https://hdl.handle.net/20.500.12809/173 2026-04-08T23:33:43Z https://hdl.handle.net/20.500.12809/10607 Effects of different storage media on dentin moisture, microhardness, and bond strength of resin composite Yılmaz, Fatma; Guvenç, P.; Pamir, T.; Demirbaş, A.; Şen, B. H. Background: In in vitro studies, it is desirable that the storage solutions in which dental samples kept between extraction and experiment should prevent dehydration and have antimicrobial properties. However, it should be taken into consideration that these solutions may have some effects that directly change test results on physical and mechanical properties of laboratory samples. Aims: The aim of this in vitro study was to evaluate the effects of different storage media on dentin moisture, microhardness, and microshear bond strength of resin composite to dentin. Thirty non-carious human premolars were randomly divided into three groups: 1. 0.1% Thymol (T), 2. Distilled water (DW), 3. Dry storage (DS) (control) (n = 10). Dentin moisture was measured with a digital grain moisture meter. Dentin microhardness was measured with the Vickers test. The bond strength was measured with a microshear test. Materials and Methods: Analysis of variance (ANOVA) followed by the Bonferroni test was used for statistical evaluation (p = 0.05). Results: Dentin moisture of the experimental groups was statistically higher than that of the control group (p < 0.05). In addition, the dentin moisture of group DW was significantly higher than that of group T (p < 0.05). The mean microshear bond strength of resin composite to dentin was higher in group DW than in group T and group DS (p < 0.05), while there was no statistical difference between group T and group DS. The microhardness values of all groups were statistically similar. Conclusions: Storage solutions used for disinfection and to prevent dehydration may have negative effects on dentin moisture and bond strength. 2023-01-01T00:00:00Z https://hdl.handle.net/20.500.12809/10497 Dental Pulp Inflammation Initiates the Occurrence of Mast Cells Expressing the α1 and β1 Subunits of Soluble Guanylyl Cyclase Korkmaz, Yüksel; Plomann, Markus; Puladi, Behrus; Demirbaş, Ayşegül; Bloch, Wilhelm The binding of nitric oxide (NO) to heme in the β1 subunit of soluble guanylyl cyclase (sGC) activates both the heterodimeric α1β1 and α2β1 isoforms of the enzyme, leading to the increased production of cGMP from GTP. In cultured human mast cells, exogenous NO is able to inhibit mast cell degranulation via NO-cGMP signaling. However, under inflammatory oxidative or nitrosative stress, sGC becomes insensitive to NO. The occurrence of mast cells in healthy and inflamed human tissues and the in vivo expression of the α1 and β1 subunits of sGC in human mast cells during inflammation remain largely unresolved and were investigated here. Using peroxidase and double immunohistochemical incubations, no mast cells were found in healthy dental pulp, whereas the inflammation of dental pulp initiated the occurrence of several mast cells expressing the α1 and β1 subunits of sGC. Since inflammation-induced oxidative and nitrosative stress oxidizes Fe2+ to Fe3+ in the β1 subunit of sGC, leading to the desensitization of sGC to NO, we hypothesize that the NO- and heme-independent pharmacological activation of sGC in mast cells may be considered as a regulatory strategy for mast cell functions in inflamed human dental pulp. 2023-01-01T00:00:00Z https://hdl.handle.net/20.500.12809/10288 Diş çürüğü deneyimi ve periodontal durum arasındaki ilişkinin değerlendirilmesi Demirbaş, Ayşegül; Yılmaz, Fatma Amaç: Bu çalışmada çürük ve periodontal hastalığa sebep olan etiyolojik faktörler incelenerek; çürük deneyimi ile periodontal durum arasındaki ilişkinin değerlendirilmesi amaçlanmıştır. Yöntemler: Çalışmada gönüllü katılan 103 hastanın (20-69 yaş) sosyodemografik özellikleri, sistemik sağlık durumları, yeme alışkanlıkları, diş bakım rutinleri ile ağız-diş problemlerine ilişkin verileri toplandı. Hastala- rın çürük deneyimi diş çürüğü indeksleri (DMFT) ile; periodontal durumları toplum periodontal durum indeksi (CPI), dişlerdeki eklenti miktarını ölçen Quikley-Hein ve Turesky plak indeksi (TQHPI) ve dişeti enflamasyonunu ölçen gingival indeks (GI) ile belirlendi. Çürük deneyimi ve periodontal durumla ilişkili olabilecek faktörlerin etkisi Mann-Whitney U ve Kruskal Wallis testi ile değerlendirildi. Diş çürüğü ile periodontal durum indeksleri arasındaki ilişkinin değerlendirilmesinde Spearman Korelasyon testi uygulandı. Bulgular: 20-29 yaş grubunda DMFT ortalaması 8,62, CPI değerleri ortalaması 1,69 iken; 50-59 yaş grubunda DMFT ortalaması 13,24, CPI değerleri ortalaması 2,1 olarak tespit