Authors: Guy Daculsi, Daniel Chappard, Eric Aguado, G. Legeay, Pierre Layrolle, Pierre Weiss
Abstract: This paper reports on the research into multiphase bone substitutes carried out by laboratories from the ‘Pays de la
Loire’ region in France. This collaborative research was funded by both the French Government and the Regional
Council in the period 2000-2007. Calcium phosphate bioceramics, polymers and combinations have been
developed as bone substitutes for various maxillofacial and orthopaedic applications. These bone substitutes
should support and regenerate bone tissue and resorb after implantation. In the bone tissue engineering area, they
have been combined with autologous bone marrow cells or bioactive factors. The bone substitutes were tested in
various animal models mimicking clinical situations or under pathological conditions (osteoporosis). In order to
complete our research, the multiphase materials were also evaluated in clinical trials.
Authors: Laurent Le Guenhennec, Eric Goyenvalle, Marco A. Lopez-Heredia, Pierre Weiss, Yves Amouriq, Pierre Layrolle
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.
613
Authors: Ahmed Fatimi, Jean Francois Tassin, Monique Aselo V. Axelos, Pierre Weiss
Abstract: Injectable calcium phosphate (CaP) biomaterial is considered as an injectable bone
substitute (IBS). It was developed to minimize invasive surgery in various applications in
orthopedic and dental surgery. The IBS considered of a polymer solution mixed with biphasic
calcium phosphate (BCP) ceramic particles. Two particle sizes of BCP (40-80 and 80-200μm) were
used and the weight ratio was 40%. This study investigated the influence of polymer solution on the
BCP particles stability. Effects of particles size and limiting viscosity of polymer on the
sedimentation were studied. The polymer concentration and particles size can be adapted to provide
the best stability and storage of IBS.
365
Authors: Marco A. Lopez-Heredia, Borhane H. Fellah, Paul Pilet, C. Leroux, M. Dorget, Pierre Weiss, J. Sohier, Pierre Layrolle
Abstract: Porous Titanium Scaffolds were produced by using a rapid prototyping technique. These
scaffolds were either coated or not with a calcium phosphate coating via an eletrodeposition
method. Rat bone marrow mesenchymal stem cells were cultured on the scaffolds at a density of
106 cells/scaffold for a period of 3 days. Cell proliferation was measured by using the Alamar Blue
assay. The scaffolds were observed by SEM and polarized light microscopy. Constructs were then
implanted subcutaneously for 4 weeks in syngenic rats. Cells proliferated well after seeding. After
subcutaneous implantation, histology and SEM revealed the presence of uniform coatings as well as
Ca and P deposits in the non-coated scaffolds suggesting mineralization.
907
Authors: Borhane H. Fellah, Olivier Gauthier, Pierre Weiss, Daniel Chappard, Pierre Layrolle
Abstract: Autologous bone chips are widely used in orthopedic surgery to fill large defects due to
osteoinductive property but are limited in quantity. Several groups have reported the formation of
mineralized bone after implantation of bioceramics in ectopic sites of different animals. However,
osteoinduction by bioceramics has not yet proved to be equivalent to those of autologous bone. In
this study, we compare the bone inducing capability of autologous bone chips and synthetic
biphasic calcium phosphate (BCP) ceramics granules sintered at various temperatures. Both
materials were implanted in muscles and femurs of goats inside hollow containers for 6, 12 and 24
weeks and analyzed by histology. This study showed that bone tissue formed in contact with micro
porous ceramics sintered at low temperature as well as autologous bone chips both in ectopic and
intrafemoral sites of goats.
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Authors: Julia Bosco, Ahmed Fatimi, Sophie Quillard, Jean Michel Bouler, Pierre Weiss
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.
847
Authors: Guy Daculsi, I. Khairoun, Racquel Z. LeGeros, Françoise Moreau, Paul Pilet, Xavier Bourges, Pierre Weiss, Olivier Gauthier
811
Authors: Marco A. Lopez-Heredia, Pierre Weiss, Pierre Layrolle
Abstract: Calcium phosphates coatings were deposited onto titanium discs via en electrodeposition
method. Discs were blasted with calcium phosphate particles and etched in a mixture of sulfuric and
fluoric acids. Temperatures from 25 to 80°C and current densities from 8 to 120 mA/ cm2 were
used. Deposition times tested were between 10 and 120 min. The electrolyte consisted of a super
saturated solution stirred at 250 rpm. The amount of magnesium (Mg2+) and carbonate (HCO3-)
ions was varied from 0 to 1 mM. Coatings increased in thickness by increasing deposition time. The
different amounts of Mg2+ and HCO3- affected the homogeneity and morphology of the coatings.
Main factors affecting the deposition were temperature of electrolyte and current density.
549
Authors: Julia Bosco, Bénedicte Enkel, Valerie Armengol, Guy Daculsi, Alain Jean, Pierre Weiss
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. The aim of this study was to verify the ability of calcium phosphate ceramic suspension to fill the apical zone of teeth ex vivo (n=40) and in vivo in a sheep model (n=8). 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. In vivo, the presence of blood pressure due to the pulpectomy is a negative parameter to allow a good filling. The scanning electron microscopy revealed mineral formation at the apex level
with mineral tissue conduction between the BCP granules but only one tooth showed a good apical filling with a good sealing. The sealing of the apex seems to depend of the amount of BCP granules. Other experiments with other animal models closer to a Human model have to be performed before human trials.
1157
Authors: Pierre Weiss, Léon Philippe Clergeau, Bénédicte Enckel, Yves Amouriq, Bernard Giumelli, Alain Jean, Guy Daculsi
Abstract: For the first time, an injectable bone substitute (IBS) made of a suspension of Calcium phosphate ceramic was used in a clinical trial in human after extraction of non conservable tooth (36 or 46). 11 patients did agree for implantation of their sockets with the biomaterial. It was an explorative study and the results showed no pain due to the biomaterial implantation, no infection, no inflammation and perfect biocompatibility. The safety and the bioactivity of this concept of biomaterial were confirmed in human implantation after several animals’ pre-clinical studies.
1053