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    Antibacterial effect of dental cements evaluated using agar diffusion test
    (TAYLOR & FRANCIS LTD, 2015) Dundar, Ayse; Karacam, Nejla; Yavuz, Tevfik; Ozturk, Nilgun; Pinarkara, Yasemin
    Purpose: Secondary caries can occur around the restoration, fixed prosthesis, and orthodontic band margins because of cariogenic bacteria. Long-lasting antibacterial effectiveness of dental cements used contemporarily can reduce this phenomenon. The purpose of this study was to examine the antibacterial activities of nine dental cements (BisCem((R)), Super-Bond C&B, Rely X-TM, Panavia(TM) F 2.0, Variolink((R)) II, Unitek(TM) Multi Cure, Multilink((R)) Automix, Clearfil(TM) Esthetic Cement, Transbond(TM) LR) using agar diffusion test. Materials and methods: The test materials were inserted into the wells of Muller Hinton agar plates inoculated with Streptococcus mutans and Streptococcus salivarious. The diameters of the inhibition zones produced around the materials were measured after 24h of incubation. Two-Way ANOVA, the Kruskal-Wallis, and the Mann-Whitney U tests at a significance level of pResults: Unitek Multi Cure cement exhibited a significant difference from the control group against both S. mutans and S. salivarious (p<0.05). While the zone of inhibition of Unitek Multi Cure cement was shorter (8.50 +/- 1.77) than the control group (12.63 +/- 1.30), Unitek Multi Cure had antibacterial effect against S. mutans and S. salivarious (p<0.05). S. mutans displayed a significantly lower resistance to Unitek Multi Cure, BisCem, and Superbond C&B than S. salivarious (p<0.05). Conclusion: Conventional glass ionomer cement, Unitek Multi Cure, exhibited greatest in vitro antibacterial activity against both S. mutans and S. salivarious. Formation of dental caries had been suppressed by the fluoride-releasing GICs.
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    Comparative effects of denture cleansers on physical properties of polyamide and polymethyl methacrylate base polymers
    (JAPANESE SOC DENTAL MATERIALS DEVICES, 2013) Durkan, Rukiye; Ayaz, Elif Aydogan; Bagis, Bora; Gurbuz, Ayhan; Ozturk, Nilgun; Korkmaz, Fatih Mehmet
    The purpose of this study was to evaluate the effect of denture cleansers on the surface roughness, hardness and color stability of two polyamides (Valpast, Deflex), a butadiene styrene copolymer PMMA (Rodex), and PMMA polymer as a control group (Paladent). Each material was divided into 5 sub-groups (n=7) as two control and three test groups. Three test groups were immersed for 20 days in commercially available three denture cleansers (CO-Corega, PR-Protefix, VA-Valclean). Two-way analysis of variance and Tukey's post hoc HSD test were used to evaluate surface roughness and hardness data (alpha=0.05). Delta E, Delta L*, Delta a* and Delta b* mean values were used for ANOVA, Tamhane test was used as post hoc. Polyamides showed low hardness and high roughness before and after immersion. A significant decrease in hardness was observed for all resins except Rodex after immersion (p<0.05). The denture cleansers changed the roughness, hardness and color of some resins.
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    Effects of storage solutions on mineral contents of dentin
    (ELSEVIER TAIWAN, 2011) Secilmis, Asli; Dilber, Erhan; Gokmen, Fatma; Ozturk, Nilgun; Telatar, Tuba
    Background/purpose: It is important to understand how storage conditions affect the tooth structure for in vitro studies. There is little information regarding the selection of an appropriate storage solution. This study was conducted to determine the influence of storage solutions on the mineral contents of dentin. Materials and methods: Ninety dentin specimens were obtained from 30 molar teeth. Specimens were divided into two groups of 45 each (storage for 45 and 90 days). Each of the two groups was further divided into nine storage solution groups (n = 5). For the control group, freezing was used to store the teeth. The mean percentage weights of calcium, potassium, sodium, and phosphorus in each dentin slab were measured by inductively coupled plasma-atomic emission spectrometry. Two-way analysis of variance and Tukey's honest significant difference test were used to analyze the data (P = 0.05). Results: There were significant differences in calcium among groups. The potassium level of slabs stored in artificial saliva and the sodium level of slabs stored in buffered solutions and saline solution increased (P < 0.05). Potassium, sodium, and phosphorus levels were highest when stored for 45 days (P < 0.05). Conclusion: The storage solution and storage time affected the compositional structure of dentin. The results suggest that storage processes may influence outcomes of in vitro dental research. Copyright (C) 2011, Association for Dental Sciences of the Republic of China. Published by Elsevier Taiwan LLC. All rights reserved.
