KUALA LUMPUR: Scientists from Universiti Malaya (UM) have made a breakthrough in accelerating bone healing through new biomedical implants.
This major success will not only help lessen the procedure and post-surgery complications, but can also potentially lower the costs of such implants.
The two studies funded by UM’s High Impact Research (HIR) programme and the U.S’ National Science Fund involves 24-year-old Alireza Yaghoubi, who is HIR’s Young Scientist.
Bernama recently interviewed Alireza and Dr Muralithran Kutty from the Department of Restorative Dentistry of UM to find out how the breakthrough could vastly change the future of bone implants.
BETTER, FASTER, STRONGER
Those who have undergone orthopaedic or dental implants in recent years may have titanium parts implanted into their bones. As the human bone is calcium-based, it does not naturally bond with material like titanium. To chemically bond the titanium to the bone cells, scientists have come up with a bioactive ceramic coating that is calcium-based, so that it is similar to the human bone. This bonding process is called “osseointegration”. The calcium-based coating adheres to the bone very well. However, during the bonding process, the heat causes the coating to expand at a different rate than the titanium, and this causes micro cracks to develop.
“This mismatch in thermal expansion also causes delamination and affect load-bearing implants, such as in hip replacements. When pieces of the coating come off, it would act like sandpaper and abrade the bone“, said Alireza.
To address the problem, the scientists came up with two solutions.
One, was to geometrically modify the surface of the titanium using the “microwave technique.” This markedly improved the chances of good osseointegration in the early stages.
Not only is the new technique is much simpler than the existing methods, it also allows for implants to be personalised at a fraction of the time and cost of the current methods - all while offering higher mechanical reliability.
The scientists also developed a superior bioactive coating using magnesium silicates, which does not develop micro cracks. This would effectively prolong the durability of load-bearing implants, such as in hip replacements. It would also reduce chances of post-surgery complications.
ISSUES WITH DENTAL IMPLANTS
Dental implants are one of the biggest advances in dentistry in the past four decades. There are three phases to the procedure. Once the natural tooth is extracted or missing, the dentist surgically places the implant into the jawbone. The bone around the implant is then allowed to heal. Upon successful healing, an artificial tooth is made to fit over the implants.
Muralithran said the current practice was to send patients home after the titanium implant had been screwed into the jawbone, without loading it with the tooth crown.
Depending on the bone and oral health of the patient, it would take between three to six months for the implant to osseointegrate.
“If the patient has good bone density, the implant will osseointegrate very quickly. They can return within three months and have their tooth fitted in.
“However, those with poor bone density may return only to find that their implant has not set in properly, while those with poor oral hygiene may find an infection around the implant area. So the dentist would have to redo the surgery again.
“The key thing is to have the bone osseointegrate quicker so that the patients would not have to wait too long before putting in the load, risking infection and resulting in poor healing rate. We are hoping this breakthrough will contribute to rapid healing and lesser infection“, he said.
THE MICROWAVE TECHNIQUE
Muralithran said the current commercially prepared implants were pencil-sized titanium rods that were cut into standard shapes and sizes. The surface is treated with acid to create a roughness that helps bone cells attach to it.
However, having preset sizes meant that a patient would not be able to get an implant that would be the best fit. This would further affect osseointegration. The process of treating the implant surface with acid also increases time and cost of production, in addition to making it brittle.
The microwave processing technique addresses these issues.
“With microwave processing, you don’t start with a piece of metal but with powdered titanium. You then note the particular size needed by the patient, come up with a mould and put it inside a microwave for 20-30 minutes. The result is a custom-sized implant.
“While the conventional implants have to be treated with acid to obtain the ideal surface for bone cells to grip, the custom-made ones that were microwaved already have the surface porosity that would facilitate the process. You can directly use it after that“, he said.
Meanwhile, Alireza said that an interesting aspect of using powdered titanium is that the dentist would also be able to modify the surface topography of the implant by using powders of different-sized particles.
COMMERCIALISATION
Alireza said depending on the outcomes of clinical trials, it would be several years before the coating and microwaved implants become commercialised.
Would it be as costly as the currently available ones?
“The production of dental implants is currently very low as only a few companies produce it. When the technology grows and more people produce it using different methods, then the prices might go down.
“However, these two methods are not particularly expensive. The coating we came up with can be used to coat thousands of implants in a few minutes. I guess you can say the production might not be as expensive as the current technology as we can mass-produce it, instead of treating the implant one by one“, he said concurring with Alireza.
“We haven’t done the calculations but in principle, yes, it may be cheaper. But the more important thing is that it is a major improvement in quality. The patient can now get better, personalised implant.”
The World Health Organisation states that over a third of the world population would be over 60 years old by 2050. The trend is more prominent in Europe in Asia, making regenerative medicine one of the more active and well-funded research in developing nations in recent years. – Bernama