Dental enamel is the hardest tissue produced by the body. It cannot regenerate itself, because it is formed by a layer of cells that is lost by the time the tooth appears in the mouth. The enamel spends the remainder of its lifetime vulnerable to wear, damage, and decay. For this reason, it is exciting to consider the prospect of artificially growing enamel, or even whole teeth, using culturing and transplantation techniques.
Consider how people wear braces to straighten teeth. Also, people get replacement crowns put on teeth. But instead of replacement crowns imagine braces that hold a covering over teeth and that inside the covering cells get inserted that can grow enamel. You'd wear enamel growing incubators over your teeth to build them back up after years of wear and tear. The existing teeth would get recapped periodically using the same types of cells that created the teeth in the first place.
Some Japanese scientists have made progress on methods to grow enamel-forming cells in larger numbers.
In the emergent field of tooth-tissue engineering, several groups have developed their own approaches. Although there has been some success in producing enamel-like and tooth-like tissues, problems remain to be solved before the technology comes close to being tested in humans. One of the issues has been how to produce, in culture, sufficient numbers of enamel-forming cells.
Today, during the 85thth General Session of the International Association for Dental Research, a team of researchers from the Institute of Medical Science, the University of Tokyo (Japan), reports on a new technique for culturing cells that have the capacity to produce enamel.
The scientists boosted cell growth by use of a special feeder cell layer. My guess: some day synthetic surfaces and drugs that serve in their place.
This group has recently shown that epithelial cells extracted from the developing teeth of 6-month-old pigs continue to proliferate when they are cultured on top of a special feeder layer of cells (the feeder-layer cells are known as the 3T3-J2 cell line). This crucial step boosts the number of dental epithelial cells available for enamel production. In the study being reported today, the researchers seeded the cultured dental epithelial cells onto collagen sponge scaffolds, along with cells from the middle of the tooth (dental mesenchymal cells). The scaffolds were then transferred into the abdominal cavities of rats, where conditions were favorable for the cells in the scaffolds to interact and develop. When removed after 4 weeks, the remnants of the scaffolds were found to contain enamel-like tissue. The key finding of this study was that even after the multiple divisions that occurred during propagation of the cells in culture, the dental epithelial cells retained the ability to produce enamel, as long as they were later provided with an appropriate environment.
Useful human treatments still lie years in the future. But these results provide hope for better dental repair solutions 10 to 15 years from now.
I expect the rate of increase in this research to accelerate as microfluidic devices, gene chips, nanomaterials, and other tools for working at small scales provide scientists with much faster and easier ways to manipulate and measure cells and cellular components.
|Share |||Randall Parker, 2007 March 24 01:53 PM Biotech Teeth And Gums|