Browsing by Author "Erkut, Selim"

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Anterior diş şekillerinin yüksek gülme hattına sahip hastalarda estetik parametreler üzerine etkisi
(Başkent Üniversitesi Sağlık Bilimleri Enstitüsü, 2022) Sakallı, Onur Altuğ; Erkut, Selim
Gülümseme insanın kendisini ifade ettiği sözlü olmayan iletişimin en iyi yollarından birisidir. Gerek estetik kaygılar ile gerekse de diş kayıpları nedeni ile gülüşün yeniden tasarlanması gerektiği durumlarda anterior diş şekillerinin belirlenmesi çok önemlidir. Özellikle yüksek diş eti görünürlüğü (gummy smile) olan hastalarda diş şekilleri gülüş sırasında kapladığı yer açısından fark yaratacaktır. Anterior diş şekilleri çeşitli literatürlerde yüz şekli ile ilişkilendirilse de herhangi bir bağlantının olmadığını öne süren yayınlar da vardır. Yapılan çalışmalarda popülasyonda gummy smile’a sahip bireylerin oldukça yaygın olduğu gösterilmiştir. Bundan dolayı da kliniğe başvuran hastaların büyük bir çoğunluğunda gummy smile olacağını varsayılabilir. Gummy smile hastalarında uygulanacak olan restoratif işlemler de estetik açıdan daha zorlayıcı olacaktır. Tez çalışmasında diş formu farklarının özellikle yüksek diş eti görünürlüğü olan hastalarda estetik kabul edilebilirlik açısından değerlendirilecektir. Sonrasında yüz şekilleri ile diş şekilleri karşılaştırılıp günlük klinik kullanımında anterior diş şekillerini değiştirerek estetik olarak daha kabul edilebilir sonuçlara nasıl ulaşılacağı amaçlanmaktadır. Adobe Photoshop CS programı kullanılarak onam alınmış modellerin yüzleri birleştirilerek kimliksiz bir yüz oluşturulmuştur. Daha sonra elde edilen bu yüz literatürde yer alan kare, oval ve üçgen formlara göre ayarlanmıştır. Modellerden elde edilen diş fotoğrafları literatürde yer alan kare, oval ve üçgen formlara getirilip yüzler ile birleştirilmiştir. Birleştirilen yüzlerde diş eti seviyeleri normal ve gummy smile seviyesinde olacak şekilde ayarlanmıştır. Diş eti rengi ve dudak rengi algısını da değerlendirmek için dudak rengi ve diş eti rengindeki kırmızı rengi %20 oranında arttırılıp azaltılarak yeni modeller elde edilmiştir. Elde edilen modeller Free Online Surveys (www.freeonlinesurveys.com) internet sitesi kullanılarak mobil uyumlu bir anket haline getirilmiştir. Çalışma sonuçlarına göre gruplarda diş şekilleri ve yüz şekilleri arasında bir uyum büyük oranda gözlenmemiş olup gummy smile diş eti seviyesinde diş görünürlüğü en fazla olan kare modeller en az oranda tercih edilmiştir. Diş eti dağılımı daha dengeli olan oval ve üçgen diş formları daha yüksek oranda tercih edilmiştir. Sonuçlara göre %20 oranında daha kırmızı dudak rengi bütün çalışma gruplarınca yüksek oranda tercih edilmiş olup diş eti rengi açısından bakıldığında da normal diş eti rengi daha yüksek oranda estetik bulunmuştur. Çalışma sonuçlarının özellikle yüksek estetik beklentiye sahip ve de gummy smile hastalarına uygulanan ön bölge restorasyonlarında diş formlarını değiştirerek beğeni oranını nasıl arttırabileceğine dair klinisyenlere bir rehber olması amaçlanmaktadır. Bu çalışma Başkent Üniversitesi Tıp ve sağlık Bilimleri Araştırma Kurulu tarafından onaylanmış (Proje no:D-KA22/01) ve Başkent Üniversitesi Araştırma Fonunca desteklenmiştir. Smiling is one of the best ways of non-verbal communication in which people express themselves. It is very important to determine the anterior tooth shapes in cases where the smile needs to be redesigned for not only aesthetic concerns but also for tooth loss. Especially in patients with high gingival visibility (gummy smile), tooth shapes makes a difference in terms of the space they occupy during smiling. Although anterior tooth shapes are associated with face shape in various doctrines, there are also studies suggesting that there is no such connection. Studies have shown that individuals with a gummy smile are very common in the population. Therefore, it can be assumed that the majority of patients who apply to the clinic will have a gummy smile. Restorative procedures to be applied in gummy smile patients will also be more aesthetically challenging. In the thesis study, tooth form differences are evaluated in terms of aesthetic acceptability, especially