Dental bone substitute materials in dental implantology

The placement of dental implants requires a proper fixation in the jaw bone. Therefore, sufficient bone quantity, an appropriate bone quality at the implantation site and a proper healing of the implant into the jaw all has to be assured. In 30-40 % of all dental implant procedures an augmentation of bone prior to the implantation is necessary.

Depending on the location of the implantation site, a number of different bone augmentation procedures can be applied and it usually takes 5-6 months following the procedure to achieve sufficient bone for the insertion of a dental implant. Sinus lift is commonly applied to augment bone in the upper jaw, especially for people showing age-associated bone recession. Sinus lift procedures usually require 10-20 cc of bone substitute material. In cases where the jaw ridge is too thin to place dental implants, ridge expansion can be applied. This is achieved by mechanically extending the jaw ridge, often using bone substitute material to augment bone at the jaw ridge. Only a few cc of bone substitute material is needed for this procedure. If dental implants need to be placed at former tooth extraction sites, void filling is necessary. Here, the extraction void is filled with bone substitute material to create a plane surface for placing of the dental implant.

In most cases, the implant does not precisely fit the insertion spot in the jaw. Bone substitute material is used to fill the voids surrounding the implant, resulting in additional mechanical support to the implant and an improved integration of the implant into the bone.

The current gold standard for bone substitute material in dental implantology is bone surgically harvested from a second site in the body (autograft). Autografting minimises the risk of tissue rejection. However, there are severe drawbacks such as morbidity at the donor site, a painful harvesting procedure and considerable extra costs connected to the procedure. Frequently, autografting is used in combination with fully synthetic materials (alloplast), e.g. ß-TCP.

Regenerative bone substitute materials

In the past, bone substitute materials only served as filling materials to mechanically strengthen the defect site. With the concept of natural tissue repair, regenerative bone substitute materials are gaining more and more attention. Regenerative bone substitute materials have the following advantages over purely synthetic alternatives:

• Osteoinductivity: the material has the ability to stimulate bone growth.
• Osteoconductivity: the material has the ability to provide a scaffold upon where new bone can form.
• Resorption: the material is completely replaced by natural bone.

These advantages lead not only to faster healing times but also to predictable clinical outcomes. From a material point of view, growth factor activated synthetic materials will become predominant for use as bone substitute materials, because only these offer the same efficacy as autologous bone without the disadvantages.

MD05, Scil Technology’s dental bone substitute material is a synthetic, fully resorbable, compression resistant dental bone augmentation product combining osteoconductive and osteoinductive properties. Clinical Phase II trials of MD05 have been started in patients undergoing sinus lift implants.

MD05 is a biomaterial with two components: a synthetic inorganic carrier ß-Tricalcium phosphate (ß-TCP) and a recombinant growth factor - rhGDF-5, a human protein that acts by promoting the growth of bone. ß-TCP provides a stable structural matrix for bone augmentation and rhGDF-5 promotes bone growth into the area of placement as the matrix is resorbed. In this way, MD05 encourages the growth of bone without the painful harvesting procedure associated with autografting.