The effect of glazing and aging on the surface properties of CAD/CAM resin blocks

Tekce, Neslihan,Fidan, Sinan,Tuncer, Safa,Kara, Dilan,Demirci, Mustafa The Korean Academy of Prosthodonitics 2018 The Journal of Advanced Prosthodontics Vol.10 No.1

PURPOSE. To investigate the effect of accelerated aging on surface properties of glazed CAD/CAM resin blocks using a 2D surface profilometer and a 3D non-contact optical profilometer. MATERIALS AND METHODS. Three types of CAD/CAM resin restorative materials, LAVA Ultimate (3M ESPE, St Paul, MN, USA), VITA Enamic (Vita Zahnfabrik H. Rauter, Bad $S\ddot{a}ckingen$, Germany), and Cerasmart (GC Corparation, Tokyo, Japan) were used for this study. CAD/CAM blocks were cut in 3-mm thickness slabs and divided into three groups; Group 1: control group (specimens polished with 600 grit SCI paper); Group 2: specimens sandblasted, silanized, and glazed with Optiglaze Color (GC); Group 3: glazed specimens subjected to 5000 thermocycles (n=15). The surface roughness ($R_a$ and $R_z$) was evaluated using a profilometer and a 3D scanning instrument. Data were analyzed using two-way ANOVA and Tukey's post- hoc test (P<.05). RESULTS. LAVA, VITA, and Cerasmart exhibited statistically similar $R_a$ and $R_z$ values for each group (P>.05). For VITA and Cerasmart, the specimens in Group 1 exhibited significantly higher $R_a$ values than Group 2 (P<.05). Group 1 ($0.502R_a$), Group 2 ($0.384R_a$), and Group 3 ($0.431R_a$) exhibited statistically similar $R_a$ values for LAVA (P=.062). After 5000 thermocycles, surface roughness values did not change significantly for glazed LAVA, VITA, and Cerasmart (P>.05). CONCLUSION. Glaze material Optiglaze Color makes CAD/CAM resin surfaces smooth and glazed CAD/CAM surfaces seem resistant to deterioration under 5000 thermocycles.

The effect of different drinks on the color stability of different restorative materials after one month

Tekce, Neslihan,Tuncer, Safa,Demirci, Mustafa,Serim, Merve Efe,Baydemir, Canan The Korean Academy of Conservative Dentistry 2015 Restorative Dentistry & Endodontics Vol.40 No.4

Objectives: The aim of this study was to evaluate the effect of three different drinks on the color parameters of four different restorative materials. Materials and Methods: Three different composites (Filtek Ultimate Universal Restorative, Filtek Ultimate Flowable, and Filtek Silorane, 3M ESPE) and a polyacid-modified composite resin material (Dyract XP, Dentsply DeTrey GmbH) were evaluated. Eighty-four disc-shaped specimens of 8 mm in diameter and 2 mm in thickness were prepared (n = 21 each). Color coordinates ($L^*a^*b^*$, ${\Delta}L^*$, ${\Delta}a^*$, ${\Delta}b^*$, and ${\Delta}E^*$) were measured using a $V{\dot{I}}TA$ Easyshade Compact ($V{\dot{I}}TA$ Zahnfabrik) after 24 hr of storage (baseline) and after 30 day of storage in three different beverages of black tea, Coca cola, or water (control) (n = 7). In each beverage, the specimens were stored three times a day, one hr each, for 30 day. The color changes (${\Delta}E$) were calculated and were analyzed by Kruskal-Wallis and Dunn multiple comparison test. Results: The color difference (${\Delta}E^*$) of the resin materials ranged between 1.31 and 15.28 after 30 day of immersion in the staining solutions. Dyract XP in Coca cola ($15.28{\pm}2.61$) and black tea ($12.22{\pm}2.73$) showed the highest mean ${\Delta}E^*$ value after 30 day, followed by Filtek Ultimate Universal Restorative ($5.99{\pm}1.25$) and Filtek Ultimate Flowable ($4.71{\pm}1.40$) in black tea (p < 0.05). Conclusions: The compomers displayed unacceptable color changes at the end of 30 day in all beverages. Among resin composites, the silorane based composite exhibited relatively good color stability than the others. Filtek Ultimate Universal Restorative and Filtek Flowable showed similar color changes in all beverages.

Identification of royal jelly as a potential new drug to protect the ovarian reserve and uterus against cyclophosphamide in rats

Mehmet Bulbul,Ali Tekce,Ebru Annac,Omer Korkmaz,Muhittin Onderci,Deniz Korkmaz,Akin Mustafa Demirci The Korean Society for Reproductive Medicine 2023 Clinical and Experimental Reproductive Medicine Vol.50 No.1

Objective: The aim of this study was to investigate the effect of royal jelly (RJ), a powerful natural antioxidant, on cyclophosphamide-induced ovarian damage. Methods: Thirty-two Wistar albino rats were divided into four groups. Oral treatment was administered to all rats for 16 days after a single intraperitoneal injection. The control group received intraperitoneal and oral saline; the RJ group received intraperitoneal saline and 100 mg/kg/day oral RJ; the cyclophosphamide group received intraperitoneal 100 mg/kg cyclophosphamide and oral saline; and the treatment group received intraperitoneal 100 mg/kg cyclophosphamide and 100 mg/kg/day oral RJ. The groups were compared in terms of ovarian reserve tests and histopathological changes in the ovary and uterus. Results: All follicle counts were higher in the treatment group than in the cyclophosphamide group. The increase in the number of preantral follicles (p=0.001) and the decrease in the number of atretic follicles (p=0.004) were statistically significant. RJ treatment significantly improved follicular degeneration and cortical fibrosis in the ovary and epithelial and gland degeneration in the uterus due to cyclophosphamide toxicity. Conclusion: According to these results, RJ reduces cyclophosphamide-related ovarian and endometrial damage in rats. For this reason, it should be further investigated to determine its effects on reproductive function.

