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Now showing 1 - 10 of 10
  • PublicationMetadata only
    The effect of home bleaching agents on the surface roughness of five different composite resins: A SEM evaluation
    (2016-05-01T00:00:00Z) Cengiz, Esra; Kurtulmus-Yilmaz, Sevcan; Ulusoy, Nuran; Deniz, ŞULE TUĞBA; Yuksel-Devrim, Ece; DENİZ, ŞULE TUĞBA
    The aim of this study was to investigate the effect of hydrogen peroxide (HP) and carbamide peroxide (CP) on the surface roughness of five different composite resins using profilometer and scanning electron microscope (SEM). Thirty-six specimens (1mm thick, 10mm in diameter) of five composite resins were fabricated. Each composite group was equally divided into three subgroups as control, CP and HP. In control group, specimens were stored in daily refreshed distilled water during the 14-day testing period. In other groups, 10% HP (Opalescence Treswhite) and 10% CP (Opalescence PF) were applied and surface roughness values (Ra) of each specimen were measured with a profilometer at the end of 14 days. Additionally, SEM analysis was performed to evaluate the surface deformations of composite resins. Data were analyzed with Kruskal-Wallis and Mann-Whitney U tests. Ra values of composite groups exposed to bleaching agents were statistically higher than control group (p<0.05). There was no significant difference between Ra values after HP and CP application within each composite group while SEM micrographs showed higher surface alterations at HP group compared to CP. Among the composite resins tested, Ceram-X Mono revealed the lowest Ra values after CP and HP applications as seen at SEM images. Home bleaching agents increased the surface roughness of all composites. Except CP applied Ceram-X mono specimens, Ra values of all composite resins evaluated in this study exceeded the critical limit of 0.2m. Ceram-X mono was the least affected composite material after bleaching application. SCANNING 38:277-283, 2016. (c) 2016 Wiley Periodicals, Inc.
  • PublicationMetadata only
    Effect of bleaching agents and whitening dentifrices on the surface roughness of human teeth enamel
    (2013-05-01T00:00:00Z) Ozkan, Pelin; Kansu, Gulay; Ozak, ŞULE TUĞBA; Kurtulmus-Yilmaz, Sevcan; Kansu, Pelin; DENİZ, ŞULE TUĞBA
    Objective. The aim of this in vitro study was to evaluate the surface roughness of human enamel bleached with 10% carbamide peroxide or 10% hydrogen peroxide bleaching agents at different times and also subjected to different superficial cleaning treatments. Materials and methods. One hundred and forty flat enamel samples were divided into 14 groups, Group 1-Group 14 (G1-G14). G1-G7 were treated with 10% carbamide peroxide and different dentifrices, G8-G14 were treated with 10% hydrogen peroxide and different dentifrices (G1 and G8: not brushed as control groups; G2 and G9: brushed with Ipana (R) toothpaste; G3 and G10: brushed with Clinomyn (R) toothpaste; G4 and G11: brushed with Moos Dent (R) toothpaste; G5 and G12: brushed with Signal (R) toothpaste; G6 and G13: brushed with Colgate (R) toothpaste; G7 and G14: brushed without dentifrice). A profilometer was used to measure average roughness values of the initial surface roughness and at each 7-day-interval. The bleaching was performed for 6 h a day and the surface cleaning treatment was performed 3-times a day, 2 min each time, for 4 weeks. The samples were stored in distilled water during the test period. Results. Statistical analysis revealed significant differences in surface roughness values over time for all groups except G1 and G8 (not brushed). The results of the surface roughness of all groups were nearly the same. Conclusions. The bleaching with 10% hydrogen peroxide and 10% carbamide peroxide did not alter the enamel surface roughness, but when the bleaching treatment was performed combined with abrasive dentifrices, a significant increase in roughness values was observed.
  • PublicationMetadata only
    Antimicrobial Activity of Ozone against Pathogenic Oral Microorganisms on Different Denture Base Resins
    (2019-06-07T00:00:00Z) Hayran, Yeliz; DENİZ, ŞULE TUĞBA; Aydin, Ali; DENİZ, ŞULE TUĞBA
    The present study aimed to evaluate the antimicrobial effect of gaseous ozone against specific oral pathogens on denture base resins. 1080 round samples were prepared (10mm-diameter, 2mm-thickness). Candida albicans, Streptococcus mutans, Streptococcus gordonii, and Aggregatibacter actinomycetemcomitans, polyamide-Deflex, heat-cured polymethyl-methacrylate (PMMA)-QC-20, and cold-cured-PMMA-Meliodent. The doses and durations: 25, 50 and 100 mu g/ml, 5, 10, 20, 30 minutes. For Cell viability (CV) MTT was used. 100 mu g/ml was most effective dose for C. albicans, S .gordonii, and A. actinomycetemcomitans were in heat-cured-PMMA and polyamide for S.mutans. For polyamide, lowest CV was 43% in S.mutans and A.actinomycetemcomitans. CV of heat-cure and cold-cure PMMA were 31% and 32% in S.gordonii, respectively. CV was similar for all resins and durations in S.mutans and A.actinomycetemcomitans and for polyamide for C.albicans and for heat-cure PMMA for S.gordonii. 30-min ozone application killed 80% of all microorganisms in all resins except for C.albicans in polyamide (65% cell death) and cold-cure PMMA (57% cell death). Optimal dose/duration combination was 100 mu g/ml-10 min. Gaseous ozone can be considered as an effective cleansing agent for denture base resins.
