Browsing by Author "Degirmenci, A."

Now showing 1 - 7 of 7

Aesthetic Rehabilitation for Anterior Teeth of Dental Fluorosis With Direct Composite Veneers
(Wolters Kluwer Medknow Publications, 2023) Degirmenci, A.; Balousha, J. K. M.; Pehlivan, I. E.
Intrinsic discoloration can be formed due to many reasons, and by clinical evaluation and history from the patient, the exact cause of the discoloration can be known and one of the reasons that can make the intrinsic discoloration is the high level of fluoride intake. Two siblings had come to the Department of Restorative Dentistry clinics; they had the same compliance which is severe dental fluorosis, caries, and malocclusion of their teeth. What is interesting and worrying is that some patients with severe dental fluorosis show higher levels of caries, which can be explained as the enamel becoming porous with severe fluorosis. The possible treatment options were discussed with the patients. According to their financial concern and their desire to get their teeth done as soon as possible, the use of direct composite veneer for the treatment of anterior teeth was decided. Long-term clinical trials are required to assess the efficacy of various treatment options for fluorosis of different severity.
Effects of Er,cr:ysgg Laser on Repair Bond Strength of 5-Year Water-Aged and Non-Aged Cad/Cam Ceramics
(John Wiley and Sons Inc, 2022) Unalan Degirmenci, B.; Degirmenci, A.; Karadag Naldemir, B.
The aim of this study is to examine the repair bond strength of three different 5-year water-aged and non-aged computer-aided design/computer-aided manufacturing (CAD/CAM) ceramics (leucite-reinforced, lithium disilicate, and feldspathic ceramic) on which four different surface treatments (bur-grinding, sandblasting, acid-etching, and laser irradiation) have been applied with composite resin. Note that 360 ea. samples have been attained from CAD/CAM blocks. Each CAD/CAM ceramic has been randomly separated into two sub-groups depending on aging procedure. The designed 5-year water-aged and non-aged samples have been separated into four sub-groups. Ceramic surfaces were repaired then the samples have been placed into shear test device. Three-way variance analysis has been used in the comparison of the repair bond strengths depending on the ceramic type, surface treatment, and aging. Results have revealed that the repair bond strength values show differences depending on CAD/CAM ceramic type, surface treatment, and the aging of the surface (p <.001). While the aged and laser-irradiated feldspathic CAD/CAM ceramics showing the highest shear bond strength, the lowest shear bond strength values were in aged and bur-grinded feldspathic CAD/CAM ceramics. Irradiation with erbium chromium: yttrium scandium gallium garnet (Er,Cr:YSGG) laser has significantly increased the repair bond strength in leucite-reinforced and feldspathic CAD/CAM ceramics, acid-etching is suggested surface treatment for the lithium disilicate CAD/CAM ceramics. © 2021 The American Ceramic Society.
Effects of Er,cr:ysgg Laser Surface Treatments and Composites With Different Viscosities on the Repair Bond Strength of Cad/Cam Resin Nanoceramic
(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Degirmenci, A.; Unalan Degirmenci, B.
This study aims to evaluate the repair micro-shear bond strength of the CAD/CAM resin nanoceramic block treated using four different surface treatments and composite resins of different viscosities. For the current study, 96 samples with dimensions of 14 × 12 × 2 mm were obtained from a CAD/CAM resin nanoceramic block (Cerasmart) with a low-speed precision cutting saw under water cooling. The relevant samples were randomly divided into four groups according to the surface treatment processes: grinding with diamond bur, aluminum oxide airborne-particle abrasion, long-pulse laser, and short-pulse laser. Following silane application, universal adhesive was applied to all surface-treated samples and cured with an LED for 10 s. The samples prepared for the repair procedure were divided into two subgroups (microhybrid composite and injectable composite) according to the viscosity of the repair material to be used (n = 12). After the repair procedure, care was taken to keep the samples in distilled water in an incubator at 37 °C for 24 h. The repair micro-shear bond strength values (μSBSs) of CAD/CAM resin nanoceramic-composite resin complexes were tested. In addition, randomly selected samples from each group were examined with a scanning electron microscope to evaluate the surface topography after both surface treatments and the micro-shear bond strength test. Data were analyzed by two-way ANOVA and Bonferroni test. It was determined that the surface treatment preferred in the repair protocol significantly affected the μSBS value (p < 0.001). While the highest μSBS value was obtained with the short-pulse laser airradiation group, the lowest μSBS values were found in samples with long pulse laser irradiation. However, samples grinded with a bur and airborne-particle abrasion showed similar μSBS values (p > 0.05). The preferred composite viscosity in the repair procedure has a significant effect on the μSBS value (p < 0.001). However, the interaction between the surface treatment and the viscosity of the repair composite does not affect the μSBS values in a statistically significant way (p = 0.193). It may be recommended to clinicians to repair CAD/CAM resin nanoceramic restoration surfaces with injectable composites or after treatment with short-pulse lasers. © 2024 by the authors.
