scholarly journals Effect of Modeling Resins on Microhardness of Resin Composites

Author(s):  
Ezgi T. Bayraktar ◽  
Pinar Y. Atali ◽  
Bora Korkut ◽  
Ezgi G. Kesimli ◽  
Bilge Tarcin ◽  
...  

Abstract Objectives This study was aimed to determine the effects of modeling resins on the surface microhardness of composites. Materials and Methods Six resin-based composites (Charisma Smart, Estellite Asteria, CeramX-One SphereTEC, Admira Fusion, Filtek Ultimate, and Clearfil Majesty Es-2) and three wetting agents (Modeling Liquid, Composite Primer, and Modeling Resin) were investigated. In all, 240 specimens were prepared, and wetting agents were applied prior to light curing in the experimental groups. After 24 hours, specimens were polished and Vickers microhardness (VHN) values were measured. Statistical Analysis Shapiro–Wilk and two-way analysis of variance (ANOVA) were used for analyses (p < 0.05). Results Both modeling resin and composites were determined to be effective factors (p < 0.001). The control group showed the highest VHN (70.37 ± 7.94), followed by Modeling Liquid (64.68 ± 12.07), Composite Primer (59.84 ± 6.33), and Modeling Resin (58 ± 3.52b; p < 0.001). Filtek Ultimate showed the highest VHN (76.62 ± 9.78c), whereas Charisma Smart (58.87 ± 7.95), and Clearfil Majesty (67.27 ± 2.58) showed the lowest (p < 0.001). Clearfil Majesty–Modeling Liquid (46.62 ± 5.33) and Charisma Smart–Composite Primer (50.81 ± 0.39) combinations showed the lowest VHN, whereas Filtek Ultimate–control (87.15 ± 2.12) and Filtek Ultimate–Modeling Liquid (84.24 ± 3.11) showed the highest (p < 0.001). Conclusion All tested modeling resins decreased VHN value, and the amount of reduction varied among composites and wetting agents. It might be safer not to use wetting agents unless they are necessary.

Author(s):  
Swe Zin AUNG ◽  
Tomohiro TAKAGAKI ◽  
Masaomi IKEDA ◽  
Kosuke NOZAKI ◽  
Michael F. BURROW ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Luca Marigo ◽  
Giuseppina Nocca ◽  
Giulia Fiorenzano ◽  
Cinzia Callà ◽  
Raffaella Castagnola ◽  
...  

The aim of this study was to evaluate the effect of light-curing protocols on two modern resin composites using different air-inhibition coating strategies. This was accomplished by assessing the amount of monomer elution, surface microhardness, and composite discoloration in different storage conditions. A total of 120 specimens were prepared using Filtek Supreme XTE (3M ESPE, Seefeld, Germany) and CeramX Universal (Dentsply DeTrey, Konstanz, Germany). Specimens were light-cured in air as per manufacturer’s instructions or in the absence of oxygen. This latter condition was achieved using three different approaches: (i) transparent polyester strip; (ii) glycerin; (iii) argon gas. Specimens were assessed for release of monomers, Vickers hardness, and discoloration after storage in different solutions. The results were analyzed with ANOVA one-way test followed by Student-Newman-Keuls test. Moreover, multiple comparisons of means were performed using the Student t-test (p<0.05). The amount of monomers released from the tested specimens was very low in all conditions. The presence of oxygen induced some decrease in microhardness. The highest discoloration values, for both materials, were obtained after ageing in red wine. In case finish and polish procedures are awkward to achieve in posteriors composite restoration, light-curing in the absence of oxygen should be considered, especially when performing composite restoration in esthetic areas.


2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Atiyeh Feiz ◽  
Farahnaz Arbabzadeh Zavareh ◽  
Seyed Mohammad Razavi ◽  
Hamid Badrian ◽  
Sepideh Dolatyar ◽  
...  

The aim of the study was to determine and compare the reaction of rat subcutaneous connective tissue to resin composites polymerized with different lights curing and lightening methods. In this in vivo study, 20 mature Wister Albino rats were used. The composite discs, 4 mm in diameter and 2 mm thick, were cured by QTH or LED light curing units with 4 different lightning methods (full power QTH, full power LED, pulse LED, and ramp LED). Five resin composite discs were implanted in each rat, so that 4 of 5 discs for implantation of cured composite discs differently and central one as control without implantation. After sacrificing at 7, 14, 30, and 60 days the inflammatory grade, fibrosis, and necrosis were determined. Freedman and Cochran tests were used to analyze the data using SPSS software ver. 15. The results of the study showed significant differences in inflammation grade and fibrosis among control group and 4 experimental groups at day 14 (P<0.05). In necrosis, there was no significant difference among 4 groups in different times (P>0.05). In conclusion, neither the type of light curing units (LED or QTH) nor the lightening methods can affect the grade of inflammatory reaction.