in patients with high gingival visibility. Afterwards, it is aimed to compare the face shapes and tooth shapes and how to achieve more aesthetically acceptable results by changing the anterior tooth shapes in daily clinical use. An unidentified face was created, using the Adobe Photoshop CS program, combining the faces of the models whose consent was taken. Later, this face was adjusted in accordance with the doctrine, in square, oval and triangular forms. The dental photographs obtained from the models were combined with the faces that were brought into square, oval and triangular forms in the doctrine. The gingival levels were adjusted to be normal and gummy smile levels in the joined faces. In order to evaluate the perception of gingival color and lip color, new models were obtained by increasing and decreasing the red color in the lip and gingival color by 20%. Obtained models were turned into a mobile compatible survey using the Free Online Surveys (www.freeonlinesurveys.com) website According to the results of the study, no substantial harmony was observed between the tooth shapes and face shapes in the groups, and the square models with the highest tooth visibility at the gummy smile gingival level were preferred the least. Oval and triangular tooth forms with a more balanced gingival distribution were preferred at a higher rate. According to the results, 20% redder lip color was highly preferred by all study groups, and in terms of gingival color, normal gingival color was found to be more aesthetically pleasing. It is aimed that the results of the study would be guidance for clinicians on how to increase the rate of appreciation by changing the tooth forms in anterior region restorations applied especially to patients with high aesthetic expectations and gummy smile. This study was approved by the Baskent University Medical and Health Sciences Research Board (Project no: D-KA22/01) and was supported by the Baskent University Research Fund.
A Clinical Comparison of Cordless and Conventional Displacement Systems Regarding Clinical Performance and Impression Quality
(2014) Acar, Ozlem; Erkut, Selim; Ozcelik, Tuncer Burak; Ozdermr, Erdem; Akcil, Mehtap; https://orcid.org/0000-0001-5685-4409; 24360008; JJF-5618-2023
Statement of problem. it is not clear whether newly introduced cordless displacement systems are better able to manage gingiva than conventional systems. Purpose. The purpose of this in vivo study was to evaluate the gingival management ability of 4 different displacement methods with a standardized subgingival preparation finish line. Material and methods. The effects of 4 displacement techniques on gingival management and impression quality were evaluated by means of 6 evaluation criteria. A subgingival preparation finish line of between 1 and 2 mm was ensured, and the buccal aspects of 252 (n=63) teeth were clinically assessed for ease of application, time spent, bleeding, remnants, and dilatation. The complete reproduction of the preparation finish line and the bubble and void formations on polyether impressions were also evaluated. The data were statistically analyzed with the chi(2) test (alpha=.05). The Bonferroni correction was used to control Type I error for the pairwise comparison groups (alpha=.008). Results. Statistically significant differences were found for all criteria among the groups (P<.05). The nonimpregnated displacement cord group was the least effective group in terms of bleeding and impression quality (P<.008). The aluminum chloride impregnated cord group and the displacement paste with cap group were found to be comparable in terms of remnants, dilatation, and impression quality (P>.008). The retraction cap with paste group showed better results for ease of application, time spent, and bleeding than the aluminum chloride impregnated cord group (P<.008). Although the group with aluminum chloride impregnated cord, displacement paste, and cap showed better results for dilatation, it was time consuming and difficult (P<.008). Conclusions. Except for the nonimpregnated cord group, all of the groups were comparable and clinically useful, with perfect or acceptable impression qualities.
