Bone repair and regeneration

At the beginning of their research work, the Doctors Camprasse focussed focused on the properties of mother-of-pearl as a bone substitute, with the aim of proposing an alternative to titanium dental implants. They then extended their research work to orthopaedic bone repair and regeneration. Look at their extensive work, backed by publications in scientific journals.

Field of application: dentistry

To test out and demonstrate the proprieties of mother-of-pearl in the dental field, the Doctors Camprasse began by carrying out their first pre-clinical cases (on dogs). First, they did so privately, then at the French National Veterinary School’s Biomedical Research Centre [Centre de Recherche Biomédicale de l’Ecole Nationale Vétérinaire] in Maisons-Alfort.

Biocompatibility of mother-of-pearl

 Publication in scientific journal Médecine et Thérapeutique

Substitution, in animals and human subjects, of the dental nerve with the skeletons of aquatic invertebrates [Substitution de la racine dentaire par des squelettes d’invertébrés aquatiques chez l’animal et l’homme]

The aim of this clinical study was to demonstrate perfect biocompatibility between the maxillary bone and the naturally-occurring CaCO3 in skeletons of aquatic invertebrates (coral and Pinctada maxima). The conclusion is as follows: it now appears possible to use artificial roots made of aragonite in oral implantology on a routine basis. The Doctors Camprasse noted rapid osteointegration, which appears to be generated by osteoinduction due to chemotaxis of the material on the bone cell.

Tooth root

Osteointegration and osteoconduction in mother-of-pearl

1989 Publication in scientific journal Medicine and Therapeutics

Seamless melding (osteoassimilation) of the human maxillary bone with a compact dental implant made of natural calcite from marine invertebrates [Soudure sans transition (Ostéoassimilation) entre l’os maxillaire humain et un implant dentaire compact en calcite naturel d’invertébrés marins]

The aim of this clinical study was to demonstrate osteointegration between the human maxillary bone and a compact dental implant made of natural calcite from marine invertebrates (coral and Pinctada maxima).

The conclusion is as follows: The Doctors Camprasse successfully demonstrated perfect osteointegration between the human maxillary bone and the dental implant made of mother-of-pearl (natural CaCO3). They even observed the formation of new autologous bone, and resorption of the implant. Unlike implants made of titanium (potentially allergenic particles), the implant made of natural mother-of-pearl is totally bioresorbable.

Radiography of a Bioracine made of mother-of-pearl (Pinctada) (B), surrounded by newly-formed bone (->)

Mechanical properties of mother-of-pearl

1990 Publication in scientific journal Clinical Materials

Artificial dental root made of natural calcium carbonate (Bioracine)

The aim of this clinical study was to highlight the exceptional mechanical properties of mother-of-pearl (hardness, strength, elasticity).

The conclusion reached by the Doctors Camprasse is as follows: the artificial dental root made from mother-of-pearl, taken from the internal shell of the Pinctada maxima, is very close to bone tissue in terms of its physical and chemical composition, and presents remarkable hardness, strength, and elasticity.

A histological study of the interface between the implant and the human maxillary bone also demonstrated an extraordinary union cellular union between these two tissue types. Mother-of-pearl is an exceptional tooth substitute, with biological properties matching those of natural bone.

Pinctada Maxima

Regeneration of the maxillary bone (Odontostomatology)

1991 Publication scientifique dans Implantodonné

Un biomatériau de régénération osseuse nouveau – Etude clinique

Après avoir démontré in vivo que la nacre était un biomatériau non toxique, bioactif et ostéogène, les Docteurs Camprasse ont travaillé sur différentes pathologies odontostomatologiques, par le biais d’études cliniques à l’Hôpital Lariboisière : comblement des défauts osseux, élévation des crêtes maxillaires ou mandibulaires, remodelage des pertes de substance, augmentation de l’épaisseur vestibulo-palatine ou vestibulo-linguale en implantologie , et extractions délabrantes.

Les conclusions sont les suivantes : avec un recul de 4 ans, les Docteurs Camprasse sont en mesure d’avancer que Bionacre® (sous forme de poudre utilisée en coagulum) est un biomatériau de régénération osseuse extrêmement performant qui ouvre en chirurgie osseuse des champs multiples.

Powdered mother-of-pearl used as a coagulum

Field of application: orthopaedics

Following their major discoveries concerning the properties of mother-of-pearl in dental implantology, in the early 1990s the Doctors Camprasse broadened their clinical research work to encompass fundamental clinical research, to gain an understanding of the behaviour of mother-of-pearl on bone cells generally.

