Dental Radiation : Some Questions Answered?

Rarely does a week go by in the office without a question being asked about radiation exposure due to dental xrays. There is alot of misinformation readily available from family, friends and the internet. The information below is from the Health Physics Society. They are generally considered specialists in radiation safety.

Dental Patient Radiation Q & A

Q: I had a dental x ray while I was pregnant. I am worried that my unborn child might have been exposed to the radiation. Can you please tell me if there are any risks to my baby from this?

A: There is no information suggesting any risk to an unborn child from dental x rays received by the mother. When a pregnant patient undergoes a complete dental x-ray examination, the radiation dose to the fetus is insignificant. And, by the way, it does not matter whether a lead apron was used or not.

Q: Is there anything like a CT scan for teeth?

A: A couple of years ago a dental CT scan was introduced into this country. This is a growing field. The technology is commonly referred to as Cone-Beam. There is a lot of discussion going on now regarding the merit of diagnostic quality vs. the radiation dose.

Q: I am concerned about a crown put on my tooth in about 1992. I read some information that at one time uranium was added to the porcelain in dental crowns. What are the risks if there is uranium in my crown?

A: It is true that very small amounts of uranium were added to dental porcelain from the early 1900s through the 1970s. However, according to the Center for Devices and Radiological Health, US Food and Drug Administration, the last of the US manufacturers of dental porcelain phased out the use of uranium in the early 1980s. The original reason for adding uranium in the first place was to make the ceramic look more natural by increasing the fluorescence. However, other materials have been found that work even better and thus the use of uranium was voluntarily withdrawn, even before the new regulations took place. Thus it is highly unlikely that your crown contains any added radioactive material.

Q: Is there residual radiation in a room after a dental radiograph has been taken?

A: X rays cease to exist when the machine is switched off, much like the light from a light bulb when it is turned off. No residual radiation remains.

Q: How much has dental x radiation been studied and how concerned should I be about having dental x rays done? Is there a limit on how many I can have?

A: We now have very complete information on patient radiation doses from dental x rays. They are among the lowest radiation dose exams of any diagnostic radiologic procedure in the healing arts. Current practices deliver patient doses from a full-mouth series of intraoral films (usually 14-18 films) that are less than what a person receives in a month from natural environmental sources (commonly called background exposure). Doses from bitewing or panoramic films are even less. New technology is reducing the doses still further.

There is no limit on how many dental x rays you can have. The decision to have a dental x ray is based on the benefit of knowing whether or not there is a cavity, crack, or some other abnormality. So the decision to have them is based on what you and your dentist think.

Q: I am looking for publications regarding dental radiation safety. Can you help?

 

A: In 2003 the National Council on Radiation Protection and Measurements published Report No. 145, "Radiation Protection in Dentistry," which provides guidelines for radiation protection in dental practices. Generally, a state Department of Health (DoH) regulates the radiological practice portion in dentistry so you might check with your local state DoH. Its rules and regulations typically discuss training for individuals who operate x-ray equipment, equipment quality assurance, etc.

Also, take a look at the websites shown below. The American Dental Association and American Dental Hygienists' Association sites provide information regarding continuing education, accreditation standards, and patient information related to dental radiography. You'll also be able to do a literature search on MEDLINE via the National Library of Medicine page.

• American Dental Association
• American Dental Hygienists' Association
• National Library of Medicine
• American Academy of Oral and Maxillofacial Radiology

A quick search on www.amazon.com resulted in several books, including Essentials of Dental Radiography for Dental Assistants and Hygienists (by Orlen Johnson), Radiation Protection in Dentistry: Recommended Safety Procedures for the Use of Dental X-Ray Equipment (unfortunately out of print), and Radiation Protection for Dental Radiography (by Cris Edwards, but also out of print).

Q: I recently was having a panoramic x ray when the machine got stuck on my shoulder about halfway through completing its arc. The dental hygienist released me in about 10-20 seconds. For the time between when the machine was stuck and when the dental hygienist released me, was I being exposed to radiation?

A: For a panoramic dental x ray, the beam is operating continuously as it makes the image. All panoramic x-ray units have a "deadman" switch or button that must be continually pressed by the operator to producex rays. The production of x rays will stop immediately when the button is released. So, x rays are produced until the hygienist releases the button. It is likely that the button was released immediately because it is also required that the hygienist constantly observes the operation of the unit so that he/she can stop the radiation if the unit fails to rotate properly or if the patient moves. Even if it took the hygienist a second or two to realize what occurred and release the button, the radiation dose would be insignificant.

