European Oral Research最新文献

Purpose: The aim of the present study is to determine the amount of titanium ions released into the artificial salivary medium by modified glass ionomer cement (GIC) doped with 3% and 5% (w/w) titanium dioxide nanoparticles (TiO2-NPs), and to evaluate their antibacterial properties.

Materials and methods: 120 cylindrical discs with a diameter of 4 mm and a height of 6 mm were made with 3% and 5% w/w modified GIC containing TiO2 NPs, divided into two groups of 60, and immersed in a chemically synthesized salivary medium. The samples were quantified over four-time periods: 24 hours, two months, four months, and six months, using inductively coupled plasma mass spectroscopy (ICP-MS), antibacterial properties were evaluated by means of colony forming count (CFU) method.

Results: The amount of titanium ions released from the discs that received 3%(w/w) TiO2 was highest in the first two months, with no significant release at successive intervals. Also, the second group, which included 5% (w/w) TiO2, saw a considerable ion release at every interval, with the second month seeing the maximum release. The levels in the 5% (w/w) group were consistently higher when the two concentrations were compared at each of the four time points, indicating a considerable increase in titanium release and antibacterial property with a concentration increase from 3% to 5%.

Conclusion: 3% and 5% (w/w) concentrations may be considered safe and exhibit significant antimicrobial effect, titanium ions were discharged at higher rates in 5% (w/w) modified GIC containing TiO2-NPs than in 3% (w/w) modified GIC containing TiO2-NPs.

Purpose: This study aimed to evaluate the effects of different polishing protocols on the surface properties and color stability of the polyetheretherketone (PEEK).

Materials and methods: A total of 96 disc-shaped specimens were fabricated from PEEK material and divided into 6 different groups: control (CN), ''Abraso-Starglanz'' polishing paste (A), ''Yildiz'' polishing paste (Y), ''Enhance'' polishing system (EN), ''Super snap'' polishing kit (SS), and silicone polisher (SP). Surface roughness (Ra) were measured with a profilometer and the surface topography was examined under scanning electron microscope. Color differences were measured with a spectrophotometer according to the CIEDE2000 (∆E00) formulation before and after coffee immersion. Data were statistically analyzed with Kruskall-Wallis and Spearman's correlation analysis (p<0.05, p<0.001).

Results: A statistically significant difference was observed between the Ra measurements of the polishing protocols (p<0.001). Ra measurements except A, Y, and SS groups were found to be higher than the clinical acceptable threshold of surface roughness (0.20 μm). In ΔE00 measurements, statistically significant differences were observed between the CN and SP (p=0.041), EN (p=0.001), and A (p=0.002) polishing protocols. No correlation was found between Ra and color stability.

Conclusion: Only in the A, Y and SS polishing protocols, Ra measurements were not found to be risky in terms of acceptable threshold of surface roughness. Polishing protocols have also generally failed to maintain the color stability. Considering the surface roughness and color stability, the ''Abraso-Starglanz'' paste may be suitable method for PEEK material.

Purpose: This study aimed to evaluate gap formation between the tooth surface and restorative material in terms of microleakage by using optical coherence tomography (OCT) for self-etch and selective-etch applications of two different universal and one self-etch adhesives.

Materials and methods: Sixty non-caries, primary molar teeth were divided into six groups; self-etch and selective-etch application ways of two different universal and one self-etch adhesive systems (n:10). After Class-V cavities were prepared, every tooth was distributed randomly in groups to apply adhesion procedure and then, all cavities were restored with polyacid-modified composite resin. Microleakage was evaluated by measuring the gap between the tooth surface and restoration by a blind researcher with Image J Software from OCT images. During statistical analysis, the significance level was accepted as p<0.05.

Results: According to the statistical analysis of the measurements obtained by Image J Software, selective-etch groups showed less gap formation than self-etch groups for each tested adhesive (p<0.05), and self-etch adhesive without etching showed significantly highest gap formation among all groups (p<0.05).

Conclusion: Universal adhesives with a selective-etching step might be preferred over self-etch adhesives for long-lasting polyacid-modified composite resin restorations in primary teeth. However, obtained results should be considered with another prospective clinical study for long-term prognosis.

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-1β, 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.

Purpose: The purpose of the study was to investigate the impact of repolishing procedures on the color change of bulk-fill resin composites after being exposed to coffee.

Materials and methods: Four bulk-fill resin composites (Filtek One bulk-fill, Tetric EvoCeram bulk-fill, Admira Fusion x-tra bulk-fill, Grandio SO x-tra bulk-fill) were tested. Sixty samples were prepared with each resin composite and were randomly divided into two groups: first one received the one-step polishing system (Optragloss) and the other group received the two-step polishing system (Nova Twist) (n=30). After being kept in coffee for 12 days, the samples were divided into three subgroups according to repolishing: one-step repolishing group, two-step repolishing group, and non-repolishing group (n=10 for each). Color measurements of the resin composite samples were determined with a spectrophotometer. The difference in color change was calculated using the CIEDE 2000 color formula. The data were analyzed using three-way ANOVA and Tukey test.

Results: Among composite materials, Filtek One bulk-fill (1.84 ± 0.98) less color change was observed compared to others (p<0.001). In terms of polishing systems, Optragloss (2.96 ± 1.51) showed significantly greater color change than Nova Twist (2.21 ± 1.07) (p<0.001). The non-repolishing group (3.78 ± 1.25) presented significantly greater color change than the Nova Twist sytem (1.49 ± 0.61) and Optragloss system (2.50 ± 1.01) (p<0.001).

Conclusion: The repolishing process reduced discoloration. A two-step repolishing system results in less color change compared to a one-step repolishing application. In polishing systems containing diamond particles, increasing the number of steps can contribute to color stability.