New method yields stronger tooth implants
Millions of people replace their bad teeth with implants made of titanium; but after surgery, many do not chew the food up to six months, until the implant has become fixated in the bone.
Now, for the first time, a drug coating that has been tested on humans allows titanium screws to adhere to the bone better and faster. The Linköping researchers behind the method report that the results are good.
The study, led by Per Aspenberg, professor of orthopaedic surgery at Linköping University, is published in the journal Bone and was highlighted in the British Medical Journal (BMJ).
The implants are screwed into the jawbone and provide purchase for artificial teeth. Using current technology, it may take four to six months before the bone surrounding the screw has healed and is strong enough so the patient can begin to benefit from surgery.
The coating, developed at Linköping University in Sweden, consists of a nanometre-thin layer of protein that attaches to the metal surface. Attached to the protein is a drug belonging to the bisphosphonates, usually used to treat osteoporosis. Several animal studies have shown that this method allows the bone surrounding the implant to rapidly become denser and stronger.
Now, for the first time, this method has been tested on humans. Sixteen patients each received two implants; one normal and a similar surface-treated implant as described above. Neither the patient nor the dental surgeon knew which was which. After six months it was noted that for 15 of the 16 patients the treated screw was markedly much better established. Already after two months X-ray images showed positive changes adjacent to the treated screws. No complications occurred.
"It is the first time ever anyone has succeeded in reinforcing the bone around an implant with localised medication," says Per Aspenberg, professor of orthopaedics, who devised the method of using bisphosphonates in this way.
Pentti Tengvall, professor of biomaterials, developed the method of adhering the drug to the screw and the study was conducted by Jahan Abtahi, specialist MD and PhD, supported by Per Aspenberg. Addbio AB is a Linköping based company now working on commercialising the surface treatment for different types of implants in bone.