Q: What is the radiation dose difference between using standard film for a dental x ray and using digital radiography?

A: For intraoral radiographs (film packets placed inside the mouth) such as bitewings and periapicals, there are several types of film available at different speeds, meaning that they require different amounts of exposure to produce an image. This is a concept similar to photographic film speeds, with higher numbers requiring less light. A typical skin exposure for Group D film (ultraspeed) is about 300 mR, for Group E (Ektaspeed) about 150 mR, and for Group F (Insight) about 110-120 mR.

One digital-imaging manufacturer recommends setting the exposure for its equipment at about 20% of D-speed film, or about 60 mR. Another study found a 31-39% decrease compared with E-speed film for a different particular sensor. Some institutions have found that approximately a 50% decrease from F-speed film provides a good image.

One of the reasons that there is not much published on the specific amount of dose reduction is that most digital systems can use a fairly wide range of exposure times and then use software adjustments to provide a good image. It is possible that digital imaging may require as much exposure as film if the user does not consciously reset the x-ray machine to lower exposure or if the x-ray machine timer cannot accommodate the short exposure times (usually an old machine, not the current models).

With respect to digital panoramic radiographs, there appears to be no dose reduction compared with film-based panoramic images because there is already a large dose reduction as a result of use of intensifying screens in the panoramic cassettes.

Q: I recently had some dental x rays and the operator forgot to place the lead apron on me. Is this a problem?

A: Use of the lead apron to protect the patient undergoing dental radiographic examination was recommended some 50 years ago, when equipment was crude. This was because x-ray beams were not restricted to the area of clinical interest, beams were not filtered, and x-ray film was slower, causing radiation exposures 10 to 100 times higher than received today. With the current technology reducing radiation exposure significantly and the beam limited only to the area of interest, there is little or no measurable difference in whole-body dose whether a lead apron is used or not. The lead apron is no longer regarded as essential although some consider it a prudent practice, especially for pregnant and potentially pregnant females.

Q: I had several dental x rays taken recently and am now having problems with my gums feeling hot and, in some areas, getting sores. Is it possible the dental x rays caused this?

A: The amount of radiation needed to cause biological effects is several hundred times higher than can be received during dental radiography. Because of the design of these x-ray machines, there is a limit to the amount of exposure possible during the procedure. Diagnostic dental radiation doses are very small and not known to cause biological effects of the type you describe or any other type.

Q: Why do dental hygienists leave the room for each x ray?

A: It is general practice and in many cases a regulatory requirement for the dental technologists to leave the immediate area during the x-ray examination. Since the technologists are exposed repetitively to small amounts of radiation scattered from the large number of patients having dental x rays, it is considered good practice to reduce any risk they may have to an even smaller value.

Q: Because of the location of a local dentist office, I used to live and work in a room next to the room containing the dental x-ray machine. Was I being exposed to radiation?

A: Exposure rates decrease rapidly with distance. Ordinary walls generally provide sufficient shielding for these machines. In fact, it has been considered "safe" for operators of these machines to be in the room as long as they were at least six feet from the x-ray tube. If you received any exposure, which is unlikely, it would be an insignificant amount.

For the person who has everything: a $300 toothpaste squeezer?!?

From online men’s retailer, Park and Bond, this handcrafted chrome-plated toothpaste squeezer, made in Italy, is quite possibly the ultimate oral health accessory that no one needs, but everyone would want to try.

Tooth decay takes a licking?

A recent study, published by the European Academy of Pediatric Dentistry, demonstrates that sugar-free lollipops containing licorice root extract significantly reduced the bacteria that causes tooth decay, specifically in preschool children with high-risk of tooth decay.

