Browsing by Author "Degirmenci, Beyza Unalan"

Now showing 1 - 8 of 8

Comparison of the Shear Bond Strength of Metal Orthodontic Brackets Bonded To Long-Term Water-Aged and Fresh Porcelain and Composite Surfaces
(Galenos Publ House, 2019) Kaya, Yesim; Degirmenci, Beyza Unalan; Degirmenci, Alperen
Objective: The aim of the present study was to compare the shear bond strength (SBS) of metal orthodontic brackets bonded to long-term water-aged and fresh porcelain and composite surfaces. Methods: One porcelain (Vitadur Alpha (VA)) and three composite (Filtek Ultimate (FU), Tetric EvoCeram (TEC), and Gradia Direct Anterior (GDA)) materials were evaluated in the present study. First, 10 discs from each material were prepared and subjected to the aging procedure for 5 years. Then, for comparison, another 10 discs from each material were prepared as fresh surfaces and stored in distilled water for 24 h. Metal brackets were bonded to the prepared disc surfaces, and after being stored in water for 24 h, they were subjected to shear bond test using a universal testing machine. Adhesive remnant index (ARI) scores were obtained by examining the disc surfaces under a stereomicroscope at 10x magnification. Kruskal-Wallis test was used to compare the aged and fresh groups. Results: Although the difference between the SBS between the aged and fresh groups with VA, FU, and TEC was not significant, the SBS was significantly higher in the fresh group with GDA. With regard to ARI scores, there was no significant difference between the aged and fresh groups with FU and GDA, whereas the ARI scores of the aged groups with VA and TEC were higher. Conclusion: It was concluded that the aged restoration materials have a distinctive influence on the SBS of metal orthodontic brackets.
The Effects of Thickness Changes in Different Composites on Translucency, Opalescence, and Masking Efficacy
(Discovery Publication, 2018) Degirmenci, Beyza Unalan; Degirmenci, Alperen
Objective: The aim of this study is to evaluate the effects of thickness increase in nanohybrid and microhybrid composites on translucency, opalescence and masking efficacy. Material and methods: For this study, a total of 72 composite discs with thicknesses of 1, 1.5 and 2 mm were prepared from nanohybrid and microhybrid composites. Disk measurements were made with the aid of a spectrophotometer and translucency parameter (TP), opalescence (OP-BW) and masking efficacy (ME) were calculated. Results: The decrease in the values of TP and OP-BW and increase in the values of ME were observed with thickness increase in both microhybrid and nanohybrid composites. Moreover, while statistically significant positive correlation was detected between TP and OP-BW, it was also detected that ME and TP and ME and OP-BW were statistically significant between each other but negative correlation was detected. Discussion: The thickness of composite materials directly affects the aesthetic properties of restorative materials.
Effects of Various Antioxidant Pretreatment Modalities on Adhesion To Sound and Caries-Affected Dentin: an in Vitro Study
(Sage Publications india Pvt Ltd, 2021) Degirmenci, Beyza Unalan; Degirmenci, Alperen; Kara, Emine
Aim: Natural antioxidants were offered as the answer of dentin adhesion issue. The aim of this study is to investigate the effects of proanthocyanidin and lycopene as pretreatment agents on the sound and caries-affected dentin surface on microtensile bond strength and microleakage. Materials and Methods: This study was designed as in vitro because of that 84 mandibular molar teeth were collected. Forty-two of the included teeth were carious teeth, while the other 42 were without caries. Sixty of them were used for microleakage and 24 for microtensile bond strength testing and scanning electron microscopy analysis. The samples were divided into six subgroups randomly according to dentin pretreatments: 5% proanthocyanidin, 5% lycopene, and no antioxidant application. After the restorative procedures, samples were attached to the microtensile tester. Samples were subjected to tensile stress in the load cell until they broke at a speed of 0.5 mm per min. Microtensile bond strength (mu TBS) and microleakage test data were analyzed with two-way analysis of variance, Bonferroni correction, and Tamhane's T2 tests. Results: Two-way variance analysis showed that dentin pretreatment applications, dentin substrate, and the interaction between these two parameters had statistically significant effects on mu TBS values (P < .001). There was no difference between dentin pretreatment applications in terms of microleakage scores (P > .05). Conclusion: The application of dentin pretreatment with proanthocyanidin is a successful procedure that increases the bond strength in both dentin substrate, while pretreatment with lycopene in caries-affected dentin reduces it.
