Nov 142014

Short Answer: Maybe not

Long Answer: As dentists, one of our pet peeves is patients who refuse x-rays but then expect us to tell them why they have a painful tooth or if they have any other problems. Dentists are regularly challenged by patients who refuse x-rays because they don’t want to be exposed to them and they see little value in exchange for a higher risk of cancer. Some questionable dental advice forums even tell readers that a “skilled dentist” should be able to diagnose dental problems without x-rays at all. This is utter nonsense. The only way to detect cavities when they are small and between the teeth is with x-rays. A dentist who waits until a tooth hurts or a cavity is so large it can be seen without x-rays would be acting too late. By that point, far more expensive and complicated treatment would be necessary. Many of those treatments would require additional x-rays to complete and there would be an increased chance some of the affected teeth would be lost earlier in life. There is little disputing the enormous power of dental x-rays. As I tell my patients, upwards of 75% of my diagnosis comes from looking at them and only 25% comes from symptoms and a thorough clinical exam.

Fear of dental x-rays is a valid concern, for as everyone knows, x-rays can lead to cancer. But what most patients don’t realize is that the average dose needed for dental x-rays is very small compared to what they are envisioning. This is especially true when considering digital x-rays. Many are also not aware of how much radiation they are exposed to naturally 24 hours a day. There is radiation coming from outer space (cosmic radiation), from the ground and in the air we breathe. Radon gas, found at higher doses in some homes, is one of the leading causes of lung cancer, yet few people are very aware of it. Just a seven hour flight across the country exposes you to 0.03 mSv of radiation (Note: Dose of radiation is commonly measured in millisievert (mSv)). On average, when taking into account all this “natural” radiation, you and I are exposed to about 3.5 mSv per year.  If you went to the hospital and received a lower gastrointestinal tract x-ray, you would be exposed to a little over 4 mSv. By comparison, a set of four bitewing films in a dental office would expose you to 0.005 mSv, which is about HALF of a one-day-equivalent of “natural” background radiation. The amount is truly miniscule, so it’s important to keep things in perspective.

Nevertheless, we must not forget that all ionizing radiation is, indeed, harmful. Therefore, all x-rays should be kept to the bare minimum necessary. This is why I do object to cart blanc recommendations for annual or bi-annual x-rays when they are prescribed without regard for the patient’s specific situation. Unfortunately, most dentists pay no regard to the American Dental Association and Food and Drug Administration guidelines which recommend far fewer and less frequent x-rays than are usually prescribed. In their most recent guidelines, it was recommended to take four individual x-rays of back teeth (bitewing films) every two to three years, so long as the patient had no cavities and was not at an increased risk of developing them. For patients that have cavities and are susceptible to other dental problems, their recommendation is to take x-rays every six to eighteen months. Yet most dentists take updating x-rays on everyone every twelve months regardless of the circumstances. I believe this is largely a product of most dental insurance plans which pay for diagnostic x-rays once a year.

I have patients in my practice that are in their 30’s, they have never had a cavity, keep their mouth impeccably clean, use no medications and have no medical problems associated with increased dental problems (like diabetes or blood pressure medications). I believe it is unnecessary to prescribe annual x-rays for these patients, because the risk of radiation outweighs the extremely miniscule chance a dental problem will be discovered. The American Dental Association agrees with that perspective. For these patients I feel perfectly comfortable extending their x-ray frequency to every two or three years. Even average patients who have completed all their recommended dental treatment and have a track record of dental stability can easily extend their x-ray frequency to every 18 months. The patients I insist on seeing annual x-rays for are those with, among other things, previously diagnosed but untreated tooth decay, a history of recurring problems, many large/deep fillings, teeth that had root canals recently, changes in medications/medical situation, those with poor oral hygiene and those with active gum disease. When these patients insist on not having any x-rays, it puts me in a difficult situation. We as dentists are responsible for the patient’s oral health but want to honor their request. Some dentists have dealt with the problem by having affected patients sign a release form stating they don’t hold the dentist liable for not taking x-rays. This would likely not test well in court, because a medical provider cannot be released from practicing the Standard of Care (which is to take x-rays at least sometimes) by a patient. Nevertheless, the issue of x-rays remains a point of friction for many dentists and their patients.

