Person: ÖZKAN, YASEMİN
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ÖZKAN
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YASEMİN
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Publication Metadata only The effect of thermocycling on peel strength of six soft lining materials(BLACKWELL PUBLISHING LTD, 2002) ÖZKAN, YASEMİN; Sertgoz, A; Kulak, Y; Gedik, H; Taskonak, BThe bond strength of two heat-cured and four cold-cured soft lining materials was compared using a peeling test method before and after thermocycling. Tested soft lining materials were Molloplast B, Mollosil, Ufigel P, Ufigel C, Permaquick and Permaflex. Six specimens, 6.5 x 2 x 0.3 cm, for each group were prepared according to the manufacturers' instructions. Control groups were stored in a humidor for 24 h, whereas the others were thermocycled in a water bath between the 5 and 55 degreesC for 5000 cycles. Peel strength of samples were measured using an Instron Universal testing machine at a cross-head speed of 5 mm min(-1) . The types of failure were observed using an electron microscope. The highest peel bond strength values were calculated for Permaflex and Permaquick before and after thermocycling, respectively. Molloplast B, Mollosil, Ufigel P and Permaquick demonstrated an increase in peel strength after thermocycling, with Permaquick lining material having statistically significant increase. However, decrease in peel strength was observed for Ufigel C and Permaflex after thermocycling. Failure mode within the control groups was cohesive for Molloplast B, Permaquick and Permaflex, whereas adhesive for Ufigel P and Ufigel C. Mollosil demonstrated a mixed mode of failure for both thermocycled and control groups.Publication Metadata only Three-year treatment outcomes with three brands of implants placed in the posterior maxilla and mandible of partially edentulous patients(MOSBY-ELSEVIER, 2007) ÖZKAN, YASEMİN; Ozkan, Yasar; Ozcan, Mutlu; Akoglu, Burcin; Ucankale, Mert; Kulak-Ozkan, YaseminStatement of problem. Survival rates of implants in posterior regions vary among clinical studies. Problems occur more often in the posterior segment of the maxilla due to proximity of the maxillary sinus and reduced quality or quantity of alveolar bone. Purpose. This clinical study evaluated the treatment outcomes of 3 brands of implants in the posterior maxillac and mandibles of 63 patients. Treatment outcomes of all implants were assessed according to implant type, location, patient gender, periodontal status, and prosthesis type. Material and methods. A total of 203 implants - 105 ITT (ITT), 53 Camlog (CAM), and 45 Frialit (FRI) - were placed in 63 patients (38 women, 25 men). One hundred twelve implants were located in the posterior mandible and 91 in the posterior maxilla. All implants were longer than 10 mm and had a diameter larger than 3.5 mm. Implants in the ITT group were placed in a 1-stagc surgery. The CAM and FRI groups were treated with a 2-stage surgical protocol. Implants were not loaded until osseointegration was complete, which was determined clinically and radiographically. At that point, implants were restored with 50 single crowns and 81 fixed partial dentures (FPDs). While 11 FPDs connected implants to natural teeth, 70 FPDs were supported by implants only. Standardized radiographs were made, and clinical parameters were recorded at prosthesis insertion (baseline) and at each recall evaluation (6, 12, 24, and 36 months). Plaque index (PT), sulcus bleeding index (SBI), peri-implant probing depth (PD), and radiographic marginal bone loss (MBL) levels were recorded at baseline, along with any biological and mechanical complications. Repeated-measures ANOVA, Kruskal-Wallis test, Wilcoxon signed rank test, and paired samples tests were used for statistical analysis (alpha = .05). Results. One implant was lost during the osseointegration period in I woman due to infection. The cumulative implant treatment outcome was 99.3%. At the 3-year recall, plaque accumulation was significantly higher than baseline scores (P = .01, Wilcoxon signed rank test). Eight percent of the patients presented >2 mm PD at 2-year recall. The influence of observation time was found to be significant for the mean MBL values between groups (P = .001). When MBL values were compared between groups, no significant differences were found. For I patient in the FRI group, abutment loosening was observed and both the crown and the abutment were replaced. Patient satisfaction in all groups was high. Conclusion. The 3 brands of implants evaluated in this study exhibited similar positive treatment outcomes after 3 years.Publication Metadata only Satisfaction of the complete denture wearers related to various factors(2009) TÜRKER, ŞEBNEM BEGÜM; Turker S.B., Sener I.D., Özkan Y.K.All dentists who have worked with complete denture wearers know that patient satisfaction is not based only on the technical quality of the dentures. The aim of this study was at assessing the effect of gender, the number of the dentures used before, the length of time of denture usage, education and age on the satisfaction of the complete denture wearers. The students of the Dental Faculty of Marmara University (Turkey) made new dentures for 342 patients who were asked to participate in the investigation. The