Browsing by Author "Donmez, Nazmiye"

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Citation Count: 4
Effect of Acid Etching and Er: YAG Laser Enamel Conditioning on the Microleakage of Glass Carbomer Fissure Sealants
(Univ indonesia, Fac dentistry, 2020) Ozveren, Neslihan; Uslu, Yesim Sesen; Donmez, Nazmiye
Objective: This study aimed to evaluate the effects of Er:YAG laser used alone or in combination with acid etching as surface conditioners on the microleakage of a glass carbomer fissure sealant for permanent molar teeth. Methods: Forty sound human permanent molar teeth were randomly divided into four experimental groups based on enamel etching methods: group I, no surface conditioning; group II, 37% phosphoric acid etching; group III, Er:YAG laser etching; and group IV, sequential laser etching and acid etching. After surface conditioning procedures were conducted, the teeth were sealed with a glass carbomer seal. The teeth were subjected to thermocycling with 2500 cycles at 5 +/- 2 degrees C to 55 +/- 2 degrees C for 24 h. Subsequent microleakage was assessed via dye penetration under a stereomicroscope. Results: Group II showed the lowest microleakage scores. Groups III and IV exhibited similar score distribution, which was lower than that of group I. Conclusions: Laser etching and acid etching decrease the microleakage probability of glass carbomer sealants, and acid etching alone provides a more suitable surface for these sealants. Sequential laser etching and acid etching have no additional benefit in comparison with acid etching alone and yield worse results than those of the other tested methods.
Citation Count: 3
The effect of additional chlorhexidine and/or ethanol on the bond strength of universal adhesives
(Taylor & Francis Ltd, 2021) Kaynar, Zeynep Buket; Kazak, Magrur; Donmez, Nazmiye; Dalkilic, Evrim Eliguzeloglu
The aim of this study was to evaluate the effect of chlorhexidine and/or ethanol application on the bond strength of two universal adhesive systems. 36 extracted human teeth were used in this study. Standard Class I cavities (4 x 3 x 3mm) were prepared and divided into two groups according to the adhesive systems used. Each group was subdivided into three subgroups to be treated with chlorhexidine, ethanol, or unexposed to any solution. Group I; Universal bond I was applied without any treatment. Group II; 2% chlorhexidine was applied, before the application of universal bond I. Group III; 100% ethanol was applied, before the application of universal bond I. Group IV; Universal bond II was applied without any treatment. Group V; 2% chlorhexidine was applied, before the application of universal bond II. Group VI; 100% ethanol was applied, before the application of universal bond II. Then, teeth were restored with a nano-hybrid resin composite then subjected to thermo-cycling (10,000 cycles, 5-55 degrees C). All teeth were exposed to 50,000 cycles of loading in a chewing simulator. Twelve sticks from each group were obtained using a cutting machine. Sticks were subjected to a microtensile bond strength. After procedures, fractured surfaces were observed under a stereomicroscope to determine the mode of failure. Hybrid layer of each group was evaluated under a scanning electron microscope (SEM). Data were submitted to the Kruskal Wallis test. Significance level was set at 5%.No statistically significant differences were shown in all groups (p > 0.05). The lowest bond strength value was obtained in group II (9.76), the highest bond strength value was determined in group IV (20.57). The study concluded that additional chlorhexidine or ethanol treatment may not influence directly the bond strength of universal adhesives when using a single-step self etch mode of universal adhesives.
Citation Count: 0
The Effects of Thermo-mechanical Aging on Microleakage in Composite Restorations Polymerized Using One New Generation and Two Conventional Led Light Curing Units
(Bezmialem Vakif Univ, 2021) Donmez, Nazmiye; Uslu, Yesim Sesen; Siso, Seyda Herguner; Toprak, Ali
Objective: This study aimed to evaluate the effects of thermomechanical aging (TMA) on the microleakage scores of Class V composite restorations polymerized using one new generational and two conventional light emitting diodes (LED) light curing units (LCU). Methods: Class V cavities were prepared and restored on the buccal and lingual surfaces of 60 extracted human premolar teeth using a dental phantom head to simulate clinical conditions. After application of the adhesive system (Optibond Solo Plus, Kerr, USA) using total etch procedures. the cavities were restored with composite resin (Herculite XRV. Kerr, USA) using one new generational (Demi Ultracapacitor, Kerr, USA) and two conventional (Valo Cordless, USA and BA Optima International, UK) LED light devices. The restored teeth were then subdivided into the test (underwent TMA) and control (did not undergo TMA) groups, and the specimens were stained with 0.5% basic fuchsin dye and sectioned. Dye penetration was scored using a stereomicroscope at 40x magnification. Differences between groups were compared using the Kruskal-Wallis, Mann-Whitney U, and Wilcoxon Signed Ranks tests (p<0.05). Results: Comparison of the test and control groups by the LCUs used for polymerization showed a statistically significant difference in microleakage scores between the two (p<0.05). However, no differences in scores were observed between the new generational and two conventional LED LCUs (p>0.05). Conclusion: Thermal and mechanical aging procedures increased microlcakage in Class V composite estorations, regardless of the light curing unit used.
