diesen Zeitr & auml;umen keine Unterschiede zwischen CBCT und mu CT gab.
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    Determination and classification of intraoral phosphor storage plate artifacts and errors
    (Korean Acad Oral & Maxillofacial Radiology, 2019) Deniz, Yesim; Kaya, Seher
    Purpose: The aim of this study was to determine the reasons and solutions for intraoral phosphor storage plate (PSP) image artifacts and errors, and to develop an appropriate classification of the artifacts. Materials and Methods: This study involved the retrospective examination of 5,000 intraoral images that had been obtained using a phosphor plate system. Image artifacts were examined on the radiographs and classified according to possible causative factors. Results: Artifacts were observed in 1,822 of the 5,000 images. After examination of the images, the errors were divided into 6 groups based on their causes, as follows: images with operator errors, superposition of undesirable structures, ambient light errors, plate artifacts (physical deformations and contamination), scanner artifacts, and software artifacts. The groups were then re-examined and divided into 45 subheadings. Conclusion: Identification of image artifacts can help to improve the quality of the radiographic image and control the radiation dose. Knowledge of the basic physics and technology of PSP systems could aid to reduce the need for repeated radiography.
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    The impact of remineralization agents on dental bleaching efficacy and mineral loss in bleached enamel
    (Wiley, 2022) Misilli, Tugba; Carikcioglu, Burak; Deniz, Yesim; Aktas, Cagatay
    This study evaluated the effect of remineralization agents on bleaching efficiency, enamel mineral changes, and post-bleaching color stability. A total of 112 enamel-dentin blocks were prepared from bovine teeth. Following initial color measurements, separate treatment regimens were carried out as follows: negative control (no treatment); positive control (bleaching only); bleaching, then NaF; bleaching + NaF (mix); bleaching, then CPP-ACPF; bleaching + CPP-ACPF (mix); bleaching, then nHAP+F; bleaching + nHAP+F (mix). Color measurements were repeated after immersion in distilled water for 7 days, and again after staining with coffee solution for 14 days. The CIELAB-based whiteness index was used to evaluate bleaching efficiency, and the CIEDE2000 color difference formula for color stability. Chemical investigation was performed using scanning electron microscopy with energy dispersive spectroscopy and X-ray diffraction analyses. The experimental groups showed significant increases in whiteness compared to the negative control, and the staining after bleaching did not result in statistically significant differences between the groups. Energy dispersive spectroscopic analysis revealed that bleaching protocols had no impact on elemental levels as well as the ratio of Ca/P. The combined use of bleaching agents with remineralization agents did not affect bleaching effectiveness but also did not provide an additional contribution.