Chemical Changes of Enamel Produced by Sodium Fluoride, Hydroxyapatite, Er:YAG Laser, and Combined Treatments

Occlusal pits and fissures of permanent molars are considered to have higher risk of developing caries. Enamel demineralization can be prevented by applying remineralizing agents, and their absorption increases with prior irradiation. This work evaluates the chemical changes produced by treating occlusal surfaces with sodium fluoride (NaF), hydroxyapatite-NaF-xylitol (HA-NaF-X), Er:YAG laser irradiation (L), and combinations thereof. Fifty enamel samples were randomly assigned to five groups (n=10): NaF, HA-NaF-X, L, L + NaF, and L + HA-NaF-X. The chemical composition of human enamel was evaluated before (BT) and after (AT) treatment using energy-dispersive X-ray spectroscopy (EDS) and expressed in atomic percentages (at%). For combined treatment groups, the products were applied after laser irradiation. The statistical analyses included a paired t-test and ANOVA (p≤0.05). After treatment, a significant increase in F at% was observed in the NaF group (2.71 ± 1.41). The irradiated groups showed significant increases in Ca and P at% and the Ca/P ratio. The highest values occurred for L + NaF (30.44 ± 4.28 Ca at%, 11.97 ± 1.45 P at%, and 2.55 ± 0.22 Ca/P ratio). Er:YAG laser irradiation alone or in combined protocols increased the Ca and P content of dental enamel, in vitro

Poly(3-hydroxybutyrate) graft copolymer dense membranes for human mesenchymal stem cell growth

Background: The use of novel materials as an artificial extracellular matrix for stem cell growth is a current strategy of increasing interest for regenerative medicine. Here, we prepare thermal-remolded membrane scaffolds from poly(3-hydroxybutyrate) grafted with 2-amino-ethyl methacrylate hydrochloride. However, it is unclear whether these membranes are useful for tissue engineering. Results: The mechanical properties, tribology, and morphology of the dense membranes were assessed. The results show that tensile strain at break and roughness of the compressed membrane decrease with increasing graft degree. Moreover, graft copolymer membranes showed lower resistance to scratching, greater degree of swelling and higher brittleness than un-grafted P(3HB) films. Thus, it effectively supports the growth of dermal fibroblast, as demonstrated by epifluorescence microscopy. Conclusions: It is concluded that the developed membrane can be properly used in is the restoration of skin tissue.How to cite: González-Torres M, Sánchez-Sánchez R, Solís-Rosales SG, et al. Poly(3-hydroxybutyrate) graft copolymer dense membranes for human mesenchymal stem cell growth. Electron J Biotechnol 2018, 34; https://doi.org/10.1016/j.ejbt.2018.05.007. Keywords: Artificial extracellular matrix, Dense membranes, Membrane scaffolds, Mesenchymal, Methacrylate, Regenerative medicine, Scaffolds, Stem cell growth, Stem cell growth, Thermal properties, Thermal-remolde