The study, funded by the Research and Data Institute of the affiliated companies of Delta Dental of Michigan, Ohio, Indiana, Tennessee, Kentucky, New Mexico and North Carolina, analyzed 66 preschool students ages 2 to 5 enrolled in the Greater Lansing Area Head Start Program. Each student received a lollipop for 10 minutes twice daily for three weeks.
"Dental decay is one of the most common childhood diseases with more than half of children ages 5 to 17 having had at least one cavity or filling," said Jed J. Jacobson, DDS, MS, MPH, chief science officer at Delta Dental.
"We are working to find simple, effective regimens that will encourage prevention and control of dental disease. While the results of this pilot clinical trial are encouraging, more research is needed to confirm these early findings."
Results showed a significant reduction in Streptococcus mutans (S. mutans), the primary bacteria responsible for tooth decay, during the three-week period when the lollipops were being used and lasting for an additional 22 days before beginning to rebound.
Using a saliva test, the amount of S. mutans in the patient's mouth was measured before and during the three-week period where lollipops were used, as well as for several weeks thereafter.
"The use of the licorice root lollipops is an ideal approach as it will stop the transfer and implantation of the bacteria that cause dental decay from mothers to their infants and toddlers," said Martin Curzon, editor-in-chief, European Academy of Pediatric Dentistry. "It also has the merit of being a low cost-high impact public dental health measure."
Added Jacqueline Tallman, RDH, BS, MPA, principal investigator of the study: "This study is important not only for dental caries prevention research, but also demonstrates the feasibility of a classroom protocol using a unique delivery system suitable for young children. Early prevention is key for lifetime oral health and effective innovative protocols are needed."
The investigation was a collaborative effort of the Greater Lansing Area Head Start Program, the University of Michigan and the University of California-Los Angeles (UCLA). Delta Dental's Research and Data Institute provided the grants as part of its mission to remain on the cutting edge of finding solutions to oral health problems.
"Our Head Start program was excited to participate in the lollipop project," said Teresa Spitzer, RN, health programs manager, Capital Community Head Start-Head Start and Early Childhood Programs.
"Staff and parents were intrigued by something as simple as a special lollipop having the ability to decrease the incidence of dental caries in children. The outcomes only reinforced the value the parents placed on the project."
Lollipop fights decay
The lollipops, manufactured by Dr. John's Candies of Grand Rapids, Mich., were developed using FDA-approved materials by Dr. Wenyuan Shi, a microbiologist at UCLA, and C3 Jian, a research and development company in California. The orange-flavored, sugarless lollipops contain extract of licorice root (Glycyrrhiza uralensis), which targets and is thought to kill the primary bacteria (Streptococcus mutans or S. mutans) responsible for tooth decay.

Sleep Apnea May Cause Dementia

Findings published in the Journal of the American Medical Association showed what sleep specialist have long suspected, that sleep apnea can deprive the brain and other organs of the oxygen they need. Over time this triggers a decline in cognitive ability.

"This is the first study to show that sleep apnea may lead to cognitive impairment," said study leader Kristine Yaffe, MD, professor of psychiatry, neurology and epidemiology at UCSF. "It suggests that there is a biological connection between sleep and cognition and also suggests that treatment of sleep apnea might help prevent or delay the onset of dementia in older adults."

The UCSF study had 298 subjects that began without dementia or a decline in cognitive abilities, which allowed the researchers to measure the relationship between sleep apnea and record the progress of individual’s cognitive skills.

Using sophisticated computerized data researchers were able to monitor brain activity, oxygen concentration, heart rhythm and airflow. The instruments allowed the researchers to monitor apneas or hypopneas (reduction of airflow) of 30 percent or more.

After compiling data from the participants, Yaffe and her colleges found that about one third of all the women developed dementia or mild cognitive impairment. Researchers found that women with sleep apnea had twice the likelihood of becoming cognitively impaired.

The findings suggest that the key factor leading to diminished cognition was oxygen deprivation, also called hypoxia. Women who had frequent episodes of low oxygen or spent a large portion of their sleep time in a state of hypoxia were more likely to develop cognitive impairment. By contrast, no independent connection was seen between dementia and the number of times patients were awakened in their struggle to breathe.

The most effective treatment for the nighttime breathing disorder known as obstructive sleep apnea is the continuous positive airway pressure (CPAP) machine, according to a new report by U.S. Agency for Healthcare Research and Quality (AHRQ)

A CPAP machine pumps air through a mask while the patient sleeps. This treatment is highly effective in improving sleep and reducing symptoms of obstructive sleep apnea, according to the review of available evidence.

The report also found that one other treatment — a mouthpiece called a mandibular advancement device (MAD) — can be highly effective for sleep apnea patients. The device moves the jaw forward and keeps the airway open.

For further information on this or with any other questions, please give our office a call at 714-990-3672.

Paramedics are now using CPAP

The following excerpt appeared in the Riverside Press-Enterprise. CPAP devices which is normally used to treat sleep apnea are now being used by Riverside County paramedics with a mixture of patients that are having difficulty breathing.

Since April, all paramedics in Riverside County have been using continuous positive airway pressure devices, known as CPAP, on patients who have signs of congestive heart failure. The condition can cause patients' lungs to become congested with fluid, making it difficult for them to breathe.


The CPAP device being used in Riverside County consists of a mask that straps snugly to the patient's face, creating a seal around the mouth and nose, attached to an oxygen tank that pushes air into the patient's lungs.