subjects (137 men and 205 women) were 39-89 years of age with a mean of 61.62 years. The attitude toward dentures in general was measured by means of 11 items of a questionnaire. The 10 main questions of the questionnaire were answered by the participants, and quantified on a 7-point scale, while the 11th issue (general satisfaction) was evaluated on a scale of 1-10. All main factors were also estimated in subgroups. For example, the education was analyzed in 4 subgroups, the time of denture usage was divided into two subgroups (below and above 3 years) and the number of dentures used before was also taken as up to 3 or more than 3 dentures. The age of the subjects was taken in 3 subgroups: 40-55, 56-65 and >65 years. One-way ANOVA, Tukey and Student t-tests were used to evaluate the answers to the questionnaire. Our patients displayed statistically significant differences only in the topics of their ability of cleaning their dentures, due to education and number of previously used dentures. © 2008 Elsevier Ireland Ltd. All rights reserved.Publication Metadata only Effect of thermocycling on tensile bond strength of six silicone-based, resilient denture liners(MOSBY-ELSEVIER, 2003) ÖZKAN, YASEMİN; Kulak-Ozkan, Y; Sertgoz, A; Gedik, HStatement of problem. Adhesion failure between silicone resilient denture lining materials and denture base resin is commonly encountered in clinical practice. Adhesion failure results in localized unhygienic conditions at the debonded regions and often causes functional failure of the prosthesis. Purpose. The purpose of this study was to investigate the effect of thermocycling on the tensile bond strength of 6 soft lining materials. Material and methods. Six commonly used silicone-based resilient denture liners (Ufigel C, Ufigel P, Mollosil, Molloplast B, Permafix, and Permaflex) were chosen for the investigation. The bond strength was determined, in tension, after processing to PMMA. The resilient denture liners for each group (n = 24) were 10 X 10 X 3 turn and were processed between 2 polymethyl methacrylate specimens according to manufacturer's instructions. Two PMMA specimens were prepared by investing brass dies with a 3-mm-thick spacer in a denture flask. Specimens were made by processing the resilient denture liners against the polymerized PMMA block. After polymerization, the brass spacer was removed from the mold, the 2 PMMA resin specimens were trimmed, and the surfaces to be bonded were smoothed. The PMMA block was placed back into the molds and the resilient denture liners were packed into the space made by brass spacer, trial packed, and polymerized according to the manufacturer's instructions. Half of the specimens for each group were stored in water for 24 hours, and the other half were thermocycled (5000 cycles) between baths of 5degrees and 55degreesC. All specimens were placed under tension until failure in a universal testing machine at a crosshead speed of 5 mm/min. The maximum tensile stress before failure and mode of failure were recorded. The mode of failure was characterized as cohesive, adhesive, or mixed mode, depending on whether the fracture surface was in the soft liner only, at the denture base-soft liner interface only, or in both. Failure strength was recorded in kg/cm(2). Results were tested by multiple analysis of variance (ANOVA) for mode of failure (adhesive, cohesive, and mix), 2-way ANOVA (storage-products), and 1-way ANOVA (storage-products interaction, before and after thermocycling). Duncan's test was used to determine whether significant changes in the tensile bond properties of the materials occurred during thermocycling. Results. Varying degrees of bond strengths were found for soft lining materials and were significantly different (P<.05). Results of this study also indicated that the bond strengths of soft lining materials had significantly decreased after thermocycling except Ufigel C and Mollosil. Conclusions. Because the adequate adhesive value for soft lining materials is given 4.5 kg/cm(2), all of the materials were acceptable for clinical use. (J Prosthet Dent 2003;89:303-10.)Publication Metadata only The effect of surface roughness of silicone-based resilient liner materials on the adherence of Candida albicans and inhibition of Candida albicans with different disinfectants(Quintessence Publishing Co., Ltd, 2009) ÖZKAN, YASEMİN; Gedik H., özkan Y.K.Purpose: The objective of the present study was to evaluate surface roughness and adherence of Candida albicans and to determine the effectiveness of denture cleansers in the disinfection of silicone-based soft lining materials. Materials and Methods: Two types of silicone-based soft lining materials (four room temperature polymerised soft lining materials [RTPSLM]: Ufi Gel P, Ufi Gel C, Mollosil and Soft-Liner; and two high temperature polymerised soft lining materials [HTPSLM]: Moloplast B and Luci Soft) and seven denture cleansers (Efferdent, Polident, Steradent, Corega, Denclen, Klorhex and Axion) were tested in the present study. For each soft lining material, 56 samples (10 mm · 10 mm · 3 mm) were prepared. Surface roughness measurements were made using a profilometer with an optical scanner probe. All samples were ultrasonically cleaned in water for 15 s, autoclave sterilised and contaminated