Effect of Adhesive Systems on Microleakage in Endodontically Treated Teeth Restored with Glass Fiber Posts
(2014) Ozdemir, Erdem; Gulsahi, Kamran; Korkmaz, Yonca; Erkut, Selim; Tuncer, Abidin Hakan; https://orcid.org/0000-0003-3510-7265; AAX-5565-2021
The effect of adhesive systems on microleakage in endodontically treated teeth restored with glass fiber posts was studied. Forty carious and crack-free premolars were prepared using a stepback technique and obturated with gutta-percha. The endodontically treated roots were randomly divided into four groups (n = 10). Glass fiber posts cemented following adhesive luting agents; group 1: All Bond 3/Duo Link (ALB/DL), group 2: One-Step Plus/Duo-Link (OSP/DL), group 3: Panavia F 2.0/Panavia ED Primer II (PAN/ED), and group 4: Rely X Unicem (RU). All specimens were thermal cycled and stored in basic fuchsin solution for one week. The roots were sectioned horizontally into three sections: apical, middle, and coronal. The occlusal direction of each section was digitally photographed under a stereomicroscope. Dye penetration area was calculated as the basic fuchsin infiltrated surface divided by total dentin. The data were statistically analyzed using the Mann-Whitney U and Wilcoxon Signed Ranks Tests (alpha = 0.05). The mean area measurements were ranged between 0 and 3.7357. According to the Mann-Whitney U test, there was no significant difference among the groups and sections (p > 0.05). Intragroup comparisons showed a significant difference between coronal-apical and middle-coronal sections in Panavia group (p = 0.043) by Wilcoxon Signed Test. It was found that there was no significant difference among four groups and the apical, coronal, and middle sections. The only difference was found for the group of PAN/ED between coronal-apical and coronal-middle sections.
The Effect of Different Polishing Sequences on the Adhesion of Streptococcus mutans to Feldspathic Porcelain
(2016) Yuzugullu, Bulem; Celik, Cigdem; Ozcelik, Tuncer Burak; Erkut, Selim; Yurdakul, Pinar; Ocal, Yesim; Sener, Burcin; https://orcid.org/0000-0002-5936-0196; AAA-1576-2021
The aim of this research was to determine whether extra-oral surface treatments on feldspathic porcelain surfaces influence initial adhesion of Streptococcus mutans. Ninety-six porcelain specimen discs were fabricated and divided into six equal groups according to surface treatment: fine-grit diamond polishing (Group 1); self-glazing (Group 2); overglazing (Group 3); overglazing followed by a finishing procedure and then overglazing (Group 4); Pearl Surface polishing (Group 5); and Diamond Twist SCLTM polishing (Group 6). Surface roughness and hydrophobicity were assessed. An S. mutans suspension was incubated on each specimen group and evaluated. A one-way analysis of variance, post-hoc Tukey honestly significantly different test, Friedman test, and t-test were used for statistical analysis. Group 1 showed the highest surface roughness (p < 0.001) and bacterial adhesion (p < 0.05). Groups 5 and 6 specimen surfaces presented significantly higher contact angles (p < 0.05). Group 1 had the highest S. mutans adhesion, followed by Groups 3, 5, 6, 2, and 4 (p < 0.05). Reglazing after grinding may therefore decrease bacterial adhesion beneficially.
Effect of Different Surface-Cleaning Techniques on The Bond Strength of Composite Resin Restorations
(2014) Erkut, Selim; Yilmaz, Burak; Bagis, Bora; Kucukemen, Cigdem; Ozdemir, Erdem; Acar, Ozlem; 24939254
Statement of problem. Different techniques have been suggested for cleaning dentin surfaces after the removal of an interim prosthesis and before the application of a bonding agent. How different surface-cleaning techniques affect the bond strength of the composite resin restorations is not clear. Purpose. The purpose of this study was to investigate the effects of different surface-cleaning techniques on the bond strength of composite resin restorations and the surface topography of the prepared tooth surfaces. Material and methods. The occlusal surfaces of 25 molars were ground until the dentin was exposed. A bonding agent and interim cement were applied on the teeth. The teeth were divided into 5 groups (n=5) according to the method used for surface-cleaning (microairborne-particle abrasion, alcohol, rubber-rotary instrument, desiccating agent, and control). Once the surfaces of the teeth had been cleaned, the same bonding material was applied to the teeth. A 5-mm-thick composite resin layer was built up. Each specimen was sectioned to microbars, and 6 centrally located beams were selected for microtensile testing (n=30) (1.10 +/- 0.10 mm). The data were statistically analyzed with 1-way ANOVA (1-sample Kolmogorov-Smirnov test). The Bonferroni test was used for significantly different groups (alpha=.05). One specimen from each group was observed under a scanning electron microscope and an atomic force microscope. Energy dispersive x-ray analysis also was performed. Results. Bond strength values were in the following descending order: microairborne-particle abrasion, desiccating agent, alcohol, rubber-rotary instrument, control. Differences between the microairborne-particle abrasion group and the remainder of the groups, desiccating agent-rubber-rotary instrument, desiccating agent-control, alcohol-rubber-rotary instrument, and alcohol-control groups, were statistically significant (P<.05). The microairborne-particle abrasion group displayed the roughest surface and a different surface topography from the remainder of the groups. Increased aluminum was observed in the microairborne-particle abrasion group. Conclusions. Surface-cleaning techniques, except for the rubber-rotary instrument, increased the bond strength of composite resin. The roughest dentin surfaces and highest bond strength were achieved with the microairborne-particle abrasion technique.