Effects of Polishing Procedures on Optical Parameters and Surface Roughness of Composite Resins With Different Viscosities
(Japanese Society for Dental Materials and Devices, 2023) Degirmenci, A.; Pehlivan, I.E.; Unalan Degirmenci, B.
The aims of this study were to evaluate the optical properties of flowable and injectable composites after polishing, such as translucency (translucency parameter [TP], TP00), opalescence (OP-BW), chroma (C*ab), refractive index (RI), and change in surface roughness (Ra, Rz). Ninety disc-shaped samples were prepared from micro-hybrid, flowable, and injectable composites and divided into 3 groups according to the polishing systems (n=10). The RI was measured with an Abbe refractometer, and optical measurements were performed with a spectrophotometer. The surface roughness was measured with a two-dimensional profilometer. Data were analyzed with the generalized linear model method and two-way analysis of variance. The results showed that the polishing procedure did not significantly impact the RI (p=0.987). Injectable composite had the highest translucency (TP=28.67; TP00=13.49) and opalescence (OP-BW=13.11); showed the lowest C*ab value (17.95). Also, the effects of the composite type and polishing procedure on surface roughness were statistically significant (p=0.047 and p<0.001). © 2023, Japanese Society for Dental Materials and Devices. All rights reserved.
Evaluation the Effect of Different Antioxidants Applied After Bleaching on Teeth Color Stability
(Universidade Estadual Paulista, Institute of Science and Technology of Sao Jose dos Campos, 2020) Degirmenci, A.; Kara, E.; Degirmenci, B.U.; Ozcan, M.
Objective: Vital bleaching is a popular treatment option for discolored teeth; but at post-treatment stage, loss of adhesion is highly reported. Literature focused on antioxidant application for the answer of this issue. The aim of this study was to compare the effects of six different antioxidants on color stability of bleached teeth. Material and Methods: This study included total of 84 extracted intact non-carious lower incisors. 35% hydrogen peroxide was applied on the labial surfaces of specimens in accordance with manufacturer’s instructions. The bleached teeth were divided into 7 groups. No antioxidants were applied to the control group. For the experimental groups, the following antioxidants were applied for 10 minutes each: 5% proanthocyanidin, 5% sodium ascorbate, 5% lycopene, %5 green tea, %5 white tea and %5 α-tocopherol. CIE L*, a* and b* values of the teeth were measured by a spectrophotometer. One-way ANOVA was used to determine the differences among the groups. Multiple comparisons were examined with Tukey HSD. Results: The one-way ANOVA test revealed a statistically significant difference between the groups (p<0.005). Highest color change was observed in lycopene group and the lowest in green tea group. Conclusion: Proanthocyanidin, white tea and green tea could be considered as post-bleaching antioxidant alternatives based on their herbal nature. © 2020, Universidade Estadual Paulista, Institute of Science and Technology of Sao Jose dos Campos. All rights reserved.
The Influence of Thermocycling and Ultraviolet Aging on Surface Characteristics and the Repair Bond Strength of Cad/Cam Resin Nanoceramics
(Multidisciplinary Digital Publishing Institute (MDPI), 2025) Unalan Degirmenci, B.; Degirmenci, A.; Seyfioglu Polat, Z.