These types of devices originally were used to help people with sleep apnea, Riverside County Fire Department officials said. The condition involves pauses in breathing while a person sleeps.


Now, CPAP is used in hospital intensive care units and emergency departments, in addition to its use by paramedics, they said.


Battalion Chief Phil Rawlings said the devices his department is using cost about $60 apiece and must be replaced after each use. Outfitting all 96 stations -- including initial startup expenses -- cost about $39,000, Rawlings said.


From April through early July, Rawlings said, paramedics from his department used the devices on 48 patients. All benefited from the procedure, some dramatically, Rawlings said.


"We're really, really pleased with it," he said.


The new equipment was mandated for all Riverside County paramedics by the Riverside County EMS Agency, which designs, implements and oversees the county's emergency medical services system, Director Bruce Barton said.


Elsewhere, CPAP has gained widespread use among paramedics in the past three years, he said.

The Snore Patrol Lies Outside Your Door

The following was an article written by Matthew Edlund, M.D in the Huffington Post:

Snoring is not normal. Markedly interrupting sleep, it's associated with increased heart attack and stroke risk. Prolonged snoring eventually leads to sleep apnea -- "stopped breathing" episodes that can put the individual's life at risk.

And snoring is often loud. It wakes up other people, particularly spouses. This can put a marriage's survival at risk.

It also wakes up hotel guests -- a lot.

Not Yet Coming to a Hotel Near You

Crowne Plaza has recently received much press for starting its own "snore patrols" and snoring absorption rooms, fitted with special soundproofing and white noise generators, as reported in Reuters. However, the U.S. has been left out thus far. The snore patrols have started in a few British cities, and the snoring absorption rooms have been set up in Europe and the Middle East.

Why Are They Doing It?

Though it sometimes seems as though the rest of the society does not yet get it, rest is critical to human regeneration -- and overall function and productivity. Hotel guests kept up by snoring become unhappy, as they regard a good night's sleep and a restful atmosphere as requirements of any hostelry. They may not want to come back. And Crowne Plaza has also set up "quiet zones", floors for people less prone to carousing who desire calming rest. The "snore patrols" will be particularly careful to keep these quiet zones quiet.

What Happens When the Snore Patrol Rouses a Loud Snorer?

They will presumably be asked to move to "non-quiet" zones -- though doing so in a full hotel at 3 a.m. may prove a stretch. In Europe, they may be moved to "snore absorption" rooms, although room availability will remain an issue.

What Is the Two Motel Rule?

The "Two Motel Rule," a.k.a. the Two Hotel Rule, declares that when someone is sleeping loud enough to be heard not only in their motel but in the motel next door, highly problematic snoring is present. People who snore this loudly should quickly consider seeing a sleep specialist to investigate possible sleep apnea.

Why Is Snoring Such a Problem?

1. It's common. There are estimates that about 25 to 40 percent of adults snore fairly loudly.
2. It's bad for your health. Snoring is complicated. There are a lot of muscles up in the back of the mouth, which has made treating snoring with electrical devices -- with the exception of CPAP, a direct air splint -- very difficult to manage. Most people don't enjoy having electrodes stuck up the back of their throats while they're trying to sleep, though the technology is improving.

What Makes Snoring Harmful?

Snoring appears to desynchronize breathing and circulation. When the two are out of whack, as occurs in sleep apnea, all kinds of bad stuff may happen, including potentially dangerous arrhythmias, lower cardiac output, autonomic dysfunction and a lot more awakenings from sleep which is bad for memory and learning. CPAP machines are effective for both snoring and sleep apnea, in part because they work to create a rhythm that allows circulation and breathing get back in sync.

What Else Increases Snoring?

Two big factors are alcohol and weight gain. Extra weight makes one more prone to snore. And alcohol, by lowering muscle tone and generally disrupting brain function, can produce far more snoring as well as severe apneas in people otherwise lacking evidence of illness.

One clinical history immediately comes to mind. When I was teaching at Brown, I saw a 30-year-old woman in the ICU with sudden respiratory failure. She drank a lot of vodka on her 30th birthday, developing severe apneas that left her unable to breathe. After the alcohol left her system the apneas stopped. (Note: People don't realize that there is a circadian rhythm to all drugs, and alcohol has 2-3 times the psychomotor effects at midnight than it does at 6 p.m. Have that glass at dinner, okay?)

As for weight, I usually try to control snoring in people through getting them to more effectively regenerate their bodies through engaging food, activity, rest and socialization in a pattern that fits their body clocks and makes it easier for them to get slimmer. One simple rule of thumb is to move after meals. Sleeping position also helps -- many folks snore less sleeping on their sides.

