Dentalnews (en)

Bone reconstruction – overview

We have already written several articles on the subject of bone reconstruction, click the following links to see them:
–

Iliac crest transplantation is not necessary

Human bone heals best

Dental implants and bone reconstruction

–

Now we would like to introduce an innovative new procedure, helping to prepare human bone for bone transplant!

One major problem is that bone replacement materials are often distributed through doctors and chief physicians at hospitals, who then of course get a percentage of the profits, making it difficult to get a truly „objective“ opinion. So you keep hearing great things about e.g. bone replacements made of algae, which does not really correspond to the facts.
–

–

But let us concentrate on human bone for now. Bone from human donors has always been, and still is, cleaned using liquid solvents. The problem with this process, however, is that you can never quite get the bone 100% clean, there are always some cell remains left. After the transplant is performed, the immune system of the recipient tries to break down these remains, leading to an inflammation, which unfortunately also ends up destroying the transplant.
–

Instead of solvents, the company Celtis uses highly critical CO2 to clean bone. This is a kind of aggregate state in which the CO2 is neither liquid or gas but somewhere in the middle.

Simply put, you are familiar with H2O in its solid state – ice, in its liquid state water and its gaseous state steam.
An aggregate state is referred to as highly critical when it is between two of these well-known states. CO2 in such a state retains both the excellent fat-soluble qualities of liquid CO2 as well as the excellent diffusion characteristics of gaseous CO2.
–

The result is a spanking clean piece of bone, as shown in the picture below after cleaning by Celtis – pure white, and on top of that bone cleaned the usual way, which has a yellowish tinge. The calcium structure of the bone, hydroxylapatite, is white, like that of the company Celtis!
Not only that, but Celtis also refines the bone using an antibiotic. This saves the patient the trouble of having to take antibiotics, receptor cells settle into the new „bone“, which is actually not much more than a calcium matrix, and soon enough the transplant has become a part of the recipient’s own bone – now that’s what we call progress!
–

More about this topic here!

–

–

–

–

What happens when a dental implant sticks out into the maxillary sinus?

Implants and bone reconstruction!
In order for dental implants to hold securely you need to have enough bone. But if a patient has been missing teeth for too long or suffered periodontitis, often there is not enough bone left in the upper jaw. An operation designed to reconstruct bone – called a sinus lift –  has to be performed before implanting.

–

–

–

Bone reconstruction in the upper jaw
Despite the most careful planning, implants sometimes end up sticking out into the maxillary sinus. Patients must be informed, as a lot of them get dental implants without realizing that the maxillary sinus got damaged in the process.

Is there a greater risk of losing an implant?
Sinus infections may represent a risk, even during a common head cold, implants may get infected due to the lack of a protective bone layer. Then you can lose an implant.
The picture shows a patient with implants in her upper jaw (to the right in the picture). The implants (black) clearly stick out into the maxillary sinus (blue). The patient was not told about this problem – even though the implants stuck out from the very beginning. The operation took place three years ago, right now there are no inflammations around the implants – but there are some in the rest of the teeth!

Using donor bones for bone reconstruction?

When a patient has gone without teeth for a long time or suffered from bouts of inflammation, the part of the upper and lower jaw-bones which support teeth has often been found to recede, leading to a diagnosis of „alveolar atrophy“.

–

Dental implants can no longer be inserted into the bone which is left, as this may cause damage to nerves and sinuses. The only solution is bone reconstruction, using either bone from the patient’s own body, or other materials.

–

Using bone from other places in the patient’s body involves performing additional operations, which is why many doctors prefer using other materials. As you may have read in the various articles we have written on the subject of „Bone reconstruction“ human bone heals much better than artificial products.
–

But where can you get human bone?

Human bone – or tissue in general – is taken either from corpses or is a by-product left over after operations (e.g. a fracture of the neck of the femur). There are strict laws in place for regulating and monitoring the removal of tissue and bone. For example, doctors cannot just take products left over after an operation without the consent of the patient, as legally this is still the „property“ of the patient.

–
Each country has its own laws with regard to corpses. Many countries have a donor database, in which people who want to donate have to sign up while they are still alive, so that organs and tissue can be legally removed after they die.
–

Other countries (such as Austria), take the opposite tack. They keep a list of objectors, meaning that organs and tissue can be removed from just about anybody after their death, who did NOT put their name on this list while they were alive

–

Although this may seem somewhat macabre to you, it should be obvious that this makes for a lot more organs and tissue and human life saved by organ transplants or ailments alleviated by tissue transplants. It should also be pointed out that these „removals“ may only be performed by institutions registered with and monitored by the government!
–
Whatever option appeals to you more from an ethical point of view, biological material shows much better results than does artificial material.
–

So what’s your opinion on using human bone?

What is the best type of bone to use in reconstruction?

If parodontitis goes untreated for a long time, or teeth are lost and not replaced, then bone starts to recede. And once it is time for a dental implant, there may not be enough bone matter available to support the implant.

Fortunately, there are various materials available to reconstruct bone, but which one of them is the best?

A rule of thumb is that the more similar replacement bone is to human bone, the better it heals. The best bone to use is the patient’s own – as long as the chunk of bone used does not exceed a specific size – you can find out more on that here.

From a certain size onwards it is better to use purified replacement bone, ideally human bone, or animal bone, for example from cattle. Bone substitutes can also be produced, e.g. from algae. Synthetic bone takes the longest to heal, although research is still being done on the subject.

It does not help to infuse bone from a donor with your own cells.

It is much more effective to mix replacement bone with your own blood – this is usually enough, and facilitates absorption during an operation, but it is unclear whether it helps healing.

There are many studies on this topic, but they are often poorly structured and do not observe evidence-based medical guidelines. Moreover, many of the materials used to replace bone are distributed by doctors themselves, and they all have their favorites, so it is hard to remain objective!