Abstract: Fine nanoapatite relics were deposited on glass substrates by electrohydrodynamic
atomisation, using nanohydroxyapatite (nHA), nano-carbonated hydroxyapatite (nCHA) and nanosilicon-
substituted hydroxyapatite (nSiHA) suspensions. These electrosprayed nanoapatites were
evaluated in-vitro using simulated body fluid (SBF) and human osteoblast (HOB) cells. The SBF
study revealed that newly-formed apatite layers were observed on the surface of the relics.
Furthermore, enhanced HOB cell growth was observed on each of the nanoapatites at all time
points. Hence, this work demonstrated that electrosprayed nanoapatites offer considerable potential
Abstract: The aim of this study was to evaluate potential effects of DNA-coatings on calcium
phosphate (CaP) nucleation from simulated body fluids (SBF) and subsequently the effects of
DNA-coatings and SBF-immersed DNA coatings on the behavior of osteoblast-like cells. DNAcoatings
demonstrated to enhance the nucleation and deposition of CaP from SBF compared to
titanium controls. The behavior of osteoblast-like cells was affected on SBF-immersed DNAcoatings,
showing an increased deposition of the extracellular matrix protein osteocalcin compared
to titanium controls. These results indicate bone-bonding capacity of DNA-coatings, which needs to
be confirmed using future animal experiments.
Abstract: Titanium is well known as an implant material having excellent biocompatibility and
mechanical properties for use in bone substitute. In the present study, to enhance the
biocompatibility of titanium, its surface was modified by hydrothermal treatment using dilute
alkaline solution. After hydrothermal treatment, anatase predominantly formed on a titanium
surface. The anatase phase showed high crystallinity and c-axis orientation. The anatase layers
with leaf-like and pyramid-like forms were observed on titanium autoclaved at 120 °C and 240 °C,
respectively. The anatase formation and its morphology were significantly related to the
autoclaving temperature. To estimate the cellular compatibility of the autoclaved titanium, mouse
osteoblast-like cells (MC3T3-E1 cells) were cultured on the autoclaved titanium surface. After 7-
days culturing, the number of the cells harvested from the autoclaved titanium was higher than that
from untreated titanium. The surface modification of titanium by hydrothermal treatment involved
the proliferation of the cells on its surface.
Abstract: Titanium dental implants presenting different blasted surfaces and an OCP coated
surfaces have been implanted in the femoral epiphysis of rabbits. A comparable osseointegration has
been observed for the titanium implants blasted either with alumina or biphasic calcium phosphates
particles whatever the delay of implantation (2 or 8 weeks). A higher bone to implant contact has
been observed for the SLA and OCP coated implants as compared to the grit-blasted groups.
Abstract: The aim of this study was to deposit an adherent apatite coating on titanium substrate
using a two-step chemical deposition method. First, titanium substrates were immersed in an acidic
solution containing calcium and phosphate ions, resulting in the deposition of a monetite (CaHPO4)
coating. Second, the monetite crystals were converted to apatite by hydrolysis in NaOH solution.
Composition and morphology of the initial and final coatings were identified using X-ray diffraction
(XRD), Scanning Electron Microscopy, and Energy Dispersive Spectroscopy (EDS). The final
coating was porous and the apatite crystals were agglomerated and followed the outline of the large
monetite crystals. The average tensile bond of the coating was 5.2 MPa and cohesion failures were
observed more frequently than adhesion failures. The coating adhesion measured using scratch test
was 13.1N. In conclusion, this study showed the potential of a two-step chemical deposition method
for depositing an adherent coating of apatite at low temperatures.
Abstract: Apatite formation on the surface of materials in body environment is an essential condition
to show osteoconduction after implantation in bony defects. This study reports the novel technique for
providing the apatite-forming ability to titanium metals by only controlling the spatial gap and
thermal oxidation. Two pieces of titanium thermally oxidized at 400 °C were set together like V-letter
with varied mouth opening. They showed the formation of apatite on both facing surface after
exposure to a simulated body fluid (SBF) proposed by Kokubo and his colleagues, when the gap was
less than approximately 600 μm. Moreover, specimens with micro-grooves of 500 μm in depth and
200-1000 μm in width was able to form apatite in SBF with in 7 days, after they were thermally
oxidized at 400 oC. These results indicated that the titanium metals were provided with
apatite-forming ability, i.e. osteoconduction, due to controlled gap with thermally oxidized surface.
Hence, we conclude that bioactive titanium substrate showing osteoconduction can be produced by
designed machining followed by thermal oxidation at an appropriate temperature.
Abstract: An apatite layer was successfully formed on titanium substrates by electrochemical
deposition under a pulse current in a metastable calcium phosphate solution, which had 1.5 times the
ion concentrations of a normal simulated body fluid, but did not contain MgCl2·6H2O, at 40 °C for 30,
60, 90 and 120 minutes at the average current density of 10 mA/cm2. The thickness of the apatite layer
was increased with increasing deposition time. The pulse-current deposition produced the thicker
apatite layer than the direct-current deposition, and gave some effects on the surface morphology of
the apatite. The pre-treatment using acid solution gave a better adhesive between apatite and substrate.
It is expected that the present electrochemical deposition under a pulse current will be useful to
rapidly coat apatite on metallic materials.
Abstract: When producing implant materials, achievement of optimal bioactivity and
biocompatibility are essential. Nanocoatings can provide an efficient cost effective way to alter the
interactions of the implant material with its destined “host” environment. Nanocoatings of sol-gel
derived carbonated hydroxyapatite (HAp) and zirconia were produced in this study. The surfaces
were characterised by Fourier transform infrared spectroscopy (FTIR) and light microscopy. Cell
adhesion, proliferation and viability, as well as expression of alkaline phosphatase (ALP is an
indicator of bone formation) were assessed as indicators of biocompatibility. Our results have
shown that sol-gel derived nano crystalline HAp acts as an ideal surface for implant coatings.