Abstract: Improved cement technique by interposing less than two layers of hydroxyapatite
(HA) granules between bone and bone cement at the cementing (Interface Bioactive Bone
Cement : IBBC) have been performed in total knee arthroplasty (TKA). 140 knees (120
patients) could be followed up clinically and radiologically. As a control, clinical results of
TKA with conventional cementing (Non-IBBC) were used. In IBBC cases, the appearance
rate of the radiolucent lines on the tibial components and the periprosthetic osteolysis of the
tibial components were significantly low. In IBBC, bone cement bound to HA mechanically
immediately after surgery and HA granules bound to the bone physicochemically after bone
ingrowth into the spaces around the HA granules. Thus, we believe that IBBC is a method
combining the advantage of cementless HA coating and bone cement.
Abstract: In this paper, the hydration product of calcium phosphate cement with bioactive glass
containing Si was used to investigate the effect of chemical composition on its bioactivity. The
variation of concentrations of Ca2+, P and Si in TE solution complemented with electrolytes typical
for plasma (TEE) and the formation of amorphous calcium phosphate layer on the surface of the
materials were investigated by immersing the designed materials in TEE solution in vitro. The results
showed that the composition of the bioactive composite CPC greatly affected its behavior in the
solution and the formation of bioactive apatite. After immersed in TEE solution, the Ca ions were
uptaken for all the samples, showing the decreases of Ca concentration during the entire duration, but
the concentration of P ions increased sharply at the initial stage, and then decreased due to the
formation of amorphous calcium phosphate layer on the surface of the materials. FTIR revealed that
the layer was poorly crystallized Ca-deficient carbonate apatite. The thickness of the layer was more
than 12 um, which layer was composed of rod-like apatite with directional arrangement. All the data
obtained would be useful for the design and optimization of the orthopedic degradable implant
Abstract: A composite bone cement designated G2B1 that contains β tricalcium phosphate particles
was developed as a bone substitute for percutaneous transpedicular vertebroplasty. In this study, both
G2B1 and commercial PMMA bone cement (CMW1) were implanted into proximal tibiae of rabbits
with a metal frame fixed on it, and their bone-bonding strengths were evaluated at 4, 8, 12 and 16
weeks after implantation using a detaching test. Some of the specimens were evaluated histologically
using Giemsa surface staining and scanning electron microscopy (SEM). It was found that the
bone-bonding strength of G2B1 was significantly higher than that of CMW1 at each time point, and
significantly increased from 4 weeks to 8 and 12 weeks, while it decreased significantly from 12
weeks to 16 weeks. Giemsa surface staining and SEM showed that G2B1 contacted bone directly
without intervening soft tissue in the specimens at each time point, while there was always a soft
tissue layer between CMW1 and bone. The results indicate that G2B1 has excellent bioactivity.
Abstract: In this study, the antibacterial effects of glass ionomer cement containing silver-zeolite
were evaluated. New antibacterial glass ionomer cements with silver-zeolite were prepared as
follows. Silver-zeolite (1, 3, and 5 wt%) was incorporated into the glass ionomer cement powder
and then mixed with the polyacidic liquid at the ratio recommended by the manufacturer. Agar
diffusion test was used to evaluation of antibacterial effect. Setting time, film thickness and
compressive strength were also determined. Paired samples t-tests and ANOVA were used, and
P<0.05 was considered significant. Film thickness and setting time were increased dependent on the
amount of silver-zeolite. Glass ionomer cement with 1 wt% of silver-zeolite seemed to increase the
compressive strength. However, increasing ratio of compressive strength was diminished beyond 3
wt%. Glass ionomer cements containing silver-zeolite have been successfully demonstrated to have
antimicrobial effects on S. mutants in vitro. These results indicate that glass ionomer cement
containing silver-zeolite have the potential to enhance antibacterial of dental cement in oral cavity.
Abstract: Low crystalline apatite (LCA) and calcium phosphate cements (CPC) based on amorphous
calcium phosphate and dicalcium phosphate dihydrate (1 to 1 ratio) were combined with
bioresorbable PLGA copolymer (0 to 20 wt.%) for preparation of solid-formed devices.
A pilot manufacturing based on powder processing techniques using isostatic pressure
(44,000 psig) was conducted. Processing parameters such as isostatic pressure, temperature,
times and device dimension were varied to achieve appropriate mechanical properties
comparable to that of allograft bone dowel used as a gold standard in clinical application.
The solid-form devices were characterized for physico-chemical and mechanical
performance, as well as subjected to an in-vitro wet environment incubation at body
temperature (37°C). Fluid diffusion was investigated to evaluate the fluid absorption (through
microporosity) and the compressive strength of wet devices vs. incubation time (up to 30
days) was also studied. The shear strength and compressive strength of pure LCA dowels was
respectively 26 and 122 MPa, which corresponds to a process densification of about 30%.