The Bottom Line:

Snoring is both a public and private health problem, which is why we are seeing the emergence of new hotel snoring policies. Besides waking others, snoring may injure you through sleep apnea and cardiovascular disease -- or poison your relationship with people you love. Desynchronizing breathing and circulation is not good for you.

So try to regenerate your body is such a way as to reduce or prevent snoring -- and deflect the unwelcome attentions of the corridor pacing snoring patrol.
 

Alcohol For Sleeping, Think Again.

Alcohol has some surprising affects on your ability to sleep.

Do you typically finish out your evenings with glass of wine, beer or even a shot to ease into sleep?

Consuming alcohol near bedtime can have a powerful, negative impact on your sleep quantity and quality. The effects of alcohol on sleep are apparently not common knowledge. A 2009 study found that 58 percent of 2,000 respondents were unaware that drinking can be detrimental to sleep.

Alcohol generally acts as a sedative and a small amount can and will induce sleepiness. Essentially, alcohol functions as a rapidly absorbed, relatively fast acting drug that gets to your brain within a few minutes. The drug metabolizes quickly and its effects pass within a few hours, depending on how much alcohol you consumed.

Using alcohol to get to sleep is by no means a new concept. Despite advances in sleep medicine, many people with trouble initiating or maintaining sleep self-medicate with alcohol and accept the consequences of fitful or unfulfilling sleep. In fact, it was not that long ago that physicians recommended "night caps" for insomniacs or others experiencing sleep problems. Using alcohol for sleep is a bad idea because it can affect sleep stages, lighten sleep and cause abrupt awakenings. Chronic use of alcohol may lead to needing higher and higher doses to achieve the same sleep-inducing effect.

The Sleep Cycle and Alcohol

Normal sleep consists of four stages that cycle throughout the night.

N1. The first step into sleep, N1 accounts for 4-5 percent of nightly sleep and functions as the brief transition period between sleep and wakefulness.
N2. A more consolidated stage, during which time your breathing pattern and heart rate begin to slow.
N3. Commonly known as "deep sleep" this is the stage when your body and brain are undergoing restoration.
REM. During REM sleep we often have action packed dreams. Parts of our brain are most active during the REM phase of sleep. Our muscles are essentially paralyzed during REM, preventing us from acting out dreams.
Sleep scientists have not determined all of the functions of sleep or the value of the various stages. All sleep stages are important and it is not possible to place more value on one stage or another.

Alcohol and the Sleep Stages

How does alcohol influence or change your sleep?

Alters the quality of your sleep. Even if you sleep a full night after drinking, you may not feel rested in the morning. Alcohol lightens sleep and suppresses REM.
Disrupts the total time you are asleep. You may wake up frequently throughout the night and have problems falling back asleep as the alcohol works through your system.
Increases the prevalence of pre-existing sleep disorders. Millions of Americans suffer from obstructive sleep apnea, which can intensify after alcohol consumption. Sleep apnea is a breathing related sleep disorder, characterized by heavy snoring and abnormal pauses in breathing. Moderate to large amounts of alcohol consumed in the evening can lead to a substantial narrowing of the airway, increasing the frequency and duration of breath holding episodes.

Tips for Sleeping Well Without Alcohol

Worried that sacrificing that glass of wine will lead to all nighters? Try out a few sleep tips below to kick the nightcap habit.

Sleep/wake consistency. Your sleep routine should be as consistent as your personal hygiene routine. Just like you brush your teeth and comb your hair in a certain order each morning, try to maintain a regular sleep/wake cycle by going to bed around the same time every night and waking up around the same time every morning (yes, even on weekends).
Get moving! Exercise is a good way to reduce stress. Exercising in the late afternoon or early evening raises your core body temperature above normal. Your temperature will start falling by bedtime and this natural decrease in body heat helps initiate the sleep process.
Let the light shine in the morning. While you probably know that light tells the brain it is time to wake up, it also helps set your internal sleep/wake clock. Try eating breakfast outside -- sunlight exposure for just 30 minutes in the morning should help you stay alert throughout the day.
Kick your caffeine habit. It's no secret that caffeine is a stimulant. Avoid coffee, soda and tea after 2 p.m. If you need a natural boost, sip on a glass of ice water.

If you are concerned about the impact alcohol has on your sleep, discontinue drinking within a few hours of bedtime. In general, it takes about an hour to metabolize one ounce of alcohol. If your sleep problems persist despite your best efforts, talk with your family physician.