In this blog post, we will explain in simple terms the process of osseointegration, which is how dental implants bond with bone, and its importance.
Humans have been trying to replace missing teeth for a very long time. In the 19th century, the technique of prosthetic teeth made of gold was developed, and in the early 20th century, attempts to create dental implants began. Then, in the 1980s, a technique similar to modern dental implants was introduced for the first time.
What are dental implants? Medically, an implant is defined as “an artificial object implanted into the body to replace a missing body part.” Implants can be used in various parts of the body. For example, there are skin implants and ear implants. Among these implants, those inserted into teeth are called “dental implants.” As shown in the photo above, dental implants are metal screw-like materials implanted into the area where the root of the tooth should be, and then a “crown” shaped like the upper part of the tooth is attached to the top of the screw. Before the development of modern implants, dentists faced a major challenge. This was because old-style implants were not functionally connected to the gums and could not transfer force to each other, resulting in poor tooth function. Therefore, it was necessary to find a material that could be structurally and functionally bonded to the gums.
In 1952, Swedish physiologist Professor Branemark was observing the wound healing process of a rabbit’s shinbone under a microscope. Professor Branemark discovered that titanium placed in the wound area was surprisingly completely fused with the bone tissue. Professor Branemark called this phenomenon “osseointegration.” This process of “osseointegration” was immediately applied by dentists and used in the development of modern dental implants. What is the principle behind osseointegration in the dental implant process? And why is titanium used for osseointegration?
Think back to your school days. What was the atmosphere like in your class at the beginning of a new school year? Students who were in the same class the previous year would stick together, and it would be difficult for the whole class to integrate. However, as time passed and the school year came to an end, all the students in the class would become friends, regardless of what the class was like the previous year. The process of osseointegration is similar to this. When titanium is first inserted into the gums, it is separated from the tissue because it has not yet bonded with the bone. After inserting the titanium and waiting, a very strange change occurs in the human body. First, the bone tissue begins to attach to the titanium and grow. When this happens, blood vessels and other body tissues bond with the titanium and become solid. Why does this happen?
When performing implant surgery, the gum is drilled with a dental drill. The blood from the drilling solidifies inside the gum and forms a hematoma (blood clot), which contains platelets. This is the same phenomenon that occurs when you fall while running and your skin is scraped, forming a scab. The “growth factors” released by the platelets in the hematoma stimulate bone tissue activity. Growth factors stimulate undifferentiated cells in the surrounding area that have not yet differentiated into bone tissue, causing them to differentiate into bone tissue. They also stimulate other types of cells to absorb damaged bone tissue. In addition, under the influence of these growth factors, new blood vessels grow, and the area where the hematoma was gradually replaced by blood vessels.
So why is titanium used as a material for bone fixation? The short answer is that titanium is the most biocompatible material available. Titanium has been found to be rust-free and non-toxic to the human body, and its high corrosion resistance makes it highly biocompatible. Corrosion resistance means that it does not corrode easily. The exact name of the material currently used in dental implants is titanium-aluminum-vanadium alloy (Ti-6Al-4V). Observing the surface of this alloy under an electron microscope reveals why this material is so effective at promoting osseointegration. The surface of the alloy has many holes, allowing bone to grow into them and blood vessels to grow. This is why implants can bond firmly to the gums.
Considering the process of bone fusion, implants and natural teeth have many similarities. Therefore, implants are not permanent like natural teeth and require ongoing maintenance. The old Seoul City Hall building must have been very beautiful and sturdy when it was first built. However, it is now so old that a new Seoul City Hall building is being used. The same is true for implants and natural teeth. If implants are well maintained, they can easily last for more than 30 years. However, if they are not well maintained, problems such as inflammation around the implant may occur, requiring replacement. Many people think that implants are artificial and do not require maintenance, but this is not the case.
Currently, dental implant technology is so advanced that it is difficult to distinguish between a dental implant and a natural tooth with the naked eye. As a result, dental implants have become a dental device used by many people, with 500,000 implant procedures performed in Korea alone each year. Dental implants have a variety of uses. Implants are often made simply for cosmetic purposes, but they are also used to make dentures more secure and beautiful, and are a tool often used in facial reconstruction surgery. Dental implant technology has the disadvantage of not having the muscles that connect the teeth and gums found in natural teeth, but it is the most natural-looking technology among all dental prosthesis technologies developed to date.
