test tube teeth

Tue, 28 Mar 2006 18:20:40 GMT

Sarah Goforth of Why Files online states Feb 4, 2004{http://whyfiles.org/shorties/147tooth/}, “A special talent lies behind a shark’s fearsome grin. When a tooth-among [their many] rows and rows-is lost, a fully-formed spare pokes through in a matter of days. Must be nice, humans get a measly two sets. And according to the National Institute of Health, by age 50, the average person has lost 12 teeth, and by 70 half of us are toothless all together. Luckily for those of us who’d rather hang onto our molars, scientists are nursing human teeth in the laboratory with new success. Someday, this may mean the end of crowns and dentures for taffy addicts everywhere. It could also mean an end to the boundless suffering—personal, social and economic—caused by tooth loss worldwide.” The national Institute of Dental and Craniofacial Research, notes that “tooth loss has been a public health problem in the United States since the days of George Washington and Thomas Jefferson. Despite revolutionary advances in oral health over the last half century, tooth loss remains a problem, particularly among disadvantaged groups. In addition, tooth agenesis-the lack of one or more permanent teeth-is the most common congenital malformation in humans. While dental implants or dentures are often effective replacements, science has progressed to the point that it may be possible to generate replacement teeth from scratch, which would mark a truly historic advance in oral healthcare and in our understanding of human biology.” Today we are going to examine the test tube tooth, how it works, and its future implications.

{the into story says this is the bibliography-
Tissue Engineering of Complex Tooth Structures on Biodegradable Polymer Scaffolds," C.S. Young et al., The Journal of Dental Research 81 (10):695-700, 2002.
"Development of teeth in chick embryos after mouse neural crest transplantations," Thimios A. Mitsiadis et al., Proceedings of the National Academy of Sciences, 100 (11): 6541-6545, 2003.

I-What is it?
Tooth regeneration, or the re-growing a tooth, begins with tissue engineering. Professor Paul Sharpe of the Dental Institute, King’s College London, stated to the 2004 News Archive that “Tissue engineering is the science of manipulating cells to form new tissues to replace damaged, diseased or missing organs. Although a relatively recent technology, it has had significant success in the replacement of skin, bone and cartilage. This science has been revolutionized with the advent of adult stem cells. Adult stem cells are ‘undifferentiated’ – that is, they have the potential to develop into many different tissues and organs when given the correct signals. The recent discovery of stem cells in adults opens up the way to use these cells…to grow new organs – avoiding any rejection problems.” And as stated in the British Dental Journal 2003 once tissue engineering has been accomplished, test tube teeth are the results from being able to “manipulate [these] genes that influence the initiation and patterning process during early tooth development”.

II-How it works:

Now that we understand what the test tube tooth consists of we can explore how the craft it. First, in order for us and scientist to begin generating transplant teeth, they/we need to comprehend how the tooth is formed. The August 2005 issue of Scientific American states, most organs…arises through interactions between two distinct embryonic cell types, epithelial and mesenchymal and teeth are no exception. In the embryo, oral epithelical cells, (which are destined to line oral cavities) send out the first inductive signals to mesenchymals cells, (which will produce jawbone and soft tissues), instructing them to begin odontogenesis, or tooth formations.” The mesenchymal cells send signals back to the epithelial cells. “This communication continues throughout the embryonic tooth growth.”

With this understanding, Joseph O Vacanti an organ transplant surgeon of Harvard medical School and polymer chemist Robert S Langer of the Massachusetts Institute of technology though of a brilliant idea: “their approach was based on the fact that living tissues are made of cells constantly signaling to one another and often moving around within a three-dimensional community of sorts. Each cell seems to know its place and role in the larger collective that forms and maintains a functional tissue. Therefore, if the right mix of dissociated cells is reaggregated within a scaffold that replicates their natural 3-D environment, the cells should instinctively reform the tissue to which they belong.” Although this is a brilliant plan and approach, their theory turned out to be easier said than done; that is until the past few years.