Citation Count: 4
The effects on dentin tubules of two desensitising agents in combination with Nd:YAG laser: An in vitro analysis (CLSM and SEM)
(Elsevier Sci Ltd, 2020) Uslu, Yesim Sesen; Donmez, Nazmiye
Objectives: The aim of this study was to assess in vitro the effects of two desensitising agents containing calcium phosphate and nano-hydroxyapatite, applied alone or with Nd:YAG laser, on dentin tubule occlusion, and to determine the penetration depth. Methods: 75 extracted human 3rd molar teeth were used. The effects of desensitising treatments and erosion resistance were evaluated on dentin tubule occlusion via SEM and the dentin tubule penetration depth via CLSM. Two desensitising agents-Teethmate (TMD), (Kuraray, Japan) and Professional Oral Care Nano-hydroxyapatite (Nhap) Desensitiser (Miromed Group SA, Italy)-were used. Study groups were designated as Group 1(Control), Group 2(TMD), Group 3(TMD+Nd:YAG), Group 4(Nhap) and Group 5(Nhap+Nd:YAG) and were assigned 10 dentin discs per group. After treatment with desensitising agents and laser, dentin discs were exposed to artificial saliva for one night in samples prepared to be without erosion and a sample prepared as with erosion was exposed 3 times per day for 5 days to 0.3% citric acid cycles. The Image J programme was used to scale the images of SEM analyses. The agents were mixed with 0.1% Rhodamine B for testing penetration depth and samples were analysed with CLSM after applying with and without laser. The obtained images were evaluated using the Zeiss ZEN Lite, Zeiss Microscopy programme (Carl Zeiss, Germany). Data were analysed with MannWhitney U and Kruskal Wallis tests (p < 0.05). Results: Statistically significant differences from the control group were found in all treatment groups. The TMD +Nd:YAG group had the lowest number of open tubules before and after erosion and the highest penetration depth. The Nd: YAG laser markedly increased the efficiency of the desensitising agents.
Citation Count: 0
Examination of caries-affected dentin and composite-resin interface after different caries removal methods: A scanning electron microscope study
(Wiley, 2022) Kaynar, Zeynep Buket; Kazak, Magrur; Kaynar, Zeynep Buket; Uslu, Yesim Sesen
To evaluate the caries-affected dentin and composite-resin interface with scanning electron microscopy (SEM) after different caries removal methods in human molars. Twelve with extensive approximal caries lesions that did not reach the pulp and five caries-free molars (control group [CG]) were used. Carious teeth were divided into four experimental groups: Atraumatic Restorative Treatment (ART), Rotary Instrument (RI), Photo-Ablation, and Papain-Based Enzymatic Gel (Brix 3000 (R), Brix, Brazil). Class II slot cavities were prepared with RI in the CG. Then all caries removed teeth and control groups were restored (All-Bond Universal, BISCO, USA; Clearfil MajestyES-2, Kuraray, Japan). Specimens were prepared for SEM examinations. Hybrid layer (HL) thicknesses were measured using Image) programme. Gap measurements were performed with micro-CT. Data were analyzed with ANOVA and posthoc Dunnett's t-tests (p < .05). The highest HL thickness was found in Photo-Ablation Group, and a statistically significant difference was observed among the control and experimental groups (p < .05). The lowest HL thickness was measured in the Enzymatic Gel Group. In terms of internal gap formation, CG showed statistically significant differences compared to the other groups (p < .05). The highest internal gap was observed in RI Group, while the lowest gap was observed in CG. According to SEM, a uniform HL and resin tags were seen in the CG. Smear layer, irregular HL, and gap formation were observed in ART Group. In RI Group, nonuniform HL formation and resin tags were observed. In Photo-Ablation Group, a uniform HL without smear layer and internal gap was observed. In the Enzymatic Gel Group, both opened dentinal tubules, and melting-like formations were observed on the dentin surface. Especially melting-like formations were observed in peritubular dentin. It can be concluded that all caries removal methods except rotary instrumentation were conservative methods, which preserve more healthy dental tissues. Research highlights Among the caries removal procedures, the photo-ablation caries removal method stands out with the highest hybrid layer (HL) thickness and the lowest internal gap formation. Despite having the lowest HL thickness, the enzymatic gel method can be advantageous for patients requesting an alternative caries removal instead of a rotary instrument.
