Light activated resin-based composites are the most accepted and used materials among clinicians. The aim of this study is to determine the amount of residual monomer released from nanofiller composite resins for different polymerization times and storage periods in vitro. To this purpose, Tetric Ceram (Ivoclar, Liechtenstein), Clearfil Majesty Posterior (Kuraray, Japan), Grandio (VOCO, Germany), and Filtek Ultimate Universal (3M, USA) were used as nanofiller resin composites samples. Four groups ( n = 40 , diameter: 5 mm, thickness: 2 mm) of each material were fabricated, and each group was exposed to three different polymerization time (10, 20 and 40 sec). High-performance liquid chromatography (HPLC) was used to measure the amount of monomers released over 1, 15, and 30 days. The highest amount of monomer release was seen in Tetric EvoCream composite, while the least monomer release was seen in Clearfil Majesty composite. Regardless of the polymerization time, material, or storage period, the highest amount of eluted monomer was Bis-GMA. It is observed that there is no statistically significant difference between various polymerization times. Monomer release reached its highest level on the 15th day and decreased on the 30th day for all composites. Polymerization time did not affect the monomer release from the composites, but the type of the monomers and concentration of the filler used in the composites affected the amount of released monomers. The use of TEGDMA (co)monomer reduced the monomer release.
Objective:The aim of this study was to evaluate the change in surface hardness of silorane-based composite resin (Filtek Silorane) in time and compare the results with the surface hardness of two methacrylate-based resins (Filtek Supreme and Majesty Posterior).Materials and Methods:From each composite material, 18 wheel-shaped samples (5-mm diameter and 2-mm depth) were prepared. Top and bottom surface hardness of these samples was measured using a Vicker's hardness tester. The samples were then stored at 37°C and 100% humidity. After 24 h and 7, 30 and 90 days, the top and bottom surface hardness of the samples was measured. In each measurement, the rate between the hardness of the top and bottom surfaces were recorded as the hardness rate. Statistical analysis was performed by one-way analysis of variance, multiple comparisons by Tukey's test and binary comparisons by t-test with a significance level of P = 0.05.Results:The highest hardness values were obtained from each two surfaces of Majesty Posterior and the lowest from Filtek Silorane. Both the top and bottom surface hardness of the methacrylate based composite resins was high and there was a statistically significant difference between the top and bottom hardness values of only the silorane-based composite, Filtek Silorane (P < 0.05). The lowest was obtained with Filtek Silorane. The hardness values of all test groups increased after 24 h (P < 0.05).Conclusion:Although silorane-based composite resin Filtek Silorane showed adequate hardness ratio, the use of incremental technic during application is more important than methacrylate based composites.
Aim. The purpose of this study was to compare the in vitro efficacy of calcium hypochlorite (Ca[OCl]2) and sodium hypochlorite (NaOCl) associated with sonic (Vibringe) irrigation system in root canals which were contaminated with Enterococcus faecalis. Material and Methods. The root canals of 84 single-rooted premolars were enlarged up to a file 40, autoclaved, inoculated with Enterococcus faecalis, and incubated for 21 days. The samples were divided into 7 groups according to the irrigation protocol: G0: no treatment; G1: distilled water; G2: 2.5% NaOCl; G3: 2.5% Ca(OCl)2; G4: distilled water with sonic activation; G5: 2.5% NaOCl with sonic activation; and G6: 2.5% Ca(OCl)2 with sonic activation. Before and after decontamination procedures microbiological samples were collected and the colony-forming units were counted and the percentages of reduction were calculated. Results. Distilled water with syringe irrigation and sonic activation groups demonstrated poor antibacterial effect on Enterococcus faecalis compared to other experimental groups (p < 0.05). There was no statistically significant difference between syringe and sonic irrigation systems with Ca(OCl)2 and NaOCl. Conclusion. The antimicrobial property of Ca(OCl)2 has been investigated and compared with that of NaOCl. Both conventional syringe irrigation and sonic irrigation were found effective at removing E. faecalis from the root canal of extracted human teeth.
Background:The aim the study to compare the effects of pre-operative air-powder polishing and rubber-cup prophylaxis on tooth bleaching. Methods: 23 subjects suffering from discoloration, were enrolled in a randomized controlled split mouth experimental study. Before bleaching, air powder polishing (APP) and rubber-cup polishing (RCP) techniques were applied on either side of the mouth. A 40% hydrogen peroxide bleaching agent applied two 15-minute applications for in-office bleaching. The tooth bleaching effects assessed immediately after and 1 week.Results: There were no significant differences between prophylaxis groups with respect to all color parameters (∆ L, ∆a, ∆b, ∆SGU, ∆Eab, ∆ E00) at immediate period (p>0,05). At 1 week assessment period there were no significant differences between prophylaxis groups with respect to all color parameters (p>0,05) except delta E00 (p<0,05). Conclusions:Two prophylaxis techniques produced similar efficacy in bleaching treatment and the APP technique produced higher levels of color changes.
Bu çalışmanın amacı posterior restorasyon için üretilen yeni mikrohibrit bir kompozitin mikrosertlik, dönüşüm derecesi ve Bis-GMA salımını sıkça kullanılan mikrohibrit bir kompozit materyal ile karşılaştırmaktır. GEREÇ VE YÖNTEM: Bu çalışmada mikrohibrit doldurucu içerikli yeni üretilmiş (NOVA Compo-HS, Imicryl, Konya, Türkiye) ve piyasada bulunan mikrohibrit doldurucu içeren başka bir kompozit rezin materyeli (Filtek Z-250, 3M ESPE, St. Paul, MN, ABD) kullanıldı. Her bir materyalden silindir şeklinde (2x2x2 mm boyutlarında) 20'şer örnek hazırlandı. Her materyal için hazırlanan 20 örnekten 10 adetinde salınan Bis-GMA miktarı yüksek performanslı sıvı kromatografisi (HPLC) (Shimadzu, Model SPD 20A, Shimadzu Corporation, Kyoto, Japonya) ile analiz edildi. Her materyal için geri kalan diğer 10 örneğin Vickers yüzey mikrosertlik dereceleri ölçüldü ve polimerizasyon derinliği Vickers sertlik oranı hesaplanarak değerlendirildi. İstatistiksel analizler bağımsız gruplar t-testi ile yapıldı. BULGULAR: NOVA Compo-HS ve Filtek Z250 arasında üst ve alt yüzeylerde kaydedilen sertlik değerlerinde istatistiksel bir fark olduğu görüldü (p<0.001). NOVA Compo-HS ve Filtek Z250 kompozitlerine ait Bis-GMA salım miktarı ortalama 1.28 mg/L ve 0.78 mg/L idi. Gruplar arasında istatistiksel olarak fark vardı (p<0.001). SONUÇ: Mikro dolduruculu yeni kompozit rezin materyal olan NOVA Compo-HS, mekanik özellikleri (yüzey mikrosertlik dereceleri ve alt/üst yüzeyin Vickers mikrosertlik oranı) bakımından diğer mikro dolduruculu kompozit kadar yeterli bulunmadı. NOVA Compo-HS kompozitten salınan Bis-GMA monomer miktarı, Filtek Z250'ye göre daha fazlaydı.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.