Recently Paul T Sharpe and Conan S Young founded a biotechnology company devoted to growing human teeth and bone called the Odontis Ltd. This group has to date “aggregated mesenchymal cells in a centrifuge until it formed a small solid mass. (Then) this pellet was covered in epithelium and cultured for several days, while the gene activity in its tissues was monitored for indications of early tooth development. Next these tooth primordial were implanted into the bodies of animal hosts in locations where they could receive a nourishing blood supply…and left to grow…In the course if these experiments, clear tooth formation was observed…these teeth were in the normal size range for mouse teeth, were surrounded by new bone and connection tissue, and showed the earliest signs of root formation.” The next question was can these generated replacement teeth be inserted into a jaw without rejection. The preciously sited Scientific American states, “ The embryonic tooth primordial were inserted into these pockets and sealed in place with surgical glue. After ward, the mice were fed a soft rissue diet and the transplants identified in the diastema. They had formed in the correct orientation, were of appropriate size for mice, and were attached to underlying bone bye soft connective tissue.” Abc news science online, last accessed March 26, 2006, Sharpe explains his confidence, "If we can do it in a mouse, and prove up the principles, it should be much easier in humans because of the size…” he continues "We know we can do many of the bits. We've yet to do them all together. But in about two years, we should be ready to start on human patients."

III-Future implications
Now that we understand what the test tube tooth is, and how it is created we can examine the millions of people the test tube tooth we affect. Science Daily last accessed March 19, 2006 reports that, “In the US more than 20 million people are missing their natural teeth, with more than 100 million people missing 11-15 teeth.” This does not even take into consideration the potentially billions of people out side of the United States. Yet “In 2001 there were more than 252,000 implant procedures in the US.” With artificial implants so commonly received it is only natural that the test tube tooth can aid several million people to re-grow their own teeth. Unfortunately, many people do not realize the severity of permanent tooth loss. Tooth loss and or decay leading to a removal of a tooth leads to many other problems. Dr. David Barnet, a practicing density, stated in a personal interview March 27, 2006, that “once a permanent tooth is lost the teeth on either side gradually and tilt toward the gap, and the teeth in the opposite jaw begin to slip vertically toward the space. This may lead to periodontal disease, so missing teeth ideally need replacement. (In addition) tooth loss affects a person’s nutrition. People may be unable to eat certain foods, like meats and hard fruits and vegetables. And finally, tooth loss drastically affects speech. Without teeth, people would have a hard time enunciating words. If the teeth are not replaced, a person’s overall health and demeanor would be affected.” The test tube tooth is the perfect solution to all tooth loss world wide. And with because the global dental implant market is forecasted to grow at around 15-20% per annum for the next 5-6 years, let us all join together and grow back our own teeth. With this increase of implant market this mean’s that the market will rise from US$900 million at present to around US$1.5 billion by 2007. That is just one year away…I DON’T KNOW WHERE TO GO FROM HERE…

Today we have examined the test tube tooth, explored how it works and finally seen how many people worldwide we can provide new pearly whites for. (say something good for a last thought) and now everyone smile and say cheese.

I think we need to talk about how it is possible to grow organs. Chris thinks the same thing…I know you are scared that it will sound like yours but Chris says no one remembers that “shit. Erica Widmer had a drama that she golded at states and it was done last year…that gold still tastes the same.” –totally his words. But I agree I don’t know your speech nor did I know of it ya know. Let me know.

Could go quotes-
1- The American Associating for the Advancement of Science states, “researchers are closer than ever to the test tube tooth. Specifically, they are harnessing do-it-all stem cells to re-create the tooth buds that form in the early embryo. The idea is to implant these “primordial teeth” into human jaws and let the cells take it from there. Using patient’s own stem cells bypasses the rejecting problems that so often happen in ordinary transplants.”

2-
Two years ago scientists at the National Institutes of Health near Washington DC showed that the tiny pulp chamber inside every tooth contains stem cells capable of becoming dentine-producing cells called odontoblasts. The scientists estimated that out of the millions of cells in a tooth's pulp chamber, about 80 will be stem cells. Another team at Texas University Dental School has discovered a source of the epithelial cells which give rise to enamel inside adult mouse teeth. When these cells are grown alongside dental pulp stem cells, dentine-enamel structures form. Professor Sharpe is using stem cells, but will not say which ones. By finding the right signalling molecules he has persuaded stem cells from adult mice to develop into tooth progenitor cells and immature teeth. He does not believe tooth development is too complex to emulate. "Yes, it's complicated, but we are letting the natural embryonic development pathways do the work for us." (BBC news august 7 2002)

speech help

test tube teeth