Expert: Mark Bornfeld DDS - 10/16/2006

Question
Had a full set of exrays when I went to a new dental office  due to a change in my insurance coverage about 18 months ago. My next scheduled appointment for a cleaning includes taking more exrays. Would like to know what the general rule is regarding time between exrays when there are no problems. My last dentist I believe did them every 2 years and that was what I think is called bitewing.  Thank You

Answer
Dear Joanne,

There is no standardized, general consensus regarding the proper time interval between radiographic examination. The law affords the dentist broad discretion in judging when the additional information that would be conveyed by x-rays would sufficiently aid in diagnosis to justify their use.

Due to the large variability in dental disease activity from patient to patient, it makes sense to let the dentist judge the proper x-ray frequency, since it allows him to customize the interval to the patient's previously demonstrated need.

Of course, past history is not always useful in determining need, and patients can manifest sudden increases in their disease activity. That is why the dentist's intuitive judgement is not infallible, but it is the best way available to tailor the radiographic frequency to the patient.

The philosophical difficulty with designating an appropriate time interval is that it is impossible to predict in advance just what an x-ray will disclose, so it is not always possible to know whether routine screening x-rays will avert difficulties down the road. Your query regarding the appropriate time interval between x-rays "when there are no problems" reflects this common misapprehension. In fact, may dental problems are without symptoms, so one cannot rule out the possibility of problems without taking x-rays.

As a general "average", most patients do not need a full mouth intraoral x-ray series (comprised of 16 to 18 films) more frequently than once every three to five years, although certain types of therapy (notably periodontal treatment) may require more frequent repetitions. A set of bite wing films (usually four exposures) are most commonly taken at yearly intervals, although this may likewise be adjusted according to the patient's tooth decay susceptibility. Additional films may be taken at any time in order to shed additional light on questionable pathology that may arise as indicated by visual or symptomatic evidence.

In the United States, most dental insurers will provide a benefit for either a full mouth intraoral (18-film) series or a single panoramic film once every three years. Although this will usually be sufficient, the patient will occasionally require additional films that exceed this frequency limit provision.

Hope this helps...

Mark Bornfeld DDS
www.dentaltwins.com
Brooklyn, NY