The compressive strength was dramatically improved with addition of various amounts of
copolymer. The maximum compressive strength of 180 MPa was obtained for dowels
containing 10 wt.% copolymer. Calcium phosphate composite also increased the shear
strength to about 42 MPa. These mechanical performances were significantly higher than that
of allograft bone dowel (MD-II™), reported about 10 MPa.
A pilot sheep interbody fusion of lumbar spine (L3/L4 and L4/L5) demonstrates
mechanical integrity and intervertebral fusion at 6 months.
LCA was found to be the most suitable CaP material because of its biocompatibility,
chemical composition, nano-structure and high specific surface area that exhibits in-vivo
biointegrity and cell mediated process.
Abstract: Crystallized apatite behaved to plaster of Paris was prepared by the chemical method.
Apatite powder was mixed with chitosan. In this study, it was also studied the effect of HA seed and
sodium hydrogen phosphate as an additive on their mechanical strength, compared with the normal
calcium phosphate cements. Setting time of paste cements was determined using Gillmore method.
Phases of cement obtained from a crushed cylinder were analyzed using XRD analysis. From the
results, chitosan was effective both in increasing mechanical properties and accelerating hardening of
the normal bone cements. Nevertheless, the compressive strength of chitosan-crystallized apatite
composites was not significantly improved as compared to the controlled one. In addition, it was
found that the mechanical strength of the cements decreased when increasing the concentration of HA
seed and an additive.
Abstract: In this study modified starch were used as anti-washout promoters of injectable calcium
phosphate cement (CPC) and the effects of the modified starch on the injectability, anti-washout
performance, setting time, compressive strength, phase evolution and microstructure of this cement
were investigated. The injectability of the cement was improved by adding the modified starch
(0.5-2.0%). After mixing with modified starch (0.5-2.0%), the cement showed better anti-washout
performance than that without modified starch after immersed and shaken in SBF. Especially, when
the content of the modified starch was 1.0%, the remaining percentage of the cement was reached to
92.6%, but only 5.9% of the CPC paste remained and set for the sample without modified starch after
shaken for 2 hrs. The compressive strength of cements significantly increased from 44 MPa to 54
MPa when 0.5% of modified starch was added. And a slight increase on the mechanical strength can
be observed for other concentrations. Powder X-ray diffraction analysis revealed no significant
difference for the conversion of the cement to hydroxyapatite for any concentrations of modified
starches. The influence of the modified starch on the microstructure of the set cement was also
studied. The results showed the modified starch would reduce the acicular crystal size of
hydroxyapatite accompanied with little flaky crystals generation and made a compact structure. It is
concluded that modified starch, a suitable anti-washout promoter, improved the performance of CPC.
Abstract: An injectable bone substitute (IBS) made of a suspension of calcium phosphate ceramic
was used to filled dental root canal after removing of canal pulp. Compared with current filling
materials, which are toxic to periapical tissues, calcium phosphate materials, due to their
biocompatibility and bioactive properties, may be viewed as possible alternatives.
The aim of this study was first to determine if an injectable bone substitute could be used to obtain
further healing of apical tissue by the neoformation of a mineralized barrier. In the next step, the
paper will focus on rheological measurements as a tool for physical characterisation and on the
improvement of the injection technique. Rheology concerns the flow and deformation of the
suspension and, in particular, its behaviour in the transient area between solids and fluids. The
results showed that injection is possible with a good level of BCP granules at the end of the root
dental canal with extracted tooth. Other experiments with other animal models closer to a Human
model have to be performed before human trials.
Abstract: The purpose of this study was to evaluate histologically the effect of LiF-maleic acid
added calcium aluminate (LM-CA) bone cement and calcium aluminate-polymethylmethacrylate
(CA-PMMA) composite bone cement on bone regeneration in rat calvarial defect. After calvarial
defects in 8 mm in diameter were created, three groups of 10 animals, a total of 30, each either
received LM-CA bone cement, CA-PMMA composite bone cement or a sham-surgery control.
Histologic analysis was done at 2 weeks and 8 weeks of healing periods. We concluded that LM-CA
bone cement can be used as a bioactive bone graft material due to ability of bonding to the existing
bone and CA-PMMA can be used as a graft material for augmentation of bone-volume due to
Abstract: Control of protein release without the initial burst from zinc containing hydroxyapatite
porous microparticles (Zn-HAp) was investigated with a novel formulation method. The formulation
method was a coat of polyL(L-lactide; PLA) on the microparticle with nano-thickness, which
obviously suppressed the initial burst of protein release compared with the microparticles without the
formulation, the coat of PLA. The HAp/PLA microparticle with 1-20μm of the size distribution was
available for the drug delivery carrier of proteins without the degradation.