Evaluation of Color Changes of Different Resin Cements in Feldspathic Ceramic Crowns After Accelerated Aging: an in Vitro Research
(Sage Publications india Pvt Ltd, 2022) Eskitascioglu, Murat; Akdeniz, Mehmet Serif; Degirmenci, Beyza Unalan
Aims: To evaluate the color changes that occur after accelerated aging in feldspathic ceramic crowns cemented with three different dual-cured resin cements. Materials and Methods: For each of the A2-colored RelyX U200, G-CEM LinkForce, and Panavia V5 cement groups, 45 dies from A2-colored zirconia blocks and 45 crowns from CEREC blocks were prepared. Color measurements after 24 h of cementation (T1) and after cycles of aging of 1750 (T2), 3500 (T3), and 7000 (T4) in the thermal cycle device were made using SpectroShade Micro device. The coordinates of the color were used L*, a*, and b* as base and the color change was calculated with Delta E-00 in determining the color. One-way analysis of variance test was used to compare the times in terms of Delta L*, Delta a*, and Delta b* values. Results: It was found that Delta L* value decreased significantly in period of the T2, T3, and T4 times compared to T1 in all groups (P<.05), whereas the change between period of T2, T3, and T4 times was not significant (P>.05). The Delta a* value increased significantly in the period of T3 and T4 times compared to T1 in the only G-CEM LinkForce group, whereas the Delta b* value increased significantly in the period of T4 time compared to T1 in the only Panavia V5 group. The changes in Delta E-00 values, which were observed in all period of times, were found to be between 0.43 and 1.04, 0.43 and 1.43, and 0.40 and 0.97 in RelyX U200, G-CEM LinkForce, and Panavia V5 groups, respectively. Conclusion: After accelerated aging, it was found that the color of all cements became darker and the G-CEM LinkForce group turned red and the Panavia V5 group turned yellow. However, it was found that the color changes that occurred were within clinically acceptable visible levels.
Evaluation of Gingival Displacement Methods in Terms of Periodontal Health at Crown Restorations Produced by Digital Scan: 1-Year Clinical Follow-Up
(Springer London Ltd, 2021) Degirmenci, Beyza Unalan; Naldemir, Beyza Karadag; Degirmenci, Alperen
The purpose of this clinical study was to compare the effects of the gingival displacement techniques of retraction cord, cordless paste system, and Er,Cr:YSGG laser troughing on the periodontal tissues around the crown restoration produced using a digital scan. This was analyzed by recording the probing depth (PD), plaque index, gingival index (GI), mobility, sensitivity, and bleeding on probing (BOP) index. This study included 60 mandibular 1(st) molars from 52 participants (20 males and 32 females) requiring crown restoration. The margin lines of the crown preparations were placed 1 mm subgingivally. Based on the gingival displacement technique used, the patients were divided into three groups: retraction cord, cordless paste system, and Er,Cr:YSGG laser troughing. A digital scan of the prepared tooth was performed. Follow-up appointments were scheduled at five different times: 1(st) day, 1(st) month, 3(rd) month, 6(th) month, and 1(st) year. Six periodontal indices were used to assess the periodontal health. The chi-square test was used to compare categorical variables depending on the groups. There was a significant difference in the PD, GI, and BOP index scores among the three techniques during the 1-year clinical monitoring (p < 0.001). The PD in the three zones of the buccal surface showed a significant increase with time in the retraction cord and cordless paste system groups (p < 0.001). The highest GI scores were observed in the retraction cord group on the 1(st) day. The Er,Cr:YSGG laser troughing procedure produced lower PD, GI, and BOP index scores as compared to the retraction cord and cordless paste system procedures in the 1-year period.