Citation Count: 16
Knowledge, stress levels, and clinical practice modifications of Turkish dentists due to COVID-19: a survey study
(Sociedade Brasileira de Pesquisa Odontologica, 2021) Sarialioglu Gungor, Ayca; Donmez, Nazmiye; Uslu, Yesim Sesen
Dentists are exposed to the highest risk of occupational respiratory and droplet infections by working face-to-face with patients. The aim of this study was to investigate the knowledge of symptoms and modes of transmission of COVID-19, stress levels and clinical practice modifications of Turkish dentists during the COVID-19 pandemic. An online survey (15 questions) was sent to Turkish dentists from May 5 to 12 May, 2020. The survey comprised questions about dentists' demographic characteristics, their knowledge about COVID-19, stress levels and the measures taken in dental clinics against COVID-19. This study included a total of 1,095 Turkish dentists. The data were expressed as frequency with percentage values for overall variables. Dentists were most familiar with high fever among the symptoms of COVID-19 (99.4%) and 99.2% of them reported that COVID-19 was transmitted with eye, mouth and nasal mucosa contact on surfaces contaminated with the droplets of infected persons. While the stress levels of females were higher than males, the stress levels of dentists with more than 20 years of professional experience were found to be lower. Regarding the precautions to be taken as a preventive measure when working again, 86.6% of the dentists took precautions by increasing daily patient care intervals and only 38.4% of the dentists wore an N95 mask. During this pandemic, knowing the conditions about when the treatments can be applied and the precautions to be taken will shed light on dentistry staff. Current recommendations of national authorities about the coronavirus should be followed.
Citation Count: 0
MARGINAL MICROLEAKAGE OF GLASS IONOMER BASED RESTORATIONS AFTER CONVENTIONAL CAVITY PREPARATION AND ER: YAG LASER IRRADIATION
(Dokuz Eylul Univ inst Health Sciences, 2022) Kaynar, Zeynep Buket; Donmez, Nazmiye; Siso, Seyda Herguner
Purpose: Assessing the microleakage of glass ionomer restorations (GIC) prepared with both conventional and Er:YAG laser techniques in Class V cavities is the purpose of the study.Material and Methods: Twenty teeth with Class V cavities (4mm wide, 3mm high, 3mm deep) were used. Cavities were prepared on the buccal and lingual surfaces of teeth which were randomly separated into four groups. Er:YAG laser was used to prepare cavities in Groups II and IV, conventionally diamond bur was used to prepare cavities in Groups I and III. Then, Groups I and II were restored with conventional GIC (Ketac Molar Easymix, 3MEspe, Seefeld, Germany) and high viscosity GIC with resin coating (EQUIA Fil, GC Dental Co., Tokyo, Japan) to restore Groups III and IV. Samples were stored in distilled water at 37 degrees C for 24 hours before subjecting to thermo-cycling (500 cycles,5 degrees C-55 degrees C). In a chewing simulator, all teeth were exposed to 50.000 cycles. We used 0.5% aqueous basic fuchsin dye to stain the samples and sectioned them bucco-lingually. Scoring dye penetration was made under a stereomicroscope. The data were analyzed by Kruskal-Wallis One-Way ANOVA and Mann-Whitney U tests.Results: While the highest microleakage scores were obtained in the group prepared with Er: YAG laser and restored with conventional GIC the lowest microleakage scores were obtained in the group prepared with Er:YAG laser and restored with high viscosity GIC. When cavities prepared with Er:YAG laser or conventional method were restored with high viscosity GIC, no statistically significant difference was found between them (p> 0.05).Conclusion: High viscosity GIC can be preferred as a restorative material in the restorations of Class V cavities prepared using both conventional and Er:YAG lasers.
Citation Count: 12
Perceptions of dental students towards online education during the COVID-19 pandemic
(Istanbul Univ Press, Istanbul Univ Rectorate, 2021) Gungor, Ayca Sarialioglu; Uslu, Yesim Sesen; Donmez, Nazmiye
Purpose This study evaluated the usage habits, attitudes, and perceptions of undergraduate dental students toward distance (online) learning and identified variables related to those attitudes. Materials and Methods The study included 1,605 undergraduate dental students who participated voluntarily. The data collection tool consisted of a distance learning attitude scale, a questionnaire on personal information, and open-ended questions. The perceptions of dental students to distance education according to the year and type of dental school they attended were evaluated. Results Most students expressed that distance learning in dental courses was not as effective as traditional face-to-face education (59.1%, n=949). While students studying at state universities had a more negative view of distance education, the satisfaction scores of the first-year students were found to be significantly lower than the other students (p < 0.05). Conclusion Dental students were generally unhappy with the interruption of traditional education caused by COVID-19 and having to continue their education online. However, under the circumstances, they saw it as an advantage allowing them to continue their education and avoid a complete suspension.