Oxygen plasma immersion ion implantation treatment enhances the human bone marrow mesenchymal stem cells responses to titanium surface for dental implant application.

OBJECTIVES: The present investigation utilized a novel oxygen plasma immersion ion implantation (O-PIII) treatment to create a dense and thin oxide layer on a titanium (Ti) surface for dental implant application. MATERIALS AND METHODS: This study evaluated the behavior of human bone marrow mesenchymal stem cells (hMSCs) on O-PIII-treated Ti. The O-PIII treatments were performed using different oxygen ion doses (T(L): 1 × 10(16); T(M): 4 × 10(16); T(H): 1 × 10(17) ions/cm(2)). RESULTS: Analysis using an X-ray photoelectron spectrometer (XPS) and high resolution X-ray diffractometer (HR-XRD) indicated that the O-PIII-treated specimen T(M) had the highest proportion of rutile phase TiO2 component. The O-PIII-treated specimen T(M) had the greatest protein adsorption capability of the test Ti surfaces using XPS analysis and bicinchoninic acid (BCA) protein assay. Immunofluorescent staining revealed that hMSCs had the best cell adhesion on the O-PIII-treated specimen T(M), whereas green fluorescent protein (GFP)-labeled hMSCs experienced the fastest cell migration based on a wound healing assay. Other assays, including MTT assay, Alizarin red S staining and Western blot analysis, demonstrated that the adhered hMSCs exhibited the greatest cell proliferation, mineralization, and differentiation capabilities on the TM specimen. CONCLUSIONS: Oxidated Ti (primarily rutile TiO2 ) was produced using a facile and rapid O-PIII treatment procedure, which enhances the biocompatibility of the Ti surface with potential implications for further dental implant application.

Effect of oxygen plasma immersion ion implantation treatment on corrosion resistance and cell adhesion of titanium surface.

OBJECTIVE: The study was to investigate the corrosion resistance and cell adhesion of titanium (Ti) surface for dental implant application by oxygen plasma immersion ion implantation (O-PIII) treatments. MATERIALS AND METHODS: Commercially pure Ti discs (grade 2) were used as the substrate. O-PIII surface treatments, with different oxygen doses (1 × 10(16) and 4 × 10(16) ions/cm(2)), were performed in a high-vacuum chamber with a radio frequency plasma source. Atomic force microscope, X-ray photoelectron spectrometer and nanoindenter were used to analyze surface topography, chemical composition (three samples per group) and mechanical property (twenty-five samples per group) of Ti specimens, respectively. Corrosion resistance of Ti specimens (five samples per group) was evaluated by potentiodynamic polarization curve measurement in simulated blood plasma solution. The adhesion and spreading of human bone marrow mesenchymal stem cells (hMSCs) on Ti surfaces were studied. RESULTS: The results showed that O-PIII treatment had no significant influence on the surface topography of Ti specimens. The thickness of oxide layer (mainly as TiO(2)) on the O-PIII-treated Ti specimens increased with an increase in oxygen dose implanted. The O-PIII-treated Ti specimens possessed higher surface hardness and Young's modulus than the untreated Ti specimen. Potentiodynamic polarization tests revealed that the O-PIII-treated Ti surfaces had lower corrosion rate (I(corr)) and passive current (I(pass)) than the untreated Ti surface. The adhesion and spreading of hMSCs on Ti surfaces were improved by O-PIII treatment. CONCLUSIONS: O-PIII treatment could enhance the corrosion resistance and cell adhesion of Ti surface for dental implant application due to the increase in surface thickness of Ti-oxides (mainly as TiO(2)) on Ti.

ZrO(2)/hydroxyapatite coating on titanium by electrolytic deposition.

In this study, hydroxyapatite (HA) was coated on a titanium (Ti) substrate over a ZrO(2) layer by the electrolytic deposition method, this double layer coating was then compared with a single layer coating of HA. The HA layer was used to increase the bioactivity and osteoconductivity of the Ti substrate, and the ZrO(2) layer was intended to improve the bonding strength between the HA layer and Ti substrate, and to prevent the corrosion of the Ti substrate. The electrolytic deposition formed an HA layer with a thicknesses of approximately 20 mum, which adhered tightly to the Ti substrate. The bonding strength of the HA/ZrO(2) double layer coating on Ti was markedly improved when compared to that of the HA single coating on Ti. The improvement in bonding strength with the use of a ZrO(2) base layer was attributed to the resulting increase in chemical affinity of the ZrO(2) to the HA layer and to the Ti substrate. The osteoblast-like cells cultured on the HA/ZrO(2) coating surface, proliferated in a similar manner to those on the HA single coating and on the pure Ti surfaces. At the same time, the corrosion resistance of Ti was improved by the presence of the ZrO(2) coating, as shown by a potentiodynamic polarization test.

A comparison of Q-switched alexandrite laser and intense pulsed light for the treatment of freckles and lentigines in Asian persons: a randomized, physician-blinded, split-face comparative trial.

BACKGROUND: Q-switched (QS) pigmented lasers and intense pulsed light (IPL) successfully treat pigment disorders. OBJECTIVE: We sought to compare efficacy and side effects of QS alexandrite laser (QSAL) and IPL for freckle and lentigo treatment in Asians. METHODS: In all, 15 patients with freckles and 17 patients with lentigines were treated randomly with one session QSAL in one cheek and two sessions IPL in the other cheek at 4-week intervals. Efficacy was determined using a new pigmentation area and severity index score. RESULTS: All patients experienced improvement (P < .0001). Postinflammatory hyperpigmentation developed in one patient with freckles and 8 patients with lentigines after QSAL. No postinflammatory hyperpigmentation occurred after IPL. Freckles achieved greater improvement after QSAL than IPL (P = .04). In lentigines, the results after IPL were better than QSAL among those with postinflammatory hyperpigmentation after QSAL. LIMITATIONS: Limitations include a small case number and short follow-up period. CONCLUSION: QSAL was superior to IPL for freckle treatment. IPL should be used for lentigines in Asian persons.