ABSTRACT
The aim of this study is to evaluate the surface roughness (SR) and color changes of single-shade and nanohybrid resin-based restorative materials (RBC) after immersion in liquids at different pH values. For RBCs, a total of 120 specimens, 30 for each material, were prepared using 10 mm diameter and 2 mm thick molds. For flowable bulk fill RBC, a total of 40 specimens, 10 for each material, were prepared using 10 mm diameter and 4 mm thick molds (n = 10). After initial color and SR measurements, samples were stored in the liquids for 14 days and all of the measurements were repeated on 14th days. Scanning electron microscopy and atomic force microscopy analyzes were performed in all groups. When SR results are examined; among all liquids, the highest SR value was observed in the Carisma Diamond One (CDO) group, while the lowest SR value was observed in the Omnichroma Flow Bulk (OMF) group (p < .05). When the color changes (ΔE) results are examined; it was observed that CDO group had highest color change and OMF group had the lowest values. It has been observed that among the liquids, the liquids that affect the ΔE values of the materials the most are coffee and cola. When the ΔE values of the subgroups of the materials were examined, there was a statistically significant difference in all subgroups of RBCs (p < .05). While acidic liquids increased the SR of RBCs, coffee more affected the color change of RBCs. RESEARCH HIGHLIGHTS: Clinicians should keep in mind that the RBCs tested may change their surface properties and colors when exposed to various liquids. People who have RBCs should pay attention to the consumption of acidic and highly pigmented liquids.
ABSTRACT
Purpose: The aim of this study is to compare the biocompatibility of two different resin composites after polymerization under two different light sources in three different time periods. Materials and methods: 72 polyethylene tubes polymerized with 2 different resin composites and 2 different light sources (Elipar S10 and Valo ) [Group 1: Kalore Elipar S10 (KE), Group 2: Kalore Valo (KV), Group 3: Essentia Elipar S10 (EE), Group 4: Essentia Valo (EV)] were implanted in the dorsal connective tissue of 18 rats. 24 empty polyethylene tubes [Group 5: (Control group)] were implanted in the dorsal connective tissue of 6 rats. Then, the rats were sacrificed after 7th, 15th and 30th days in each time intervals (n=8). Biopsy samples were stained with H&E and examined for inflammation, necrosis, macrophage infiltrate, giant cell and fibrous capsule criteria. Immunohistochemical staining was performed to evaluate proinflammatory cytokines (IL-1ß, IL-6 and IL-8). Results: When the composite groups and the control groups were compared; the difference was statistically significant for the criteria of inflammation at 7th and 15th days, there was no statistical difference between the time points in terms of fibrous capsule and necrosis. When the composite groups and control groups were evaluated in terms of proinflammatory cytokines; statistically significant differences were found at 7th, 15th and 30th days. Conclusion: All CRs used in this study showed acceptable biocompatibility in the subcutaneous tissues of rats after polymerization with different light sources.
ABSTRACT
The aim of this study is to evaluate the microhardness, relative surface roughness, and elemental changes of resin-based dental restorative materials (RDRMs) after gastric acid treatment. Five different RDRMs (Group 1 [Filtek Z550], Group 2 [Beautifil II], Group 3 [Vertise Flow], Group 4 [Dyract XP], Group 5 [Fuji II LC]) were used. Samples were formed by using plexiglass molds of 10 mm diameter and 2 mm thickness. A total of 50 samples (n = 10) for microhardness tests and a total of 15 samples (n = 3) for scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDX) analysis were prepared. All samples of each group were treated to gastric acid, simultaneously. A Vickers microhardness tester was used to evaluate the microhardness of the upper surfaces of each sample. SEM-EDX system was used for microstructure and elemental composition detection. The SEM-EDX, microhardness and relative surface roughness analysis were made prior to treatment in gastric acid for 14 days and analysis were repeated on the 14th day. As the difference in the microhardness values of RDRMs was compared, the time-dependent variation in all RDRMs was found to be statistically significant. It was observed that a drastic decrease in microhardness values was in Beautifil II, Filtek Z550, Vertise Flow, Fuji II LC, and Dyract XP, respectively. Average decrease rate of microhardness values compared to the initial state can be listed from high to low as Beautifil II (%35.72), Vertise Flow (% 28.88), Fuji II LC (% 21.09), Dyract XP (%17.60), and Filtek Z550 (% 16.58). As a result, in in-vitro conditions gastric acid decreased microhardness while increasing the relative surface roughness of RDRMs.