with C. albicans solutions for adherence assay evaluation. After the evaluation, the samples were immersed in seven different denture cleansers. The results were expressed as the ratio of cells remaining after each cleanser in comparison with the control group. Results: HTPSLM showed a lower surface roughness value (2.21 ± 0.30 lm) than RTPSLM (2.39 ± 0.40 lm), but these differences were not statistically significant (P > 0.05). Also, HTPSLM showed lower adhesion of C. albicans (mean ranks 136.35) than RTPSLM (mean ranks 138.64), but the differences were not statistically significant (P > 0.05, one- or two-way analysis of variance). In the C. albicans removal test, all denture cleansers showed a strong effect on both silicone-based soft lining materials. HTPSLM showed lower removal activity (mean ranks 30.01) than RTPSLM (mean ranks 25.86), but these differences were not statistically significant (P > 0.05). Although there were no significant differences between disinfectants on both silicone-based soft lining materials, Axion was found to be the most effective disinfectant. Corega, Polident, Denclen, Steradent and Efferdent showed the most effective cleansing, respectively. Conclusions: RTPSLM and HTPSLM did not show significant differences in the surface roughness value; also they showed no significant differences in the adhesion rate of C. albicans. All tested silicone-based soft lining materials showed adherence of C. albicans after contamination procedures, and removal activity for C. albicans was observed in all tested silicone-based soft lining materials after disinfection procedures. © Quintessence.Publication Metadata only Adherence of Candida albicans to denture base acrylics and silicone-based resilient liner materials with different surface finishes(SPRINGER HEIDELBERG, 2007) KADİR, TANJU; Nevzatoglu, Erdem U.; Ozcan, Mutlu; Kulak-Ozkan, Yasemin; Kadir, TanjuThis study evaluated the surface roughness and Candida albicans adherence on denture base acrylic resins and silicone-based resilient liners with different surface finishes. Four commercial denture base acrylic resins ( three heat polymerized and one room temperature polymerized) and five silicone-based liner materials ( two heat polymerized and three room temperature polymerized) ( 10 x 10 x 2 mm) were tested in this study. The materials were processed against glass or plaster or finished with a tungsten carbide bur. Surface roughness measurements were made using a profilometer with an optical scanner probe. All specimens were ultrasonically cleaned in water for 15 s, autoclave sterilized, and contaminated with C. albicans solution for adherence assay evaluation. The materials processed against the glass surface showed significantly lower surface roughness values (0.11 +/- 0.1-1.66 +/- 1.1 mu m) than those of the materials processed against the dental plaster (2.61 +/- 0.2 6.12 +/- 2.8 mu m) or roughening with a bur (1.48 +/- 0.2 - 7.05 +/- 1.2 mu m; p < 0.05, one- or two-way analysis of variance). Also, the materials processed against the glass surface showed lower C. albicans adhesion ( mean ranks 120.36) than those of the materials processed against the dental plaster ( mean ranks 139.77) or roughening with a bur ( mean ranks 143.06), but the differences were not statistically significant (p > 0.05, Kruskal - Wallis and Mann - Whitney). In all types of surface finishes, C. albicans adhesion on denture base acrylics was significantly less ( mean ranks 90.18 90.40) than those of silicone liners (mean ranks 119.38 205.18; p < 0.01, Kruskal-Wallis).Publication Metadata only Effects of Bartter's syndrome on dentition and dental treatment: A clinical report(MOSBY-ELSEVIER, 2005) GÖZNELİ, RİFAT; Gozneli, R; Ozkan, YK; Kazazoglu, E; Alkalin, ZFBartter's syndrome is an autosomal recessive form of severe volume depletion due to renal salt wasting. This clinical report describes the prosthodontic treatment for a 24-year-old man who suffers from Bartter's syndrome. The treatment plan included endodontic treatment of the maxillary anterior incisors and placement of cast dowel-and-core restorations because of reduced crown height. The patient's remaining teeth were restored with metal-ceramic crowns.Publication Metadata only Prevalence of essential tremor: A door-to-door survey in Sile, Istanbul, Turkey(ELSEVIER SCI LTD, 2009) ÖZKAN, YASEMİN; Sur, Haydar; Ilhan, Selen; Erdogan, Huelya; Oeztuerk, Esat; Tasdemir, Mustafa; Boerue, Uelkue TuerkThe aim of this study was to determine the prevalence of essential tremor (ET) in a Turkish population living in Sile, a rural town located on Black Sea coast of Istanbul. This study was designed as a descriptive cross-sectional field study. People aged 18 years and over were selected for the study. Tremor surveillance questionnaire was applied by door-to-door visits. Subsequently, all subjects who answered the questionnaire had a standard tremor examination. Diagnosis was made based on Washington Heights-Inwood Genetic Study of Essential Tremor (WHIGET) diagnosis and clinical evaluation scale. A total of 2227 people was screened. The prevalence of ET was found to be 3.09% (95% Cl = 2.42-3.91%) in Turkish population aged over 18 years. The prevalence of ET increased by age in both genders. (C) 2008 Elsevier Ltd. All rights reserved.