Osteoinduction in mother-of-pearl

1992 Publication in scientific journal Tissue and Cell

Demonstration of the capacity of nacre to induce bone formation by human osteoblasts maintained in vitro

The aim of this study was to test out the hypothesis according to which mother-of-pearl may stimulate biomineralisation in human osteoblast maintained in vitro.

The conclusion is as follows: The Doctors Camprasse successfully demonstrated that when human osteoblasts were cultivated in the presence of mother-of-pearl, a complete bone formation sequence was reproduced. The Doctors were the first to demonstrate that mother-of-pearl contains molecular factors that induce osteoblastic differentiation, and that this osteoblastic differentiation enables the triggering of the bone’s biomineralisation mechanism. At the same time, they also demonstrated that mother-of-pearl is not cytotoxic to bone cells.

Bone cell osteoblast

Osteogenic activity of mother-of-pearl (orthopaedics)

1992 Publication in scientific journal Calcified Tissue International

Nacre initiates biomineralization by human osteoblasts maintained in vitro

The aim of this study was to test out the hypothesis according to which there may be simultaneous presence of bone and mother-of-pearl on human osteoblasts. Previously, the Doctors Camprasse had demonstrated that osteoblasts were able to differentiate themselves and thus trigger the bone’s biomineralisation mechanism.

The conclusion is as follows: The Doctors Camprasse successfully demonstrated that mother-of-pearl does have a powerful osteogenic effect on human osteoblasts when they are placed near the bone. In other words, mother-of-pearl has this spectacular ability to induce the formation of new, fresh bone.

Bone tissue under the microscope

Interface between bone and mother-of-pearl implant

2014      Publication in scientific journal Journal of Raman Spectroscopy

The interface between nacre and bone after implantation in the sheep: a nanotomographic and Raman study

The aim of this study was to analyse the interface between bone and mother-of-pearl, in order to better ascertain biocompatibility with bone. The study was carried out on the bones of five sheep.

The conclusion is as follows: The Doctors Camprasse successfully confirmed a modification of the bone tissue around the mother-of-pearl implant and the direct affixation of the bone, without a layer of organic matter, sandwiched between the calcium carbonate and the calcium phosphate. In other words, osteointegration of the mother-of-pearl occurs thanks to the formation of new bone.

Nanotomography of an orthopaedic screw

in a sheep bone

In vivo assessment of bio-erosion and of the affixation of mother-of-pearl screws onto the bone

2016         Publication in scientific journal Orthopaedics & Traumatology: Surgery & Research

In vivo erosion of orthopaedic screws prepared from nacre (mother of pearl)

The aim of this study was to analyse the behaviour of mother-of-pearl screws with the hypothesis according to which the screw would be assimilated by the bone without inflammatory effects, and without rejection occurring.

The Doctors Camprasse noted several phenomena:

  • The erosion is gradual
  • The cells do not have ragged edges (no inflammation)
  • The mineralisation rate is augmented in the vicinity of the mother-of-pearl screw

In conclusion, mother-of-pearl screws have the advantage of presenting in vivo resorbability properties thanks to the cells that originated from the macrophages, and to their osteoconductive affixation onto the material, without setting off a local inflammatory reaction.

In vivo study

on a sheep bone

Cell turnover

2019         Publication in scientific journal Journal of Materials Science: Materials in Medicine

Giant cells and osteoclasts present in bone grafted with nacre differ by nuclear cytometry evaluated by texture analysis

The aim of this study was to analyse the interface between the mother-of-pearl implant and the bone.

The Doctors Camprasse observed that there was partial erosion on the surface of the mother-of-pearl screw, a few microns deep. This highlights the melding between the bone and the mother-of-pearl screw and goes some way towards showing the osteointegration of the screw in the bone. In other words, the screw “becomes” the bone.

n : nacre, ob : old bone, nfb : newly-formed bone

Critical clinical study

15-cm femur bone loss

Surgery carried out on a human subject at Hôpital Béclère hospital, by Doctor Philippe Cottin

  1. Gunshot wound (buckshot), with a 15-cm femur bone loss.
  2. After multiple complications and two failed iliac crest autografts, decision to use the bone substitute Bionacre® to remodel the sequester.
  3. Five years on, good consolidation of the femoral core. No septic processes or fistula
  4. 20 years on, consolidation and remodelling of the medullary canal.