Structural modification of titanium surface by octacalcium phosphate via Pulsed Laser Deposition and chemical treatment.

In the present study, the Pulsed Laser Deposition (PLD) technique was applied to coat titanium for orthopaedic and dental implant applications. Calcium carbonate (CC) was used as starting coating material. The deposited CC films were transformed into octacalcium phosphate (OCP) by chemical treatments. The results of X-ray diffraction (XRD), Raman, Fourier Transform Infrared Spectroscopy (FTIR) and scanning electron microscopy (SEM) studies revealed that the final OCP thin films are formed on the titanium surface. Human myofibroblasts from peripheral vessels and the primary bone marrow mesenchymal stromal cells (BMMSs) were cultured on the investigated materials. It was shown that all the investigated samples had no short-term toxic effects on cells. The rate of division of myofibroblast cells growing on the surface and saturated BMMSs concentration for the OCP coating were about two times faster than of cells growing on the CC films.

Glass-ceramic coated Mg-Ca alloys for biomedical implant applications.

Biodegradable metals and alloys are promising candidates for biomedical bone implant applications. However, due to the high rate of their biodegradation in human body environment, they should be coated with less reactive materials, such, for example, as bioactive glasses or glass-ceramics. Fort this scope, RKKP composition glass-ceramic coatings have been deposited on Mg-Ca(1.4wt%) alloy substrates by Pulsed Laser Deposition method, and their properties have been characterized by a number of techniques. The prepared coatings consist of hydroxyapatite and wollastonite phases, having composition close to that of the bulk target material used for depositions. The 100µm thick films are characterized by dense, compact and rough morphology. They are composed of a glassy matrix with various size (from micro- to nano-) granular inclusions. The average surface roughness is about 295±30nm due to the contribution of micrometric aggregates, while the roughness of the fine-texture particulates is approximately 47±4nm. The results of the electrochemical corrosion evaluation tests evidence that the RKKP coating improves the corrosion resistance of the Mg-Ca (1.4wt%) alloy in Simulated Body Fluid.

Silver-Doped Calcium Phosphate Bone Cements with Antibacterial Properties.

Calcium phosphate bone cements (CPCs) with antibacterial properties are demanded for clinical applications. In this study, we demonstrated the use of a relatively simple processing route based on preparation of silver-doped CPCs (CPCs-Ag) through the preparation of solid dispersed active powder phase. Real-time monitoring of structural transformations and kinetics of several CPCs-Ag formulations (Ag = 0 wt %, 0.6 wt % and 1.0 wt %) was performed by the Energy Dispersive X-ray Diffraction technique. The partial conversion of ß-tricalcium phosphate (TCP) phase into the dicalcium phosphate dihydrate (DCPD) took place in all the investigated cement systems. In the pristine cement powders, Ag in its metallic form was found, whereas for CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt % cements, CaAg(PO3)3 was detected and Ag (met.) was no longer present. The CPC-Ag 0 wt % cement exhibited a compressive strength of 6.5 ± 1.0 MPa, whereas for the doped cements (CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt %) the reduced values of the compressive strength 4.0 ± 1.0 and 1.5 ± 1.0 MPa, respectively, were detected. Silver-ion release from CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt % cements, measured by the Atomic Emission Spectroscopy, corresponds to the average values of 25 µg/L and 43 µg/L, respectively, rising a plateau after 15 days. The results of the antibacterial test proved the inhibitory effect towards pathogenic Escherichia coli for both CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt % cements, better performances being observed for the cement with a higher Ag-content.

Clinical study of the effectiveness of two sonic toothbrushes.

The aim of this study was to determine the oral hygiene effects of two sonic toothbrushes, the Water Pik Sonic Speed (W) and Sonicare (S), compared to a manual toothbrush (Elmex Super 39, E). Thirty-six healthy volunteers between 13 and 69 years of age participated in this single-blind, crossover study. They were randomly assigned to three groups, with 12 participants each. Two weeks after a screening examination, a baseline examination was performed for each participant followed by professional tooth cleaning. Three indices were recorded to assess the oral hygiene status: a papillary bleeding index (PBI), a plaque index for smooth surfaces (PI) and a plaque index for approximal surfaces (API). After instructions on how to use the toothbrushes, each group started the experiment with a different type of toothbrush. After two weeks of application, the indices were recorded a second time. This was followed by two weeks of recess, where each participant used the same brand of manual toothbrush, and then before each group switched to the next toothbrush, participants had another baseline examination and professional tooth cleaning. The three types of brushes were used in the following order: S, E, W; recess; E, W, S; recess; W, S, E. The duration of the study was 12 weeks. A single investigator performed all examinations. The Friedman test and Wilcoxon signed rank test were used for statistical analysis. Compared to the manual toothbrush the Sonic Speed and the Sonicare were more effective in removing plaque and preventing gingivitis. The study indicated that the two sonic toothbrushes may be effective alternatives to a commonly used manual toothbrush.