Farklı yüzey işlemlerinin ölçü maddelerinin dentin tübüllerine penetrasyonuna etkisinin incelenmesi
(Başkent Üniversitesi Sağlık Bilimleri Enstitüsü, 2024) Özer, Hasan Yıldırım; Erkut, Selim
Bu in vitro çalışmanın amacı, sabit protetik restorasyon amaçlı ölçü alımı öncesinde diş yüzeyine uygulanan farklı yüzey işlemleriyle; hidrofilik bir ölçü maddesi ve diş yüzeyindeki etkileşimin incelenmesidir. Bu amaçla ölçü alma aşamasında farklı retraksiyon solüsyonu ve immediat dentin sealing (IDS) protokolü etkisi de değerlendirilecektir. Bu işlemler sonrasında ölçü maddelerinin dentin tübüllerine olan penetrasyonu taramalı elektron mikroskopu (SEM) analiziyle incelenip kantitatif olarak gruplar arası karşılaştırmalar yapılacaktır. Çalışmada 60 adet dolgusuz 18-35 yaşlar arasındaki hastalardan çekilmiş molar diş kullanıldı. Dişler, 30.000 devir/dakika (Dentsply Sirona, Amerika) hızında aeratör ile su soğutması altında dişin okluzal minesinden dentin yüzeyine kadar önce büyük grid boyutuna sahip yeşil kuşaklı elmas shoulder frez ile (Lot: 22906) (GZ Instrumente, Avusturya) ardından daha küçük grid boyutuna sahip kırmızı kuşaklı elmas shoulder frez ile (Lot: 14181) (GZ Instrumente, Avusturya) horizontal olarak aşındırıldı. Bu aşındırma işlemi tamamlandığında dentin yüzeyinde düz bir zemin elde edildi. Preparasyonu tamamlanan 60 örnek rastgele 6 gruba ayrıldı (n=10): Grup K: Kontrol grubu, Grup A: AlCl3 grubu (ViscoStat™ Clear %25, Ultradent Products, Amerika), Grup F: Ferrik Sülfat grubu (Astringedent™ X %12.7, Ultradent Products, Amerika), Grup I: IDS grubu (Clearfil Se Bond, KURARAY, Japonya), Grup IA: IDS+ AlCl3 grubu, Grup IF: IDS+Ferrik Sülfat grubu. Yüzey işlemleri tamamlanan dişlere polivinilsiloksan (PVS) (KETTENBACH Panasil İnitial Contact X-Light, Amerika) ölçü materyali enjekte edildi ve daha sonra hafif hava basıncı kullanılarak ölçü yüzeyleri üzerinde hafifçe dağıtıldı. Materyal, üreticinin talimatları izlenerek klinik ortamda olduğu gibi normal şekilde sertleşmeye bırakıldı. Sertleşen ölçü dikkatli bir şekilde diş yüzeyinden ayrıldı. SEM analizi Gaziantep Üniversitesi ULUTEM ve Bilkent Üniversitesi UNAM’da yapıldı. Analizde dentin tübüllerine nüfuz eden ölçü materyali ve yapılan işlemlerin yüzeyde oluşturduğu değişikliklerin görüntülenmesi hedeflendi. Ölçü malzemesi uzantılarının (impression tags) uzunluklarını ve çaplarını belirlemek için SEM görüntüleri üzerinde Öklid analizi ölçümleri yapıldı. Şekil indeksi olarak, düzensiz şekilli nesnelerin bir ölçüsü olarak tanımlanan fraktal analiz kullanıldı. Sayısal değişkenlerin normal dağılıma uygunluğu Shaphiro Wilk testi ile test edilmiştir. Normal dağılan değişkenlerin 6 grupta karşılaştırılmasında ANOVA ve Tukey testi kullanılmıştır. Çalışmamızın sonuçlarına göre IDS uygulaması yapılan gruplarda hidrofilik ölçü maddesinin dentin tübüllerine penetrasyonu IDS uygulaması yapılmayan gruplara göre anlamlı oranda düşük bulunmuştur. Bu çalışma Başkent Üniversitesi Tıp ve Sağlık Bilimleri Araştırma Kurulu tarafından onaylanmış (Proje no: D-DA20/06) ve Başkent Üniversitesi Araştırma Fonunca desteklenmiştir. The aim of this in vitro study is to investigate the interaction between a hydrophilic impression material and the tooth surface with different surface treatments applied to the tooth surface prior to impression taking for fixed prosthetic restoration. For this purpose, the effect of different retraction solutions and immediate dentin sealing (IDS) protocols will also be evaluated during the impression taking phase. After these procedures, the penetration of the impression materials into the dentinal tubules will be examined by scanning electron microscope (SEM) analysis and quantitative comparisons will be made between the groups. In the study, 60 unfilled molars extracted from patients aged 18-35 years were used. The teeth were abraded horizontally from the occlusal enamel of the tooth to the dentin