Ever wonder why dental implants are so much more effective than traditional tooth replacement options?
The main reason for this is due to a phenomenon known as osseointegration which is the structural connection that forms between your natural jawbone and the titanium implant. When compared to traditional tooth replacement options that aren’t connected directly to your jawbone, dental implants are far superior since they mimic the strength and functionality of a natural tooth.
Osseointegration was discovered by accident in 1952 by Swedish researcher Per-Ingvar Brånemark who was using titanium implant chambers to study the blood flow in rabbit bones. When the study was complete and it was time to remove the titanium chambers, Brånemark was unable to remove them because they had completely fused with the bone.
Now that scientists have had time to study this phenomenon we have a much greater understanding of how it works which we will explain further in this article.
How Does Osseointegration Work?
Osseointegration is a slow process which can take anywhere from 3 to 6 months to be fully complete. The entire process can be broken down to 4 phases described in detail below.
Phase 1: Hemostasis
Osseointegration begins as soon as a hole is drilled into the implant site and the titanium post is placed in contact with the jawbone. Once the site is drilled, blood vessels will be ruptured causing some minor bleeding and a natural response for the area to begin healing.
Within a few minutes, certain ions and serum proteins that leak out of the blood vessels begin adhering to the surface of the titanium implant. While this is happening, the blood vessels also start healing themselves by releasing thrombocytes which clump together to seal the ruptured area.
Fibrin monomers then begin to spread due to the blood clot created as a result of the healing blood vessels and attach to the implant surface.
Phase 2: Inflammation
Several hours after the surgery, cells that are responsible in the body’s immune function are released to clean chipped bone matter, tissues and oral bacteria from the wound.
Blood vessels then become more permeable causing endothelial cells to slightly move apart from each other. This allows for polynuclear leukocytes (pml’s) to permeate through the blood vessel walls and enter the wound.
As the pml’s arrive at the wound, they begin to kill bacteria by releasing oxygen species and highly digestive enzymes. Due to the high amount of bacteria in the wound, macrophages are also released to help kill bacteria through phagocytosis during the later part of the inflammatory phase.
Phase 3: Proliferation
A few days after surgery a cell found in connective tissue known as fibroblasts enter the wound producing collagen and other fibers. This stimulates the formation of perivascular cells which are a type of stem cell found on blood vessels.
As a result, new blood vessels are formed which are integrated in the existing vascular network. The oxygen supply is then restored allowing for bone healing to begin.
Around one week after surgery, a large multinucleate bone cell known as osteoclasts begin to absorb bone tissue, a step that is crucial for the healing phase. As the osteoclasts dissolve some of the bone structure with hydrochloric acid, certain byproducts are released which are necessary for the formation of new bone tissue.
The new bone tissue connects to the implant surface through collagen fibers which are attached to a thin protein layer between the jawbone and the implant. By the end of the first week after surgery, there is a new woven bone structure formed at the surface of the titanium implant which is very important for implant stability
Phase 4: Remodelling
Several weeks after surgery, the new bone structure will begin to remodel itself in a way that makes it very receptive to occlusal forces. This usually happens in the form of bone structures connecting to the titanium post at right angles.
As months pass by, lamellar bone structure begin to form, which is a parallel alignment of collagen, similar to the structure of pillars in a large cathedral. This formation of lamellar bone structure is very strong allowing for the implanted tooth to be fully functional.