Browsing by Author "Ozcan, Mutlu"

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The Erosion Kinetics of Conventional and Resin-Modified Glass-Ionomer Luting Cements in Acidic Buffer Solutions
(Japanese Soc dental Materials devices, 2012) Hazar-Yoruc, Binnaz; Bavbek, Andac Barkin; Ozcan, Mutlu
This study investigated the erosion kinetics of conventional and resin-modified glass-ionomer luting cements in acidic buffer solutions as a function of time. Disc shaped specimens were prepared from conventional (Ketac-Cem: KTC) and resin-modified glass ionomer cements (Fuji Plus: FP) and immersed in three acidic buffer solutions (0.01 M) namely, acetic acid/sodium acetate (AA), lactic acid/sodium lactate (LAB) and citric acid/sodium citrate (CAB) with a constant pH of 4.1 and stored for 1, 8, 24, 48, 80, 120 and 168 h. F concentration was determined using ion-specific electrode. Si, Ca and Al concentrations were determined by atomic absorption spectroscopy. Ca, Al, Si and F solubility rates in both FP and KTC were the highest in CAB solution. The erosion rates of both FP and KTC in all buffer solutions increased as a function of immersion time. The amount of F eluted from FP was more than that of KTC. The total amount of elements released from FP was less than KTC in all solutions.
Evaluation of the Effectiveness of Current Disinfection Methods in Complete Denture Patients
(Quintessence Publishing Co inc, 2022) Degirmenci, Beyza Unalan; Kakai, Ribaz Tahsin Hayas; Guducuoglu, Huseyin; Ozcan, Mutlu
Objectives: Candida adherence to the denture base is an important cause of denture stomatitis in elderly and handicapped patients where effective patient-and physician-based disinfection methods are required. The purpose of this study was to investigate the in vivo effectiveness of chemical and physicochemical methods and their combinations against common oral Candida species on denture base acrylic resin. Method and materials: Patients were divided into six groups according to disinfection methods. For chemical disinfection, chlorhexidine, sodium hypochlorite, and glutaraldehyde were used by the patients. Microwave and ozone therapy were applied by physicians for physicochemical disinfection. Fungal load count was performed. This procedure was repeated before applying any disinfection procedures, at 1 week and 1 month after the patient started to use the relevant chemical disinfectant and ap ply physicochemical methods. A multivariate analysis test was used to determine the change in fungal load over time and whether this change led to a difference among the groups (P < .05). Results: The most frequently isolated Candida strain was Candida albicans. The change in fungal load over time was significantly different (P < .001). However, the difference between the groups did not show any significant difference in the paired comparison analyses of the chemical disinfection groups (P>.05). No Candida strains were detected in either physicochemical method at any of the control time points. Conclusions:The study concluded that chemical disinfectants used by patients were effective for but total eradication of Candida adhesion requires the use of additional ozone or microwave therapy.
Influence of Powdered Dentin on the Shear Bond Strength of Dentin Bonding Systems
(Japanese Soc dental Materials devices, 2012) Eliguzeloglu Dalkilic, Evrim; Genc, Ozgur; Ozcopur, Betul; Belli, Sema; Eskitascioglu, Gurcan; Ozcan, Mutlu
This study evaluated the effect of different amounts of dentin powder (DP) mixed in Clearfil SE Bond (CSB) or Single Bond (SB) on adhesion to dentin. Human third molars (n=96) were sectioned to expose the mid-coronal dentin and divided into eight experimental groups (n=12 per group), namely, Group 1: CSB, Group 2: CSB+1.5 mg DP, Group 3: CSB+3 mg DP, Group 4: CSB+4.5 mg DP, Group 5: SB, Group 6: SB+1.5 mg DP, Group 7: SB+3 mg DP, and Group 8: SB+4.5 mg DP. Filtek Z250 composite was bonded onto dentin, and all specimens were subjected to shear bond strength test at a crosshead speed of 1 mm/min. Highest bond strength was obtained in Groups 1, 2, and 3 (15.1, 13.5, and 16.4 MPa respectively; p>0.05) and the lowest in Groups 6, 7, and 8 (5.5, 5.6, 4 MPa; p>0.05). DP addition, regardless of amount, adversely affected the bond strength of SB. Bond strength of CSB was not affected when 1.5 or 3 rag of DP was added.