  • PublicationMetadata only
    Effect of atmospheric plasma versus conventional surface treatments on the adhesion capability between self-adhesive resin cement and titanium surface
    (2015-06-01T00:00:00Z) Seker, Emre; Kilicarslan, Mehmet Ali; Deniz, ŞULE TUĞBA; Mumcu, Emre; Ozkan, Pelin; DENİZ, ŞULE TUĞBA
    PURPOSE. The aim of this study was to evaluate the effects of atmospheric plasma (APL) versus conventional surface treatments on the adhesion of self-adhesive resin cement to Ti-6Al-4V alloy. MATERIALS AND METHODS. Sixty plates of machined titanium (Ti) discs were divided into five groups (n=12): 1) Untreated (CNT); 2) Sandblasted (SAB); 3) Tribochemically treated (ROC); 4) Tungsten Carbide Bur (TCB); 5) APL treated (APL). SEM analysis and surface roughness (Ra) measurements were performed. Self-adhesive resin cement was bonded to the Ti surfaces and shear bond strength (SBS) tests, Ra and failure mode examinations were carried out. Data were analyzed by one-way analysis of variance and chi-squared test. RESULTS. The lowest SBS value was obtained with CNT and was significantly different from all other groups except for APL. The ROC showed the highest SBS and Ra values of all the groups. CONCLUSION. It was concluded that the effect of APL on SBS and Ra was not sufficient and it may not be a potential for promoting adhesion to titanium.
  • PublicationMetadata only
    The effect of home-bleaching application on the color and translucency of five resin composites
    (2013-11-01T00:00:00Z) Kurtulmus-Yilmaz, Sevcan; Cengiz, Esra; Ulusoy, Nuran; Ozak, ŞULE TUĞBA; Yuksel, Ece; DENİZ, ŞULE TUĞBA
    Objectives: The aim of this study was to investigate the effect of home bleaching agents on the color and translucency of resin composites.
  • PublicationMetadata only
    The effect of immediate dentin sealing with chlorhexidine pretreatment on the shear bond strength of dual-cure adhesive cement
    (2021-07-01T00:00:00Z) DENİZ, ŞULE TUĞBA; OĞLAKÇI, Burcu; Yesilirmak, Sevda Ozturk; DALKILIÇ, Evrim; DENİZ, ŞULE TUĞBA; OĞLAKÇI, BURCU; DALKILIÇ, EVRIM
    The purpose of this in vitro study was to evaluate the effect of immediate dentin sealing (IDS) with and without chlorhexidine (CHX) pretreatment on the shear bond strength (SBS) of dual-cure adhesive resin cement. Mid-coronal dentin surfaces were obtained from 75 human molars. They were randomly allocated into five groups in accordance to type of IDS [etch&rinse/ER (Adper Single Bond2) and universal/U adhesive systems (Single Bond Universal)] and presence of CHX application (n = 15): Group ER; Group ER + CHX; Group U; Group U + CHX; and Group C (no IDS). Dual-cure adhesive resin cements were bonded with a cylinder-shaped Teflon mold. The SBS was measured using a universal test machine. Fracture type was evaluated with stereomicroscope. The resin/dentin interfaces were examined with an environmental scanning electron microscope. Data were statistically analyzed with two-way analysis of variance and Bonferroni tests (p .05). Group U + CHX showed significantly higher SBS than Group C (p .05). The prevalent failure mode was the mixed type for most of the groups. Group C exhibited an intact and regular hybrid layer with no resin tag, whereas longer and clear resin-tag formation was visible for Group U + CHX. CHX pretreatment improved the bond strength between adhesive resin cement and dentin when IDS treatment was performed with a universal adhesive system.
  • PublicationMetadata only
    Efficacy of denture cleaners on the surface roughness and Candida albicans adherence of sealant agent coupled denture base materials
    (2016-10-01T00:00:00Z) Koroglu, Aysegul; Sahin, Onur; Dede, Dogu Omur; Deniz, ŞULE TUĞBA; Sever, Nurdan Karacan; Ozkan, Serkan; DENİZ, ŞULE TUĞBA
    This study investigated the effect of denture cleansers on the surface roughness and Candida albicans adherence of surface sealant agent coupled denture base resins. One hundred and twenty specimens were fabricated from 2 polymethyl methacrylate (PMMA) (Meliodent; Acron MC) and 1 polyamide (Deflex) denture base materials, coated with a sealant agent (Palaseal) and divided into 4 groups (n=10) according to overnight cleaning procedures: distilled water (control), 5% sodium hypochlorite (NaOCl) and two different sodium perborate (Corega; Rapident). The surface roughness values were measured with a profilometer before (R(a)0) and after 90 days immersion in denture cleaners (R(a)1). Specimens were incubated with Candida albicans suspension and Candida colony forming units (CFU) (Cfu/mm) were counted. Significant differences were found, between the R(a)0 and R(a)1 values of 5% NaOCl applied Acron MC, Deflex and also Rapident applied Deflex groups (p<0.05). Denture cleaning procedures had no significant effects on the quantitiy of Candida albicans.
