Benefits of Dental X-Rays
Thursday December 1, 2005

Dear Dr. Mady: The first time I went to my dentist for an examination, five years ago, he had x-rays taken of all of my teeth. I go now about every six months for cleanings and check-ups and he has the hygienist take a couple of x-rays about every second visit. Sometimes they find cavities and other times they do not. What are the benefits of dental x-rays, how do they work and how often should they be taken?-Heather from Naples, Florida via e-mail

Dear Heather: Every time you go to visit your dentist and he looks in your mouth, many diseases that may exist in the teeth and in the tissues around them cannot be seen. However a dental x-ray is an excellent aid with respect to diagnosis of any anomalies or of good oral health.

Individuals who do not floss often get cavities in between their teeth just below where the teeth contact each other. A visual exam often is not sufficient to correctly diagnose these interproximal cavities, along with recurrent decay that may be growing underneath existing restorations that you have. Failing to diagnose these may ultimately lead to the need for root canal treatment or even extraction.

Also infections, abscesses or cysts in the jaw bone surrounding teeth can be easily seen on dental radiographs. These often exist for various reasons and you may not even be aware of them. There may also be other dental abnormalities existing that can not be visualized with the naked eye.

Gum disease or periodontal disease ultimately destroys the supporting structures of your teeth, including bone. Loss of this bone and the extent in all areas can easily be seen with x-rays and gives your dentist a better idea of which direction to go in as far as your dental treatment plan goes.

Basically the way that dental x-rays work is that a small amount of radiation passes through a selected area of your mouth and conveys an image of this area on a small dental film (intra-oral). There are larger films that are used to take an x-ray of a larger area and these films are used outside of the mouth (exta-oral). Examples of these are the panorex and the cephelogram.

In the process, more of the rays are absorbed by the denser tissues like teeth and bone than by the gums and cheeks, before these rays reach and hit the film. This is how the image is created. The reason that the teeth seem lighter is because fewer rays penetrate (are not absorbed as much). Infections, bone changes, ligaments that surround teeth and cavities appear darker on the x-ray because more rays penetrate these less dense areas. Existing fillings will show lighter or darker depending on the dental restorative material that was used in their placement.

Frequency of x-ray taking on dental patients is situation-specific. In simple terms, this means that it depends on the oral health needs of each individual patient. Every patient is different and the need for radiographs will be different and individualized for each. Your dentist will decide whether they are warranted and when, based on present signs and symptoms oral conditions, previous history of decay, age and risk of dental disease.

If it is your first visit and complete exam, your dentist usually will want more x-rays so that everything can be completely examined at that starting point. If there is no disease present or a possible problem starting, these radiographs can later be used as a vehicle to compare future changes with past conditions. If you have recently had x-rays taken at another dental office, forwarding these to your dentist or new dentist is a common practice. On the other hand if a referral to a dental specialist is later required for you, your dentist can simply send the radiographs there and omit the need for new ones to be taken.

Children may require dental x-rays more often than adults because their teeth and jaws are constantly developing and they are more likely to be affected by tooth decay than adults. Also the tracking of exiting baby teeth and entering permanent teeth is important. If you are an individual that has new cavities diagnosed every time you visit your dentist, x-rays will be taken more often so nothing gets missed.

Finding and treating dental problems at an early stage can save money, time, pain and unnecessary aggravation later on. They can detect damage to structures that are not evident during a visual oral exam and ones that exist but are asymptomatic. If you have a hidden tumor, dental x-rays may even help save your life!


This column is reprinted with the permission of the author and The Windsor Star. "Ask the Dentist" is written by Windsor dentist (and ECDS member), Dr. David Mady Jr.. The column appears the first Thursday of each month in the Windsor Star. Readers with questions can write to "Ask The Dentist", c/o The Windsor Star, 167 Ferry St., Windsor Ontario, N9A 4M5



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