Additives Incorporated in Cellulose Acetate Membranes to Improve Its Performance as a Barrier in Periodontal Treatment

In this study, we prepared cellulose acetate membranes, by means of casting mold, incorporated with two additives, sodium carboxymethyl lignin and calcium glycerophosphate, in order to improve properties for periodontal applications. The membranes were characterized from the morphological, structural, thermal and mechanical point of view, as well as by physiological pH tests. The results showed that membranes with additives improve the physical-chemical and mechanical properties, especially when the two additives are present in the same membrane, which can be attributed to the important synergy between them. The most significant effects occur in increasing the thickness and decreasing the density, which reflects in the porosity of the membranes, although the added amounts do not exceed 1.4%. A 1% increase in lignin concentration does not change the thickness and density of the membrane, but that amount of lignin plus 0.4% calcium glycerophosphate increases the thickness of the membrane by 42% and decreases the density by about 6%. Although there is a decrease in mechanical properties, as observed in Young's modulus and crystallinity, the significant and intermittent increase in sample weight loss with both additives in physiological solution indicates that, in the long run, it can be used as a degradable barrier.

Influence of Glycerophosphate Salt Solubility on the Gelation Mechanism of Colloidal Chitosan Systems

Recently, thermosensitive chitosan systems have attracted the interest of many researchers due to their growing application potential. Nevertheless, the mechanism of the sol-gel phase transition is still being discussed, and the glycerophosphate salt role is ambiguous. The aim of the work is to analyze the possibility of the exclusive use of a non-sodium glycerophosphate salt and to determine its impact on the gelation conditions determined by rheological and turbidimetric measurements as well as the stability of the systems by measuring changes in the Zeta potential value. It was found that ensuring the same proportions of glycerophosphate ions differing in cation to amino groups present in chitosan chains, leads to obtaining systems significantly different in viscoelastic properties and phase transition conditions. It was clearly shown that the systems with the calcium glycerophosphate, the insoluble form of which may constitute additional aggregation nuclei, undergo the gelation the fastest. The use of magnesium glycerophosphate salt delays the gelation due to the heat-induced dissolution of the salt. Thus, it was unequivocally demonstrated that the formulation of the gelation mechanism of thermosensitive chitosan systems based solely on the concentration of glycerophosphate without discussing its type is incorrect.

Preparation and Biological Activity of Strontium Modified Titanium Oxide Surface

Titanium (Ti) is a bone tissue replacement material with excellent mechanical properties. However, Ti has poor biological activity and lacks osseointegrative properties and may trigger inflammation and cause implantation failure. To address these issues, Ti surface modification has become a widely used method. In this study, using microarc oxidation (MAO) technology, a strontium-doped MAO coating was prepared on Ti surfaces in an electrolyte solution comprising calcium acetate, calcium glycerophosphate and strontium acetate. Scanning electron microscopy (SEM) and energy spectrum analysis (EDS) were used to analyze the tissue structure and elemental composition of the coating. The surface phase composition of the coating was analyzed by X-ray diffraction (XRD). We observed the proliferation of cells on the coating surface through in vitro cell experiments. The results showed the surface of the strontium-doped MAO coating is porous, and strontium is evenly distributed on the surface. The coating can promote the adhesion, proliferation and differentiation of osteoblasts and has good biological activity and thus, could potentially be applied to the surface of implants in clinical application.

Evaluation of Rremineralization Capacity of Non-fluoride Home Products

The aims of the study were to characterize enamel, dentine and cementum surface aspect after using non-fluoride remineralization toothpastes containing calcium carbonate and calcium glycerophosphate by SEM evaluation, to determine chemical composition of enamel, dentin and cement after remineralization products application by EDX assessment, and to compare the remineralization capacity of the tested products. Ten extracted teeth having no dental caries, erosive or wear lesions were selected for the study. The teeth were split bucco-lingually and mesio-distally in four pieces. A free window of enamel, dentine, and cementum (4X4 mm) in the cervical area of the slices was preserved. In control group the slices were subjected to a artificial caries lesion formation. In study groups EcoBio� (President Company), Bio-natural (Dentissimo, Swiss Biodent), and Arthrodont Cassic (Pierre Fabre Oral Care) toothpastes were applied two times a day, for 3 minutes during caries lesion formation. The surface topography has been analyzed using a scanning electron microscope and the quantitative and qualitative chemical composition has been evaluated using an EDX detector. Interprismatic and intraprismatic mineral loss is clearly visible at higher magnification in enamel samples in control group. Some areas of demineralization are still present, and also small areas of extern deposits are visible on enamel, dentine and cementum samples in the groups were tested products were applied. All the tested toothpastes increased calcium and phosphorous ion concentrations in enamel, dentine and cementum. The highest remineralization effect was recorded in enamel by Dentissiomo, followed by Arthrodent and EcoBio toothpastes. In dentine and cementum the highest remineralization effect was registered by Arthrodent, followed by Dentissiomo and EcoBio toothpastes.