Lipid Peroxidation and Dna Oxidation Caused by Dental Filling Materials
(Elsevier Taiwan, 2017) Yildiz, Mehmet; Alp, Hamit Hakan; Gul, Pinar; Bakan, Nuri; Ozcan, Mutlu
Background/purpose: The two direct dental restorative materials most commonly used today are silver-mercury amalgam and resin-based composites. The purpose of this study was to examine the effects of these two restorative materials and substances released by these into the oral environment on lipid peroxidation and DNA oxidation after entering the blood circulation. Materials and methods: Blood samples from 41 patients were collected before and 24 hours after the application of these restorative materials. The 8-hydroxydeoxyguanosine/deoxyguanosine ratio in these samples was measured to determine oxidative DNA damage, and malondialdehyde levels were measured to define lipid peroxidation. The paired samples t test and Pearson correlation analysis were used for the analysis of variables (alpha = 0.05). Results: While no statistically significant difference was observed after amalgam filling application in terms of DNA oxidation, a significant difference was observed after composite application (P < 0.05). Furthermore, a significant increase was determined in malondialdehyde levels of two materials (P < 0.05). In both amalgam and composite applications, a significant difference was observed before and after application in terms of released substances (mercury and unpolymerized monomer, respectively, P < 0.001). Conclusion: Mercury increased lipid peroxidation and Bis-GMA and TEGDMA dental resins increased both lipid peroxidation and DNA oxidation markers. (C) 2017 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V.
Micro-Shear Bond Strength of Adhesive Resins To Enamel at Different Relative Humidity Conditions
(Japanese Soc dental Materials devices, 2013) Bavbek, Andac Barkin; Demir, Erhan; Goktas, Baris; Ozcopur, Betul; Behram, Benin; Eskitascioglu, Gurcan; Ozcan, Mutlu
This study tested whether exhaled humid conditions would affect the adhesion of etch-and-rinse, two-step and one-step self-etch adhesive resins to enamel. Enamel surfaces of human maxillary anterior teeth (N=240, n=20) were exposed to four humid conditions (H1: 63-68%, H2: 73-78%, H3: 93-98%, H4: 36-45% RH) during bonding with Adper Single Bond 2 (SB2), Clearfil SE Bond (CSE) and Adper Easy Bond (AEB). Specimens were stored in distilled water at 37 degrees C for 24 h and tested to failure using micro-shear bond strength (mu SBS) test. Data were analyzed using two-way ANOVA and Tukey's test (p<0.05). The mu SBS to enamel with SB2, CSE and AEB was not significantly affected by humidity parameters. AEB resulted in significantly lower mu SBS in all conditions. The frequency of adhesive failures was the highest at H2, H3 for SB2, H3 for CSE and H1-4 for AEB indicating that humidity conditions may decrease adhesion quality to enamel.
Monomer Release From Bulk-Fill Composite Resins in Different Curing Protocols
(Nihon Univ, School dentistry, 2020) Gul, Pinar; Alp, Hamit H.; Ozcan, Mutlu
The purpose of this study was to determine the depth of cure and the type and amount of monomers released from bulk-fill composites in different curing protocols. Five different composite resins Filtek Bulk-Fill Posterior, Filtek Bulk-Fill Flowable, SureFil SDR, X-tra Fil, and X-tra base. were used. A light-emitting diode (LED) device was used in 3 different modes (standard, high power, and extra power mode), and a halogen light device was also used as a control. Surface hardness was measured and the depth of cure was calculated. Monomer analysis was performed using high performance liquid chromatography (HPLC). The data were analyzed using Tamhane's T2 post-hoc test (alpha = 0.05). The cure depth for all materials except for Filtek Bulk-Fill Posterior (extra power mode) and Filtek Bulk-Fill Flowable (high power and extra power modes) was over 80%. Under the conditions of this study, the amount of monomer released from composite resins changed according to the type of composite resin and the light mode used.
Radioactive Potential of Zirconium-Dioxide Used for Dental Applications
(Sage Publications Ltd, 2014) Bavbek, Andac Barkin; Ozcan, Mutlu; Eskitascioglu, Gurcan
Purpose: The purpose of this study was to investigate the possible radioactive potential of zirconium dioxide (ZrO2) dental ceramics. Such information is necessary since they became an integral part of routine prosthetic rehabilitations and devoid of scientific information about their radioactivity creates some concern in the dental community. Methods: Four different types of commercial ZrO2 ceramics, namely Lava, Cercon, ICE Zirkon, and Everest Bio ZS were investigated before and after the sintering process. Sintering temperatures were applied according to each manufacturer's instructions. The compositions of the presintered and sintered specimens were analyzed using x-ray fluorescence spectrometer (XRF). Concentrations of the elements and compounds were also measured by this method. Determination of radioactivity continued with gamma-spectrometry measurements and gross alpha/beta analyses. Results: The activity of gamma and gross alpha/beta was below minimum detection limits (MDL) for presintered and sintered ZrO2. The MDLs of gross alpha/beta counting system were 0.02 Bq/g and 0.01 Bq/g for alpha and beta radioactivity, respectively. The sintering process played only a minor role in the composition of the compounds. Conclusions: Radioactivity of the ZrO2 ceramics studied showed negligible radionuclide activity that can be considered lower than many hazardous radioactive appliances in our environment.