  • PublicationMetadata only
    Evaluation of staining susceptibility of resin artificial teeth and stain removal efficacy of denture cleansers
    (2014-11-01T00:00:00Z) Kurtulmus-Yilmaz, Sevcan; Deniz, ŞULE TUĞBA; DENİZ, ŞULE TUĞBA
    Objective. To assess the staining susceptibility of four acrylic resin (Ivostar, SR Vivodent PE, Major Dent, Integral) and a nanocomposite resin (Veracia) artificial teeth and to evaluate the stain removal efficacy of denture cleansers. Materials and methods. Sixty maxillary incisors of each brand (total = 300) were divided into three groups according to staining solution as coffee, red wine and tea. Baseline color measurements were performed with a spectrophotometer. Specimens were immersed in staining solutions for 14 h (2 h x 7 days) and then second color measurements were performed. Each group was further divided into four sub-groups according to denture cleanser as Corega tabs, Fittydent, NaOCl (0.5%) and distilled water (control) (n = 5). Specimens were immersed in denture cleansers for 8 h and third color measurements were made. Thus, the weekly simulation period was completed. This cycle was repeated 12 times to simulate a 3-month time period and measurements were performed at the end of the 4th, 8th and 12th cycles. Delta E values were calculated and data were analyzed with 3-way repeated measures ANOVA and Bonferroni tests. Results. Significant color differences were found among the teeth and staining solutions, but all of the color differences were in the clinically acceptable range (Delta E < 5.5). Integral showed the highest Delta E values for all solutions, while Ivostar and Vivodent demonstrated the lowest Delta E values for red wine and tea solutions. There was no significant difference among the denture cleansers in terms of stain removal efficacy. Conclusions. Cross-linked acrylic (Integral) and nanocomposite (Veracia) resin teeth were more susceptible to staining. Denture cleansers were efficient on stain removal from artificial teeth.
  • PublicationMetadata only
    Efficacy of uncommon surface treatment methods on titanium in order to improve bond strengths for adhesive cementation
    (2016-01-01T00:00:00Z) Kilicarslan, Mehmet Ali; Ozkan, Pelin; Mumcu, Emre; Deniz, ŞULE TUĞBA; DENİZ, ŞULE TUĞBA
    The aim of this study is to comparison of effects of uncommon surface treatments, especially new alternatives on the adhesive strength between resin and titanium surfaces. Fifty-five titanium disks were prepared and they were separated into 5 groups as follows:(1) Control group; (2) Tribochemical treatment group in the laboratory; (3) Tribochemical treatment group in the clinic; (4) Acid etch group; and (5) Nd:YAG Laser-irradiated group. Surface roughness of the specimens was measured using a profilometer, and the topographic patterns were observed by scanning electron microscope. After these tests, resin cement was applied to the titanium samples. Shear bond test was performed via a universal testing machine at a crosshead speed of 0.5 mm/minute. In addition, the correlation between the surface roughness and bond strength was checked using Spearman correlation test (0.01 level). The highest surface roughness value was observed for the acid etch group (1.53 mu m). The highest mean shear bond strength was recorded with the tribochemical procedure group in the laboratory (13.74 MPa) and the lowest with the control group (3.69 MPa). A positive correlation was found between the bond strength and surface roughness for all groups. All of the surface treatment methods that were used in present study increased the bond strength between resin and titanium except for the laser group.
  • PublicationOpen Access
    The accuracy of the prediction models for surface roughness and micro hardness of denture teeth
    (2019-12-01T00:00:00Z) DENİZ, ŞULE TUĞBA; Ozkan, Pelin; Ozkan, Gulay; DENİZ, ŞULE TUĞBA
    The paper aimed to compare the performance of artificial neural network (ANN) model with the results of in vitro experiments. For these experiments, maxillary molars of four different denture teeth were subjected to tea, coffee, cola, cherry juice, distilled water. Vickers microhardness and surface roughness values were measured. Subsequently, ANN model for the prediction of microhardness and surface roughness of different denture teeth were examined. A back-propagation ANN has been used to develop a model relating to the amount of microhardness and surface roughness. The independent variables of the model are distilled water, tea, filtered coffee, cola, cherry juice, time and denture teeth. Microhardness and surface roughness were chosen as the dependent variables. According to the results, a neural network architecture having one input layer with ten neurons, two hidden layers with six neurons, one output layer with two neurons and an epoch size of 48 gives better prediction. Prediction models for dental materials could also be supportive for in vitro studies.