Bilateral Trade Flows in the Gulf Cooperation Council Countries: What happend to the Middle East Integration after 2003?

( Aysu Insel ),( Mahmut Tekce ) 세종대학교 경제통합연구소(구 세종대학교 국제경제연구소) 2011 Journal of Economic Integration Vol.26 No.2

It is well known that the GCC countries are heavily dependent on oil and hydrocarbon industries, but during the 2003-2008 period, economic diversification is proceeded; enhancing the role of the private sector, encouraging FDI, and laying the ground for competitive integration in the globalization process. The year 2003 is special for the economic integration within the GCC due to the introduction of the custom union and high growth. This paper analzes the trade flows of the GCC countries before and after the signature of the Custom Union agreement in 2003. Fixed effects panel models have been estimated using the LS and GMM methods. It has been found that the year 2003 is special for the GCC countries. The year 2003 indicates the turning points in the intra-GCC trade and also in the GCC trade with the rest of the world. The results show that the 2003 Custom Union agreement has not fostered the intra-GCC trade, except for the United Arab Emirates, and also that the order of top fifteen trade partners has changed significantly from the EU countries and the US to the Asian countries after 2003. Additionally, the exports and imports of the GCC countries are related to the wealth of partner countries, but not distance. These results have important implications for the economic, cultural and political issues in trade negotiations to provide any trade incentive for the GCC countries.

Microhybrid versus nanofill composite in combination with a three step etch and rinse adhesive in occlusal cavities: five year results

Tuncer, Safa,Demirci, Mustafa,Oztas, Evren,Tekce, Neslihan,Uysal, Omer The Korean Academy of Conservative Dentistry 2017 Restorative Dentistry & Endodontics Vol.42 No.4

Objectives: The aim of the study was to evaluate the 5-year clinical performance of occlusal carious restorations using nanofill and microhybrid composites, in combination with 3-step etch-and-rinse adhesives, in patients who were going to commence orthodontic treatment. Materials and Methods: A total of 118 restorations for occlusal caries were conducted prior to orthodontic treatment. Occlusal restorations were performed both with Filtek Supreme XT (3M ESPE) and Filtek Z250 (3M ESPE) before beginning orthodontic treatment with fixed orthodontic bands. Restorations were clinically evaluated at baseline and at 1, 2, 3, 4, and 5-year recalls. Results: None of the microhybrid (Filtek Z250) and nanofill (Filtek Supreme XT) composite restorations was clinically unacceptable with respect to color match, marginal discoloration, wear or loss of anatomical form, recurrent caries, marginal adaptation, or surface texture. A 100% success rate was recorded for both composite materials. There were no statistically significant differences in any of the clinical evaluation criteria between Filtek Z250 and Filtek Supreme XT restorations for each evaluation period. Conclusions: The composite restorations showed promising clinical results relating to color matching, marginal discoloration, wear or loss of anatomical form, recurrent caries, marginal adaptation, and surface texture at the end of the 5-year evaluation period.

Cytotoxic effects of different self-adhesive resin cements: Cell viability and induction of apoptosis

Sismanoglu, Soner,Demirci, Mustafa,Schweikl, Helmut,Ozen-Eroglu, Gunes,Cetin-Aktas, Esin,Kuruca, Serap,Tuncer, Safa,Tekce, Neslihan The Korean Academy of Prosthodonitics 2020 The Journal of Advanced Prosthodontics Vol.12 No.2

PURPOSE. The effects of four different self-adhesive resin cement materials on cell viability and apoptosis after direct and indirect exposure were evaluated using different cell culture techniques. MATERIALS AND METHODS. Self-adhesive cements were applied to NIH/3T3 mouse fibroblasts by the extract test method, cell culture inserts, and dentin barrier test method. After exposure periods of 24 h and 72 h, the cytotoxicity of these self-adhesive materials was evaluated using the MTT assay (viability) and the Annexin-V-FITC/PI staining (apoptosis). RESULTS. The lowest cell viability was found in cells exposed to BeautiCem SA for 24 h in the extract test method. Cell viability was reduced to 70.6% compared to negative controls. After the 72 h exposure period, viability rate of cell cultures exposed to BeautiCem SA decreased more than 2- fold (29.5%) while cells exposed to RelyX U200 showed the highest viability rate of 71.4%. In the dentin barrier test method, BeautiCem SA induced the highest number of cells in apoptosis after a 24 h exposure (4.1%). Panavia SA Cement Plus was the material that caused the lowest number of cells in apoptosis (1.5%). CONCLUSION. The used self-adhesive cements have showed different cytotoxic effects based on the evaluation method. As exposure time increased, the materials showed more cytotoxic and apoptotic effects. BeautiCem SA caused significantly more severe cytotoxic and apoptotic effects than other cements tested. Moreover, cements other than BeautiCem SA have caused necrotic cell death rather than apoptotic cell death.