Bone Augmentation using Bone Chips (Bone Chips)

One possible procedure for bone augmentation prior to implant placement (bone augmentation prior to the placement of artificial tooth roots) is the insertion of previously biotechnologically produced autologous bone, the so-called bone chips.Tooth gaps that occur due to premature tooth loss can be closed today in many cases by implant placement (placement of artificial tooth roots). If the jawbone does not provide sufficient volume to accommodate an implant, various surgical procedures are available to obtain bone substance. The gold standard against which other procedures must be measured is the harvesting and preparation of autogenous (body’s own) bone. Since the necessary quantity of 1 to 2 cm³ is usually not available intraorally (in the mouth), the bone must be harvested from the iliac crest. One procedure that aims to avoid this time-consuming operation to remove the patient’s own bone is bone augmentation using bone chips. The biotechnological procedure for their production is called tissue engineering (cell culture technique).Grafts produced by tissue engineering must meet the requirement of providing a three-dimensional carrier scaffold for autologous, osseoinductive (the body’s own cells that trigger bone formation) cells that is well permeable to the nutrient medium during the tissue engineering phase and allows rapid vascularization (sprouting of new blood vessels) after insertion into the bone defect.Advantages of the procedure.

  • Unlike the transplantation (transfer) of autologous (body’s own) bone cancellous bone (spongy fine bone bellows inside the bones), which is taken, for example, the iliac crest, tissue engineering avoids such complex surgical procedures, consequently associated defects, pain and swelling in the removal region.
  • Since the comparatively small removal site for the periosteum is located intraorally (in the mouth), no external scars remain.
  • Since the biotechnologically produced tissue is grown from the body’s own cells, which are recognized by the body as such, no rejection reactions take place.

Disadvantages of the procedureThe advantages are offset primarily by the greater time required for tissue engineering.

Indications (areas of application)

  • For jaw bone augmentation

Contraindications

  • General medical restrictions that prohibit a surgical procedure.

The procedure

I. Harvesting

To produce bone chips, a piece of periosteum (periosteum) measuring approximately 1 cm² must first be removed from the patient in a minor surgical procedure under local anesthesia (local anesthetic). The molar region (the area of the large posterior molars) of the mandible is a suitable site for removal. Sutures are placed to close the wound and are removed after 8 to 10 days. At the same time as the periosteum is obtained, about 150 ml of blood is taken, the serum of which is obtained in the laboratory by centrifugation. The serum is needed as a nutrient medium for culturing the bone cells. The initial substances for the bone chips thus both originate from the patient himself: they are autologous (synonym: autogenous). II. Production of the Bone ChipsOsteoblasts (bone-forming cells) are isolated from the periosteum in the clean room laboratory. In an initial phase of cell proliferation, in which the cells require blood serum as a nutrient medium, sufficient osteoblasts are produced within about 7 weeks. These are applied to a carrier substance known as a scaffold. The scaffold provides a stable three-dimensional scaffold for the further three-dimensional growth of the cell tissue and is later reabsorbed (degraded) by the bone. A fibrin gel, which is also resorbable, is applied to the biodegradable support matrix, and its function is to homogeneously distribute the osteoblasts in the support matrix. The bone chips have an area of about 1 cm² and are 2 mm thick. Each chip contains approximately 1.5 million vital osteogenic cells (living cells that stimulate the formation of new bone).III. Insertion of the Bone Chips

The bone chips are inserted into the area of the bone defect to be built up in a second surgical procedure. The sutures placed for wound closure are removed after 8 to 10 days.

After the procedure

Implant placement – In the postoperative weeks, the osteogenic cells form new bone substance. At the end of three months, the newly formed bone is sufficiently mature and load-bearing to allow implants to be placed. These, in turn, must heal for about three months before they can be loaded by the final tooth replacement, the so-called superstructure. To bridge the time, the gaps between the teeth are restored with temporary dentures, which are designed so that the implant area cannot be overloaded during the healing phase.

Possible complications

  • Pain – usually only moderate and temporary.
  • Swelling
  • Wound infection