10/23/2000 By Chris Smith
Managing Editor, E-dental.com
The year 2000 had several milestones for the U.S. space program, including the 100th launch of the space shuttle, with landing scheduled for today.
But within the space industry’s triumphs were some for the dental profession as well.
Earlier this year, the Shuttle Atlantis and seven astronauts set sail for the International Space Station, embarking on a mission to outfit the vacant outpost for its first full-time tenants and a slew of future construction crews.
Like a long-haul moving company, the Atlantis crew of five Americans and two Russians unpacked a shuttle cargo bay shipping container and a Russian space freighter now docked at the outpost.
They also unpacked more than three tons of supplies and equipment, including oxygen generation and carbon dioxide removal systems as well as exercise equipment, a toilet, tools and space station batteries. Among the supplies were two items one cannot live without – toothbrushes and toothpaste.
Seven more shuttle missions will follow by November 2001 to add key components such as power-producing solar wings and a U.S. lab that will serve as the scientific hub of the station. Seven Russian rockets also are to fly during that time, launching space taxis, supply ships and a docking compartment to the outpost. NASA officials are confident the new station will become an operational research park in the next 12 months.
If the past is any indication, the research conducted in the lab will provide crucial information to the dental profession.
NASA research leads to laser with dental application
A laser device inspired by NASA research on atmospheric conditions could provide an alternative to the dental handpiece and scalpel and would require no anesthesia for most patients.
Currently, separate lasers are required to work on hard tissue such as teeth to prepare the tooth for filling, and on soft tissue for gum treatment and oral surgery. Recently, though, researchers at Langley Research Center have demonstrated that the two laser wavelengths important to dentists can be produced from a single, system that is easier to use.
Both wavelengths can be produced using the same hardware, reducing cost and complexity. Switching between the two wavelengths is accomplished by selecting the amount and rate of energy sent to the specially-designed laser system. The resulting hardware is about one-half the size of two distinct laser systems and does not require the laser system to be “tuned” by the operator like typical present-day systems, according to NASA.
A typical hard tissue laser costs about $38,000 and a soft tissue laser costs around $25,000. The dual wavelength unit made possible by this new technology is expected to cost less than $30,000.
The discovery of the two-wavelength technology is a spin-off of work to develop high power lasers for remote sensing of the atmosphere, a key element in NASA’s atmospheric sciences mission.
The technology has also been used in aeronautics research including measurements of winds, wind shear and turbulence in flight and measurement of wake vortices from the ground in airport terminal areas. Those investigations led to the discovery that it is possible to selectively produce two or more useful wavelengths from a single laser source.
Panel addresses oral health of astronauts
A French study published earlier this year indicates that space travel is not good for an astronaut’s teeth and bones. Specifically it showed that space travel can reduce bone density after a month of weightlessness.
Laurence Vico and his colleagues at St. Etienne University called for more research into the effects of microgravity after their study of 15 cosmonauts from the Russian MIR station showed bone loss continued throughout the duration of space missions.
They measured the bone mineral density in the radius, one of the bones in the forearm, and the tibia in the lower leg of cosmonauts who had spent one, two and six months in space when they returned to Earth and again after a similar period on Earth.
The loss was significant in the tibia, which is a weight-bearing bone, but barely changed in the radius.
In the future, Dr. Vico and his colleagues say scientists should try to determine if the loss of bone density was only on weight-bearing bones on longer missions. The study has implications for dentistry, though researchers do not yet plan to study the effects of weightlessness on teeth or the jawbone, which holds teeth in place.
However, another agency may take on that task of investigating the effects of weightlessness on the oral cavity, though studies will have to occur under the auspices of the National Academy of Sciences’ Institute of Medicine Committee. Last April, the NAS took the first steps toward shaping a strategy for maintaining the oral health of astronauts when it decided to expand an existing program — under contract with NASA — to investigate the oral health of tomorrow’s space travelers.
The NAS/IOM panel also convened a workshop on “Space Dentistry: Maintaining Astronauts’ Oral Health on Long Missions” to raise questions toward meeting terms of the NASA-commissioned study.
The committee invited discussion on the available evidence and experience for an oral health strategy and heard more questions than answers. What impact will prolonged weightlessness have on dental plaque for example? On oral bacteria? Bone structure and function? Stress? How will dental care be provided, emergencies handled? What emergencies might be anticipated, what dental equipment necessary, useful and deployable in deep space?
One participant recommended the creation of a dental advisory team to include representatives of the military services, American Dental Association, National Institute of Dental and Craniofacial Research, dental specialists and NASA to address issues such as:
Ultimately, the panel is looking for two types of dental information, according to committee staff: evidence-based recommendations regarding oral diseases and conditions that might reasonably be anticipated during a three-year mission and suggestions regarding the necessary clinical research to prevent or address them.
However, though some of the questions about the effects of space travel remain a mystery until they are unlocked, in the future, one thing probably will remain the same. You will still need to brush your teeth in outer space.