Dental surgery might become easier...

[~MaryO~]

Source: http://news.xinhuanet.com/english/2005-02/...ent_2538750.htm

 

Dental surgery might become easier with new growth hormone injection technique

 

Today, when dentists replace a tooth, they also have the complicated task (painful for the patient) of building a bone structure around the new tooth. They typically transfer excess bone material to the tooth from other areas of the patient's face. But some University of Michigan researchers may have found a better way. The scientist used gene therapy to inject a growth hormone into the mouths of lab mice, and the hormone coaxed bones into growing by themselves.

 

LOS ANGELES, Feb. 2 (Xinhuanet) -- US Researchers have found that introducing a growth factor protein into a mouth wound, using gene therapy, helps generate bone around dental implants, according to a paper in the Molecular Therapy journal published on Tuesday.

 

US Researchers have found that introducing a growth factor protein into a mouth wound, using gene therapy, helps generate bone around dental implants. (yahoo.com) For a patient with a sizable mouth wound, replacing a tooth means more than simply implanting a new one. The patient also needs the bone structure to anchor the new tooth in place.

 

Such reconstructive surgery today involves either taking a bone graft from the patient's chin or jaw, which leaves a second wound needing to heal, or using donated bone from a tissue bank, which yields unpredictable results.

 

A team of researchers at the University of Michigan led by Professor William Giannobile delivered the gene encoding for bone morphogenetic protein-7 (BMP-7) to large bone defects in rats, in an attempt to turn on the body's own bone growth mechanisms.

 

The study showed that the animals produced nearly 50 percent more supporting bone around dental implants after getting BMP-7 treatment.

 

BMP-7 is part of a family of proteins that regulates cartilage and bone formation. Recent studies have shown that BMPs are present in tooth development and periodontal repair. The Michigan study mixed BMP-7 genes with an inactivated virus in a gel-like carrier and injected it into wounds. Researchers said using a virus, with the harmful effects turned off, harnesses the virus' ability to enter into cells and use their genetic machinery.

 

Once inside the cell, the viruses help BMP-7 genes get where they need to be in the host's cells to boost bone production. Gene expression producing BMP-7 proteins peaks after a week. The gene acts quickly to get bone growth started, then disappears within about 28 days.

 

Scientists said a next step in this process could include looking for non-viral approaches to delivering gene therapy to the defect site. Alternatively, they could conduct the gene therapy outside the body using a tissue biopsy and then transplant the genetically modified cells back into the patient. But this would require two surgical procedures instead of one.

 

"This study represents a proof-of-concept investigation. We are encouraged about the promise of this treatment," Giannobile said, adding that more work is necessary before the approach can be tested in humans.