Maria Antoniades-Halvatjoglou

Bio: Maria Antoniades-Halvatjoglou is an academic researcher from Aristotle University of Thessaloniki. The author has an hindex of 1, co-authored 1 publications receiving 21 citations.

Effect of extraction media and storage time on the elution of monomers from four contemporary resin composite materials

Abstract: Introduction: The purpose of this study was to examine the effect of different extraction media, including culture media, as well as storage times on the elution of monomers from modern dental composites. Materials and Methods: Four contemporary composite materials were tested: (a) Clearfil Majesty Esthetic (Kuraray), (b) Esthet X (DENTSPLY), (c) Filtek Silorane (3M ESPE), and (d) Admira (Voco). Forty-eight specimens were made. The specimens were stored in 1 ml of (a) artificial saliva, (b) Dulbecco`s Modified Eagle Medium (DMEM), (c) DMEM plus 10% fetal bovine serum (FBS), and (d) ethanol 75%. The specimens were analyzed after 24 hours and after 1 week of storage. HPLC Liquid Chromatography was performed to analyze the extracted solutions. The statistical package SPSS 18 was used for the statistical analysis of the results. Results: All the materials tested released monomers that were consistent with the base composition of their resin matrix. Bisphenol-A (BPA) was detected in Clearfil Esthetic and EsthetX when ethanol 75% was used for storage. TEGDMA was released at a faster rate compared to the other monomers with most of the monomer eluted in the first 24 hours. The effect of storage solution and storage time on the elution of the same monomers varied between materials. Conclusions: There was a significant effect of time, storage solution, and material on the elution of the detectable unbound monomers. Unbound monomers were detected in culture media, which may lead to false-negative results in cytotoxicity tests of resin composite materials. BPA was detected in two of the tested materials.

Color stability of nanohybrid resin-based composites, ormocers and compomers

Abstract: The aim of this study is to evaluate the color stability of two nanohybrid resin-based composites, two organic modified ceramic resin composites (ormocers) and a compomer, following their immersion during 4 weeks in four usual drinks. Forty discs of each of the following materials were prepared: GrandioSO (GR), Esthet X (EX), Dyract EXTRA (DY), Ceram X duo (CX), and Admira Fusion (AD). The discs were polished and stored in distilled water during 24 h at 37 °C. Color according to the CIEL*a*b* scale was recoded. Ten randomly selected samples of each material were immersed in red wine (RW), coffee (CF), cola (CK), and distilled water (DW). The color was recorded after 1, 7, 21 and 28 days of immersion. The ΔE values between the baseline color and each of the study timepoints were calculated. The data were analyzed based on the Kruskal-Wallis test, Wilcoxon test, and Mann-Whitney U test. After 1 day of immersion, all the materials showed ΔE > 3.3, except EX, CF, and CX in CK. RD was the most staining beverage (ΔE 15.36 to 31.09). EX and CX were significantly less stained than the rest of the materials (p < 0.05). All the staining solutions produced darkening beyond clinically acceptable limits. EX and CX were the materials who experimented less staining, followed by GD. AD and DY were the materials more stained. RW was the drink that produced more staining, followed by CF and CK. After 24 h of immersion in all the solutions, equivalent to 1 month of exposure in the mouth, the evaluated materials showed clinically unacceptable ΔE values.

Color of bulk-fill composite resin restorative materials.

Abstract: Objective To evaluate the color stability of novel bulk-fill composite resins. Materials and Methods Color measurements of a nanohybrid composite resin (Z550) and 3 bulk-fill composite resins (BLK, AFX, XTF; n = 45) were performed before polymerization. After polymerization, color measurements were repeated and specimens were immersed in distilled water or red wine, or coffee. Color change [CIEDE2000 (ΔE00)] was calculated after 24 h, 1 and 3 weeks. Data were analyzed with Kruskal-Wallis, Mann-Whitney U and Wilcoxon tests (α = 0.05). Results Color changes observed after polymerization were significant for all groups. Color changes observed in distilled water for Z550 and AFX were significant. Color changes after stored in red wine and coffee were significant for all groups. Bulk-fill composite resin color change increased over time for all groups in red wine and coffee (P < .05). Conclusion Polymerization significantly changed the color of nanohybrid composite resin and bulk-fill composite resins. AFX had the highest color change in distilled water. The color of tested bulk-fill composite resins significantly changed after immersion in beverages and over time. Color change observed with the nanohybrid composite resin after 1 week was stable. CLINICAL SIGNIFICANCE Clinicians should keep in mind that tested composite resins may change color when exposed to water and significantly change color immediately after they are polymerized. In addition, the color change continues over time should the patient is a coffee and/or red wine consumer.