surface under water cooling with an aerator at a speed of 30,000 rpm (Dentsply Sirona, USA), first with a large grid size green-belted diamond shoulder bur (Lot: 22906) (GZ Instrumente, Austria) and then with a smaller grid size red-belted diamond shoulder bur (Lot: 14181) (GZ Instrumente, Austria). When this abrasion was completed, a flat surface was obtained on the dentin surface. The 60 prepared specimens were randomly divided into 6 groups (n=10): Group K: Control group, Group A: AlCl3 group (ViscoStat™ Clear 25%, Ultradent Products, USA), Group F: Ferric sulfate group (Astringedent™ X 12.7%, Ultradent Products, USA), Group I: IDS group (Clearfil Se Bond, KURARAY, Japan), Group IA: IDS+ AlCl3 group, Group IF: IDS+Ferric sulfate group. Polyvinylsiloxane (PVS) (KETTENBACH Panasil Initial Contact X-Light, USA) impression material was injected into the surface treated teeth and then gently distributed over the impression surfaces using light air pressure. The material was allowed to harden normally as in a clinical setting, following the manufacturer's instructions. The hardened impression was carefully removed from the tooth surface. SEM analysis was performed at Gaziantep University ULUTEM and Bilkent University UNAM. The aim of the analysis was to visualize the impression material penetrating the dentinal tubules and the changes on the surface caused by the procedures. Euclidean analysis measurements were performed on SEM images to determine the lengths and diameters of impression tags. Fractal analysis, defined as a measure of irregularly shaped objects, was used as a shape index. The conformity of numerical variables to normal distribution was tested by Shaphiro Wilk test. ANOVA and Tukey test were used to compare normally distributed variables in 6 groups. According to the results of our study, the penetration of the hydrophilic impression material into the dentinal tubules was found to be significantly lower in the groups with IDS application compared to the groups without IDS application. This study was approved by Baskent Üniversity Institutional Review Board (Project no: DDA20/ 06) and supported by Baskent University Research Fund.
The influence of zirconia coping designs on maximum principal stress distribution in all-ceramic premolar crowns: A finite element analysis
(2019) Diker, Burcu; Erkut, Selim; 31675195
Purpose: To evaluate the effects of different coping designs on maximum principal stresses in the veneering material using a finite element analysis method. Methods: A maxillary first premolar tooth model was prepared. The primary and prepared tooth model were scanned with a 3D (three dimensional) scanner. Four different coping and veneer models were designed with 3D computer-aided design software: conventional design (DC); design with 3 mm palatal shoulder (DP); design with 1 mm buccal shoulder and 3 mm palatal shoulder (DB); and design with buccal facet (DF). After the models were designed, they were transferred to the finite element analysis (FEA) software for analyses. The middle points of the buccal, mesial, distal and palatal surfaces were determined in the cervical region. For all models, the maximum principal stress distributions and values of porcelain veneer were evaluated under centric occlusion loading and laterotrusive loading conditions with a FEA. Results: The maximum principal stress area decreased gradually from model DC to model DB on the buccal cervical region under centric occlusion loading. However, models DF and DP showed similar stress distribution. The maximum principal stress at the distal point decreased from DC (14.7 MPa) to DP (13.5 MPa) and DB (9.6 MPa), whereas increased in model DF (33 MPa). Under laterotrusive loading, both the palatal maximum principal stress area and the stress value at the palatal point (model DC: 13.1 MPa, model DP: 3 MPa, model DB: 4MPa) decreased with the palatal shoulder.