Browsing by Author "Degirmenci, Alperen"

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Can Wheel Polishers Improve Surface Properties and Color Stability of Monochromatic Resin Composites
(Bmc, 2024) Turkun, Lezize Sebnem; Canevi, Cankut; Degirmenci, Alperen; Boyacioglu, Hayal
Background: To overcome the color layering procedure, monochromatic resin composites have been introduced. However, little is known about their polishability, gloss and color stability. This study aimed to investigate the surface roughness, gloss, and color change of monochromatic resin composites polished with wheel systems after being immersed in coffee. Materials and methods: Omnichroma, Zenchroma, Essentia Universal, Charisma Diamond One and NeoSpectra ST were used to obtain 120-disc samples of 8 x 2 mm. Only one side of the sample was polished with Twist Dia (TWD) or Nova Twist (NOV). The samples were examined for surface roughness, gloss, and color (Delta E and Delta E-00) before and after 7 days of immersion in coffee and subsequent repolishing. The discs were examined via SEM. Surface roughness and gloss values were analyzed using ANOVA, Tukey and Pearson correlation tests. Delta E and Delta E00 values were evaluated using T tests, multivariate ANOVA, and Dunnett's post-hoc tests. Results: For TWD groups, the smoothest material was Omnichroma (p < 0.05), while for NOV groups, it was Omnichroma and Zenchroma. Omnichroma was the glossiest, while Charisma Diamond One was the least glossy. In TWD groups, Charisma Diamond One and Essentia Universal were the most discolored, while Zenchroma and Omnichroma were the least. For NOV groups, Essentia Universal and Charisma Diamond One were the most discolored, while NeoSpectra ST, Omnichroma and Zenchroma were the least. After repolishing, Charisma Diamond One did not reach the level of Delta E < 2, while the other groups showed values below. Color evaluation with the CIELab and CIEDE2000 systems revealed similar results for the TWD groups after post-staining. Conclusions: Smooth and glossy surfaces could be achieved with the wheel system regardless of the composite resin. Repolishing after discoloration ensures that the color recovery is below the acceptable limit. Color evaluations with CIELab and CIEDE2000 yielded similar results.
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 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.
Long-Term Follow-Up of Enamel Color Changes After Treatment With Fixed Orthodontic Appliances
(Mosby-elsevier, 2018) Kaya, Yesim; Alkan, Ozer; Degirmenci, Alperen; Keskin, Siddik
Introduction: The aim of this study was the long-term follow-up of enamel color changes observed in the middle third of buccal tooth surfaces after treatment with fixed orthodontic appliances. Methods: The study included 120 maxillary central and lateral incisors and canines of 20 subjects who had fixed orthodontic treatment. The Spectro Shade Micro device (MHT, Verona, Italy) was used to evaluate the color changes of the teeth. Measurements were made from the middle third of the buccal surfaces of the teeth after fixed orthodontic treatment and in month 3, month 6, and year 1 of the retention phase. The Commission Internationale de I'Echairage L* a* b* system that expresses the color coordinates in L*, a*, and b* symbols was used to determine the tooth color, and Delta E values between the time periods were calculated. Repeated measurement analysis of variance was used in evaluating the color changes. Results: The increases in Delta L values at 3 months, 6 months, and 1 year after treatment were statistically significant, whereas they were not statistically significant from months 3 to 6, month 3 to year 1, or month 6 to year 1. The decrease in Delta a and the increase in Delta b values were not statistically significant. Delta E values at all time periods were statistically significant within themselves, and the greatest change was observed 1 year after treatment. Delta E values were 1.52 to 3.57, and a visible but clinically acceptable color change occurred. Conclusions: In the first 3 months, there was a significant increase in the lightness of the tooth color.