As for children, my recommendation for frequency also falls in line with the American Dental Association recommendations. The frequency depends on whether or not the dentist can see between the teeth visually and whether the child has an increased risk or a history of cavities. In children, decay develops more quickly because baby teeth are softer and smaller than adult teeth. This makes it more important to catch cavities early.


If a dentist recommends annual x-rays and you are concerned, ask what it is about your specific dental situation that leads to the recommendation. If the answer is something like, “Because it is our policy to take x-rays on everyone every year.”, then this would be a legitimate reason for further inquiry. If, on the other hand, the answer is, “Because you have several teeth we think have cavities, we’re not sure your gum disease is under control and we are still working out the kinks in your home care routine.”, this would be far more reasonable and well-thought-out on the part of the dentist.

It is important to remember that if indicated, refusing x-rays will increase your risk of enduring more expensive and potentially painful problems later on. Like most medical problems, early detection of dental disease is easiest to treat. While reducing exposure to x-rays is a legitimate concern, it should also be a concern that undiagnosed dental disease will affect your health and the health of your mouth. The key is to question whether your prescribed frequency is customized for your specific situation or not.

Oct 302014

Short answer: At least 30 minutes and typically 45-60 minutes.

Long answer: During a routine cleaning, the dentist or hygienist needs to review any changes in your health, they need to evaluate the health of your teeth and gums and then counsel you on any improvements that should be focused on at home. Sometimes, the evaluation of your gums requires that they measure the gum pockets to look for signs of inflammation and bone loss. They then need to clean off any accumulations on your teeth, floss them and remove any stains. For most people, this takes a half hour at minimum and more likely longer. Some offices have special assistants that help the hygienist and this expedites the process. During a simple (routine) cleaning, only the surfaces above the gum (supracrestal) are cleaned. That’s why a simple cleaning is usually a comfortable procedure and doesn’t take much time to complete. Some people, in fact, have so little accumulation on their teeth that it is actually possible to do a thorough job in less than 30 minutes. But these are precisely the patients who are good candidates for less frequent cleanings. See, “Do I need a cleaning every six months?”. One other exception is patients with far fewer natural teeth than normal. If someone has half the normal set, then it would clearly take less time to clean them yet a decreased frequency may not be the best option. Also, it’s important to remember that a regular cleaning is very different than a “deep cleaning” and this is a topic that will be covered in an upcoming blog entry.

If you feel your cleaning is too short, inquire as to why that is. Consider asking for a less frequent cleaning if the answer is simply, “you don’t have much to clean.”. A thorough cleaning will remove the vast majority of stains and all hard tartar (calculus) on the surfaces of the teeth. In most people, this process takes more than 30 minutes to complete and usually 45 minutes or more.

Oct 162014

Short Answer: No

Long Answer: Most dentists will argue that a checkup every year is a wise thing to do and I would be hard pressed to disagree. But if a patient requested an exam every 18 months or even 24 months, I would not necessarily object so long as some criteria were met: they had a history of few or no cavities, they maintained good oral health and they did not start new prescription medications or have significant health changes. We are concerned with prescription medications because many of them cause xerostomia (dry mouth). A dry mouth doesn’t have the normal saliva flow which would otherwise buffer acids and wash away bacteria that cause decay. If a patient had some cavities every few years, had many teeth with fillings and other dental work or had a few health problems (this describes the majority of people) then an annual exam is appropriate. There has been some research looking for scientific evidence that frequent checkups by a dentist leads to fewer cavities. Recent reviews of these studies have shown that there is no specific recall frequency which is best for everyone. In fact, there is plenty of evidence to support the position that an exam frequency every 2 years does not result in a person having more cavities in the long run. And since dental decay takes anywhere from two to eight years to progress into an irreversible form, I can find little harm in waiting one to two years between dental exams. There are very rare situations when a person is at high risk of developing dental problems and they would need to be examined more frequently. But these situations are so rare that for the sake of answering the question, a checkup more frequently than once a year for the average person is not necessary.

[A Systematic Review of Dental Recall Intervals and Incidence of Dental Caries; The Journal of the American Dental Association May 2010 vol. 141 no. 5 527-539] [IS THERE A SCIENTIFIC BASIS FOR SIX-MONTHLY DENTAL EXAMINATIONS? The Lancet, Volume 310, Issue 8035, Pages 442 – 444, 27 August 1977 doi:10.1016/S0140-6736(77)90620-1 ]