Background: The durability of computer-aided design/computer-aided manufacturing (CAD/CAM) resin nanoceramics in the oral environment is influenced by aging factors such as thermocycling and ultraviolet (UV) exposure. This study investigates the impact of these aging processes on surface characteristics and repair bond strength. Methods: CAD/CAM resin nanoceramic samples were divided into the following five groups: control (non-aged), 1-year and 5-year thermocycling, and 1-year and 5-year UV aging (n = 12). For the thermocycling procedure, the parameters employed were a temperature range of 5–55 °C with dwell times of 20 s per bath and 10,000 and 50,000 cycles; for the ultraviolet aging process, the parameters were established at a wavelength of 340 nm, an intensity of 0.55 W/m², and durations of 300 h and 1500 h. Surface roughness, microhardness, and repair bond strength were analyzed through profilometry, Vickers microhardness testing, and shear bond strength assessment, respectively. SEM, AFM, and XRD analyses were performed for structural evaluation. Results: Both thermocycling and UV aging significantly increased surface roughness (p < 0.001) while reducing microhardness and repair bond strength (p < 0.001). UV aging had a more pronounced effect, particularly after five years, leading to the highest surface roughness (Ra: 61.77 μm; Rz: 271.57 μm) and lowest microhardness properties (63.13). EDAX analysis indicated matrix degradation and an increase in inorganic filler exposure. Conclusions: Aging significantly affects the surface characteristics of CAD/CAM resin nanoceramics, with UV aging exhibiting the most detrimental impact. These findings highlight the necessity of considering long-term material stability in dentistry. © 2025 by the authors.
Long-Term Effect of Acidic Beverages on Dental Injectable Composite Resin: Microhardness, Surface Roughness, Elastic Modulus, and Flexural Strength Patterns
(Springer, 2022) Degirmenci, A.; Degirmenci, B. U.; Salameh, M.
The purpose of this study is to evaluate the effects of different acidic beverages on the surface roughness, microhardness, flexural strength, and elastic modulus of microhybrid, bulk-fill, and injectable composites and the correlations between them. Microhybrid, bulk-fill, and injectable composites were used in this study. One hundred and thirty-five disk-shaped samples were prepared for the microhardness test and the surface roughness measurements, and 675 rectangular prism-shaped samples were prepared for elastic modulus and flexural strength measurements. In each sample, the initial surface roughness, microhardness, flexural strength, and elastic modulus were measured and then randomly divided into three groups (n = 15) in preparation for the immersion procedure in coke, orange juice, and artificial saliva. Relevant measurements were repeated on the first day, first week, first month, and first year after the immersion procedure was performed with each beverage. Moreover, the effects of the beverage on surface morphology were evaluated by scanning electron microscopy at the relevant control times. A three-way analysis of variance was used to compare microhardness, surface roughness, flexural strength, and elastic modulus measurement values according to the material, beverage, and immersion cycle, and Tukey's test was used for multiple comparisons. Spearman's rho correlation coefficient was used to examine relationships between parameters. The significance level was p< 0.05. Statistically significant effects were found on the surface roughness values of the materials, beverages, immersion cycle times, as well as the interactions among these parameters (p< 0.001). The highest surface roughness value of 5.28 was obtained in the injectable composite group, which was exposed to a one-year coke immersion cycle. After the immersion cycle, a significant decreasing trend in the microhardness value was detected in all materials (p< 0.001). It was determined that the injectable composite had the highest flexural strength value (173.6 MPa). The lowest flexural strength value was determined to be in the microhybrid composite group (92.9 MPa) before the immersion procedure. Moreover, a significant decrease was observed in the flexural strength and elastic modulus values of all composite groups that were subjected to the immersion cycle with coke, while this change was minimal in artificial saliva. The injectable composite exposed to short- and long-term immersion cycles exhibited a flexural strength value above ISO 4049/2019 standards, which is promising for clinical use.