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Purpose: Construction of the orthodontic bracket promotes food accumulation, which is the cause of plaque formation. Modern trends in the design of adhesive orthodontic types of cement focus on the ability to release cariostatic fluoride ions. One of the methods is to incorporate the material with fluorapatite nanoparticles. The aim of the study was to determine the fluoride release capacity of orthodontic cement doped with nanosized fluorapatite in selected media and solution pH over a 12-week period. Methods: A commercial light-curing two-component orthodontic cement GC Fuji Ortho®LC was modified by adding nanofluorapatite at 2% or 5% by weight. Each of the three groups (5 samples in 9 different media of varying ionic composition and pH). Fluoride determination was performed at 18-time intervals. Results: The largest amount of fluoride is released in the first hour of incubation of all samples. Incorporating cement with 5% w/w nFAp significantly increases the ions released. Low pH and artificial saliva are rich in calcium cations promote significantly lower fluoride detection, which is associated with the formation of CaF2 conglomerates image, which confirms the erosion of the surface layer to be responsible for the ability to release the largest amounts of fluoride ions in an acidic environment. Conclusions: The selection of experimental media for studying the fluoride release capacity of biomaterials is important in terms of the results achieved. The nanofluorapatite content correlates with the amount of fluorine released. Some limitations of the current research require further studies. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine a short-term fluoride ions release from selected materials - resin-modified glass ionomer -Vitremer (3M ESPE) and nanohybrid universal composite - Tetric EvoCeram (IvoclarVivadent). Release of fluoride ions [μg/mm²/h] from Tetric EvoCeram and Vitremer into nine environments (artificial saliva - AS, deionized water and 0.9% NaCl) differing in composition of the solution and pH was determined. Six samples were prepared for each solution. In the short-term study, the measurements were taken after 1, 3, 24, 48, 72 and 168 hours. The cumulative values as well as levels of fluoride ions released at concrete time intervals were compared. Within 7 days (168 hours), both materials showed variable levels of fluoride ions release. The highest value of fluoride ions release from nanohybrid Tetric EvoCeram material was reported in deionized water (8) after 24 hours (1.550 ± 0.014 [μg/mm²/h]) and the lowest value was read in the artificial saliva AS pH 7.5 (5) after 1 hour (0.022 ± 0.001 [μg/mm²/h]). What's more, the highest value of F- release from Vitremer was found in deionized water (8) after 168 hours of immersion (24.021 ± 2.280 [μg/mm²/h]) and the lowest value was in the artificial saliva AS (without Ca2+) pH 4.5 (6) (0.303 ± 0.249 [μg/mm²/h]) after 168 hours. Cumulated release of F- after 7 days was notably higher from resin-modified glass ionomer material - Vitremer in all artificial saliva solutions (1-7) which imitated the environment of oral cavity. Therefore, we can assume that Vitremer has better remineralization potential and it may constitute a more effective method of tooth decay prevention. [ABSTRACT FROM AUTHOR]

Diphosphate compounds (KYP2O7) co-doped with Yb3+ and Er3+ ions were obtained by one step urea assisted combustion synthesis. The experimental parameters of synthesis were optimized using an experimental design approach related to co-dopants concentration and heattreatment as well as annealing time. The obtained materials were studied with theinitial requirements showing appropriate morphological (X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM)) and spectroscopic properties (emission, luminescence kinetics). Moreover, the effect of Er3+ and Yb3+ ions doped KYP2O7 on morphology, proliferative and metabolic activity and apoptosis in MC3T3-E1 osteoblast cell line and 4B12osteoclasts cell line was investigated. Furthermore, the expression of the common pro-osteogenic markers in MC3T3-E1 osteoblast as well as osteoclastogenesis related markers in 4B12 osteoclasts was evaluated. The extensive in vitro studies showed that KYP2O7 doped with 1 mol% Er3+ and 20 mol% Yb3+ ions positively affected the MC3T3-E1 and 4B12 cells activity without triggering their apoptosis. Moreover, it was shown that an activation of mTOR and Pi3k signaling pathways with 1 mol% Er3+, 20 mol% Yb3+: KYP2O7 can promote the MC3T3-E1 cells expression of late osteogenic markers including RUNX and BMP-2. The obtained data shed a promising light for KYP2O7 doped with Er3+ and Yb3+ ions as a potential factors improving bone fracture healing as well as in bioimaging (so-called in theranostics). [ABSTRACT FROM AUTHOR]