Author(s):  
Alireza Daneshkazemi ◽  
Mahnaz Ersi

Introduction: An important disadvantage of current dental resin composites is their polymerization shrinkage and production of microleakage. This shrinkage can cause tooth sensitivity, marginal discoloration, and secondary caries. The objective of this study was to review the effective factors on microleakage of methacrylate and silorane composites and compare them with each other. This reviewed article was compiled and searched on library sources and Google scholar, Pubmed, ISI of science database, using the key words “Microleakage, Siloran-Based Composite, Methacrylate-Based Composite, Retentive Groove, Light Curing Technique,” from 1984 -2019. Although it is not yet definitely clear, which methods of layering techniques (oblique, vertical, split) are more suitable, it seems that the layering technique has advantage over the bulkythat can effective in decreasing the shrinkage caused by polymerization and the resulting microlaekage.  It can also be concluded that silorane base composites have less shrinkage, but some factors such as cavity type, cavity extent, cavity margin distance to CEJ, type of silorane base  bonding system are also involves in their microleakage.  It seems the presence of retention grooves in the cavities seems useful, because it increases the bonding area and mechanical retention as well as decreases the marginal shrinkage due to polymerization and the resulting microleakage. Conclusion: Finally, it can be said that microleakage cannot be stopped completely, and more studies, especially clinical studies, should be conducted to show the effects of these cases clinically.


2018 ◽  
Vol 8 (2) ◽  
pp. 144
Author(s):  
Ria Afrianti

This study aims to determine the effect giving of ethylacetate fraction of leather  purple sweet potato (Ipomoea batatas (L.) Lam, on levels of malondialdehyde (MDA) serum in mice hyperglicemia were induced with streptozocin dose of 50 mg/kgBW. Mice were divided into 5 groups, each group consisting of 3 tails, group I is a negative control, group II is a positive control, group III,IV and V is given ethylacetate fraction a dose of 100 mg/kgBW, 300 mg/kgBW, and 600 mg/kgBW. Ethyl Acetate Fraction leather purple sweet potato given orally for 15 days after the animal is declared hyperglicemia and measurement of blood glucose levels on 5, 10, and 15 day after giving test preparation in animal experiments. On the 16 day throughout the mice were taken serum levels measured malondialdehid. The statistical analysis results showed that giving of ethyl acetate fraction of leather purple sweet potato at a dose of 100 mg/kgBW, 300 mg/kgBW, and 600 mg/kgBW can lower blood glucose levels in mice hyperglycemia significantly (p<0.05). Malondialdehid levels on average in each group is 1.35 nmol/ml, 3.00 nmol/ml, 2.72 nmol/ml, 2.20 nmol/ml and 2.61 nmol/ml, the results of statistical analysis showed a decrease in melondialdehid serum levels were significantly (p<0.05), where a dose of 300 mg/kgBW is an effective dose for lowering blood glucose levels followed by decreased levels of malondialdehid which give effect approaching negative control.


2021 ◽  
Vol 10 (11) ◽  
pp. 2355
Author(s):  
Dean Decter ◽  
Nissim Arbib ◽  
Hila Markovitz ◽  
Daniel S. Seidman ◽  
Vered H. Eisenberg

We compared the prevalence of ultrasound signs of adenomyosis in women with endometriosis who underwent surgery to those who were managed conservatively. This was a retrospective study of women evaluated at a tertiary endometriosis referral center who underwent 2D/3D transvaginal ultrasound. Adenomyosis diagnosis was based on the presence of at least three sonographic signs. The study group subsequently underwent laparoscopic surgery while the control group continued conservative management. Statistical analysis compared the two groups for demographics, symptoms, clinical data, and sonographic findings. The study and control groups included 244 and 158 women, respectively. The presence of any, 3+, or 5+ sonographic signs of adenomyosis was significantly more prevalent in the study group (OR = 1.93–2.7, p < 0.004, 95% CI; 1.24–4.09). After controlling for age, for all findings but linear striations, the OR for having a specific feature was higher in the study group. Women in the study group with ≥ 5 sonographic signs of adenomyosis had more than twice the risk of experiencing infertility (OR = 2.31, p = 0.012, 95% CI; 1.20–4.45). Sonographic signs of adenomyosis are more prevalent in women with symptomatic endometriosis who underwent surgery compared with those who continued conservative management. Women with 5+ findings have a significantly increased risk of infertility. Adenomyosis on ultrasound should be considered in the management decisions regarding these patients.