edildi. Katılımcıların yaş dağılımları ve diş fırçalama sıklığının hem DMFT indeksi, hem de CPI değerlerini anlamlı derecede etkilediği tespit edildi (P < ,05). Eğitim durumuyla CPI değerleri arasında anlamlı bir ilişki bulundu (P < ,05). Ancak DMFT indeksi ile CPI, TQHPI ve GI değişkenleri arasında anlamlı bir korelasyon bulunmadı. Sonuç: Diş çürüğü ve periodontal hastalıklar düzensiz ağız bakım alışkanlıkları ve kötü ağız hijyeni gibi ortak etiyolojik faktörlere sahip gibi görünse de, temel risk faktörleri farklıdır. Tüm bireyler için bu hastalıklara sebep olan tek bir değişkenden bahsetmek doğru değildir. Konu ile ilgili daha kapsamlı epidemiyolojik çalışmalara ihtiyaç vardır; Objective: In this study, it was aimed to evaluate the relationship between caries experience and periodontal status by examining the etiological factors causing caries and periodontal disease. Methods: In this study, the data on sociodemographic characteristics, systemic health conditions, eating habits, dental care routines, and oral and dental problems of the 103 voluntary patients (ages 20-69) were collected. The caries experience of the patients was measured with the dental caries indices (DMFT). In order to evaluate their periodontal status, measurements were made with the community periodontal status index (CPI); the Quikley-Hein and Turesky plaque index (TQHPI), which measures the amount of attachment in the teeth; and the gingival index (GI) that measures gingival inflammation. The effect of factors that may be related to the caries experience and periodontal status were evaluated using the Mann-Whitney U and Kruskal Wallis test. Spearman Correlation test was used to evaluate the relationship among DMFT indices and periodontal status indexes. Results: While the mean DMFT value is 8.62 and the mean CPI value is 1.69 in 20-29 ages-group; in 50-59 ages-group, the mean DMFT value was 13.24, and the mean CPI value was 2.1. It was determined that the age distribution and the frequency of tooth brushing of the participants affected both DMFT and CPI values signifi- cantly (P < .05). A significant correlation was found between education status and CPI values (P < .05). However, there was no significant correlation between DMFT indices and CPI, TQHPI and GI variables. Conclusion: Although tooth decay and periodontal diseases seem to have common etiological factors such as irregular oral care habits and poor oral hygiene, the major risk factors are different and it is not correct to mention a single variable that causes these diseases for all individuals. More comprehensive epidemiological studies are needed on the subject. 2022-01-01T00:00:00Z https://hdl.handle.net/20.500.12809/10005 Effects of different universal adhesives and surface treatments on repair bond strength between resin composites Yılmaz, Fatma; Yazkan, Başak; Hergüner, Şeyda Objective This study aimed to evaluate the effects of different universal adhesives and surface treatments on the repair bond strength between resin composites. Materials and Methods A total of 220 composite samples were divided into three groups according to the adhesive resin to be applied: 1) Scotchbond Universal, 2) G-Premio Bond, and 3) Peak Universal Bond. They were then divided into seven subgroups according to surface treatments (n = 10): A) air abrasion, B) air abrasion+silane, C) hydrofluoric acid, D) hydrofluoric acid+silane, E) air abrasion+hydrofluoric acid+silane, F) silane, and G) no surface treatment (negative control). After surface treatment, a repair composite was applied. Samples aged in the thermocycle were subjected to micro-tensile bond strength testing. Cohesive strength values of 10 non-aged composite blocks were used as a positive control. Kruskal-Wallis and one-way ANOVA tests were used for statistical evaluation. Fractured surfaces were evaluated using a scanning electron microscope. Results In Scotchbond Universal and G-Premio Bond, the mean micro-tensile bond strength value of the no surface treatment subgroup was significantly lower than that of the positive control. All subgroups of Peak Universal Bond showed similar values to the positive control. Conclusion While Scotchbond Universal and G-Premio Bond required mechanical roughening before adhesive application, Peak Universal Bond did not require any surface treatment. Clinical Significance Different universal adhesives may show different repair bonding strengths with different surface treatments. Since achieving a standard in this regard can be associated with many independent factors, clinicians should determine how to apply the adhesive they use most effectively with the most appropriate surface treatment based on their own clinical experience. 2022-01-01T00:00:00Z