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    In vivo heat transfer capacities of autopolymerizing, heat-polymerizing, and injection-molded acrylic resins
    (QUINTESSENCE PUBLISHING CO INC, 2006) Oruc, Selcuk; Usumez, Aslihan; Enhos, Dilek Simsek; Ozturk, Nilgun
    The aim of this pilot study was to measure the heat transfer capacities of heat-polymerizing, injection-molded, and auto polymerizing acrylic resins in vivo. Two volunteers used acrylic resin removable plates and consumed hot (69 degrees C) and cold drinks (6 degrees C). Differences between oral temperature and highest and lowest temperature readings were recorded. Temperature changes for the autopolymerizing acrylic resin were found to be significantly higher than the heat-polymerizing and injection-molded acrylic resins for both cold and hot drinks. Despite the disadvantages of auto polymerizing acrylic resins, their high heat transfer capacity may be an advantage.
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    Phytochemical contents and enzyme inhibitory and antioxidant properties of Anethum graveolens L. (dill) samples cultivated under organic and conventional agricultural conditions
    (PERGAMON-ELSEVIER SCIENCE LTD, 2013) Orhan, Ilkay Erdogan; Senol, F. Sezer; Ozturk, Nilgun; Celik, Sadiye Ayse; Pulur, Aysen; Kan, Yuksel
    Inhibitory effect of the n-hexane, dichloromethane, ethyl acetate, and ethanol extracts from Anethum graveolens L. (dill) cultivated under organic (AG-O) and conventional (AG-C) conditions was tested against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and tyrosinase at 200 mu g mL(-1). Their antioxidant activity was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), N,N-dimethyl-p-phenylendiamine (DMPD), and nitric oxide (NO) radical scavenging assays as well as ferric ion-chelation capacity, ferric-(FRAP), and phosphomolybdenum-reducing antioxidant power (PRAP). The phytochemical analyses have been performed on both of the plant samples. GC-MS analysis pointed out that alpha-phellandrene was the main component in both of the essential oils in varying amounts (47.75% for AG-O and 27.94% for AG-C), while oleic acid was the dominant in the fruit oils of two samples (36.39% for AG-O and 53.87% for AG-C). HPLC analysis showed that both of the extracts contained rosmarinic acid as the major phenolic acid. The extracts inhibited BChE at moderate level, while the ethanol extracts exerted remarkable NO scavenging effect. The results emphasize that cultivation conditions may have effect on bioactivity and phytochemical content on plant samples. (c) 2013 Elsevier Ltd. All rights reserved.
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    Push-out bonding strengths of four different dowel systems luted with two different adhesive systems
    (TAYLOR & FRANCIS LTD, 2014) Orucoglu, Hasan; Yavuz, Tevfik; Demir, Necla; Ozturk, Nilgun; Ozturk, Bora
    This in vitro study investigates the bonding capacity of resin cements to dowels, using the push-out bonding strength of four different dowel systems, namely, stainless steel dowels (SSD), resin-supported polyethylene fiber dowels (RSPFD), zirconia dowels (ZD), and superpost glass fiber dowels (GFD), luted in root canals, using two different resin cements, namely, Multilink Automix Cement and Clearfil Esthetic Cement. Ninety-six maxillary central incisor teeth were sectioned below the cementoenamel junction, and the roots were treated endodontically. Then the roots were placed into four groups, based on the dowel systems used. The roots were further placed into two subgroups, based on the cement type used as subgroup A and subgroup B. Push-out bonding tests were performed on the bonded specimens, which were cut into 1mm thick sections. A two-way ANOVA test and Tukey's HSD tests were performed. The push-out bonding strength values for SSD, ZD, and RSPFD were not significantly different (p>0.05). The means for GFD were significantly higher than the means for ZD (p<0.05) when Multilink Automix Cement was used. However, when Clearfil Esthetic Cement was used, the means for RSPFD were significantly higher (p<0.001) than the means for the other systems. When Clearfil Esthetic Cement was used, the RSPF dowel system provided significantly higher bonding strength values than the other systems.