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.
Evaluation the Effects of Low-Level Laser Therapy on Disc Displacement With Reduction
(Baycinar Medical Publ-baycinar Tibbi Yayincilik, 2020) Tunc, Serap Keskin; Degirmenci, Beyza Unalan; Yayli, Nazli Alpaslan; Aslan, Senol; Akdeniz, Mehmet Serif
Objectives: This study aims to evaluate the effects of additional low-level laser therapy (940 nm GaAIAs) to the routine occlusal splint therapy on maximal mouth opening (MMO), visual analog scale (VAS) scores, and passive mouth opening (PMO). Patients and methods: Between January 2016 and March 2018, a total of 40 patients (10 males, 30 females; mean age 22.35 years; range, 18 to 60 years) with disc displacement with reduction of the temporomandibular joint were included. The patients were divided into two groups. Group 1 (control group, n=20) received routine non-steroidal anti-inflammatory drug (NSAID) therapy and occlusal splint therapy for eight hours per day for a total of three months. Group 2 (laser group, n-20) received NSAID, occlusal splint therapy and 940 nm wavelength diode laser therapy for two sessions per week for a total of four weeks. The MMO, PMO, and VAS scores were recorded before and at one, two, three, four, and 12 weeks after treatment. The joint and muscle examinations were performed. Results: A constant decrease was found in the VAS scores in both groups. At four (p=0.008) and 12 weeks (p-0.003), a statistically significant difference in the VAS scores was observed. At all time points, PMO and MMO scores increased in both groups. The MMO scores were statistically higher in the laser group at all time points (p<0.005). Conclusion: Our study results suggest that short-term low-level laser therapy additional to conventional treatment may yield satisfactory outcomes.
Influence of Surface Treatments on the Bond Strength of Metal Brackets To Cad/Cam Materials and Discoloration After Various Refinishing Procedures Scanning Electron Microscopy and Atomic Force Microscopy Study
(Urban & Vogel, 2023) Tunca, Murat; Degirmenci, Beyza Unalan
Purpose This study evaluated the shear bond strength (SBS) of a metal bracket bonded to three different computer-aided design/computer-aided manufacturing (CAD/CAM) restoration materials pretreated with different surface treatments. In addition, the surface topography and color change of the restorations after debonding with two different tungsten carbide burs were examined. Methods A total of 216 plates were cut from three different CAD/CAM blocks, each of which was divided into three subgroups with different pretreatment methods: (1) acid etching, (2) sandblasting, and (3) laser irradiation. Incisor metal brackets were bonded. The SBS test was performed, and the failure types were classified. Then, samples were randomly divided into two subgroups according to the adhesive removal procedure to be used: a tungsten carbide bur with 12 blades or 24 blades (n = 12). Color change was calculated based on the increment E-00, and surface morphology was evaluated via SEM and AFM analysis. Results The SBS data revealed that the type of CAD/CAM material and the applied surface treatment significantly affected bond strength. The highest SBS values were detected for the Grandio Blocs (VOCO GmbH, Cuxhaven, Germany; 14.3 +/- 4.4 MPa), and the lowest was observed for Cerasmart (GC Europe, Leuven, Belgium; 12.0 +/- 4.0 MPa). The increment E-00 results demonstrated significant differences only as a result of the applied surface treatment. The increment E-00 value in all groups was above the 1.77 threshold. Conclusion CAD/CAM material types and surface treatments affected the bond strength, but the interactions of these factors did not. The chosen surface treatment also significantly affected the increment E-00 after the polishing was done.