PEDIATRICS ◽  
1957 ◽  
Vol 20 (1) ◽  
pp. 92-97
Author(s):  
Jo-Anne E. Richards ◽  
Richard B. Goldbloom ◽  
Ronald L. Denton

Forty-three full-term infants have been studied with respect to hemolysis of erythrocytes in solutions of hydrogen peroxide and concentrations of bilirubin in the serum. Mean values for concentration of bilirubin in the serum and percentage of hemolysis followed similar patterns in the first few days of life. However, statistical analysis of the data in individual cases showed no significant correlation between the degree of hemolysis in solutions of hydrogen peroxide and the concentrations of bilirubin in the serum. Administration of vitamin E prevented an increase in hemolysis of erythrocytes in solutions of hydrogen peroxide but failed to produce any significant change in concentrations of bilirubin as compared with the control group. The evidence suggests that the relative deficiency of vitamin E which exists in most newborn infants does not play a part in the causation or maintenance of physiologic hyperbilirubinemia. The clinical significance of increased hemolysis of the erythrocytes of the newborn infant in solutions of hydrogen peroxide remains a mystery. Possible approaches to the clarification of this problem are suggested.


2017 ◽  
pp. 71-73
Author(s):  
N.Yu. Bysaha ◽  

The objective: study of hormonal status in pregnant women with benign cervical pathology (CP) in anamnesis. Patients and methods. Clinical and statistical analysis of the hormonal status of 100 women with a history of benign CP pathology has been performed. According to the revealed symptoms of CP during colposcopic examination, women were divided into two groups: 100 pregnant women, in whom colposcopic and cytologically signs of CP pathology were not detected, were included in the control group; and 100 women who had a pathology of CP, entered the main group. Results. The study examined hormonal relationships in the system mother–placenta–fetus, namely the level of hormones such as estriol, progesterone, human chorionic gonadotropin, placental lactogen. Hormonal changes in pregnant women and contribute to reducing the immunoreactivity unwanted stimulation of existing benign hyperplastic background processes in the cervix. Conclusion. Determining functional state placenta is an important factor in the timely diagnosis of disorders in the functioning of the system mother–placenta–fetus. Key words: hormonal status, placenta, uterine cervix, fetoplacental complex.


2020 ◽  
Vol 45 (5) ◽  
pp. 496-505
Author(s):  
CS Sampaio ◽  
PG Pizarro ◽  
PJ Atria ◽  
R Hirata ◽  
M Giannini ◽  
...  

Clinical Relevance Shortened light curing does not affect volumetric polymerization shrinkage or cohesive tensile strength but negatively affects the shear bond strength of some bulk-fill resin composites. When performing shortened light curing, clinicians should be aware of the light output of their light-curing units. SUMMARY Purpose: To evaluate volumetric polymerization shrinkage (VPS), shear bond strength (SBS) to dentin, and cohesive tensile strength (CTS) of bulk-fill resin composites (BFRCs) light activated by different modes. Methods and Materials: Six groups were evaluated: Tetric EvoCeram bulk fill + high mode (10 seconds; TEC H10), Tetric EvoFlow bulk fill + high mode (TEF H10), experimental bulk fill + high mode (TEE H10), Tetric EvoCeram bulk fill + turbo mode (five seconds; TEC T5), Tetric EvoFlow bulk fill + turbo mode (TEF T5), and experimental bulk fill + turbo mode (TEE T5). Bluephase Style 20i and Adhese Universal Vivapen were used for all groups. All BFRC samples were built up on human molar bur-prepared occlusal cavities. VPS% and location were evaluated through micro–computed tomography. SBS and CTS tests were performed 24 hours after storage or after 5000 thermal cycles; fracture mode was analyzed for SBS. Results: Both TEC H10 and TEE H10 presented lower VPS% than TEF H10. However, no significant differences were observed with the turbo-curing mode. No differences were observed for the same BFRC within curing modes. Occlusal shrinkage was mostly observed. Regarding SBS, thermal cycling (TC) affected all groups. Without TC, all groups showed higher SBS values for high mode than turbo mode, while with TC, only TEC showed decreased SBS from high mode to turbo modes; modes of fracture were predominantly adhesive. For CTS, TC affected all groups except TEE H10. In general, no differences were observed between groups when comparing the curing modes. Conclusions: Increased light output with a shortened curing time did not jeopardize the VPS and SBS properties of the BFRCs, although a decreased SBS was observed in some groups. TEE generally showed similar or improved values for the tested properties in a shortened light-curing time. The VPS was mostly affected by the materials tested, whereas the SBS was affected by the materials, curing modes, and TC. The CTS was not affected by the curing modes.


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