X-ray use in Dentistry

X-rays, also commonly known as radiographs, are a common part of dental treatment. However, many people have concerns about the safety of their use and whether they are really necessary.
Are X-rays safe?
The main concern for many people is whether exposure to the radiation used in dental x-rays is harmful. The amount of radiation you are exposed to during a single x-ray taken by your dentist is extremely small and is generally less than the background radiation (i.e. radiation from the atmosphere, sun and stars) to which you are exposed on any given day.
Your dentist will reduce any potential risks by limiting the number of x-rays taken; they will be taken only in circumstances where it is absolutely necessary for accurate assessment or diagnosis of dental conditions. Your dentist will also reduce your exposure to radiation through lower x-ray doses and targeted positioning of the x-ray machine.
Furthermore, continuing advances in medical technology ensure that radiation exposure from diagnostic x-rays is continually diminishing. For example, most dental practices have now embraced digital radiography, which reduces radiation exposure by up to 80%.
Additionally, although not strictly necessary for most patients, many practices continue to use a lead-lined apron which is laid across the patient during the x-ray. Similarly, in some instances practices may also continue to use a neck collar or thyroid protector particularly in the case of children or young adults.

Are X-rays necessary?
X-rays are a necessary part of a thorough dental examination. They provide your dentist with a high level of detail of the tooth, bone and supporting tissues of the mouth that are not evident by visual inspection with the naked eye.
X-rays can also help your dentist to detect potential problems, sometimes even before symptoms begin to appear. Conditions such as hidden cavities, cysts, infections, impacted teeth, oral cancers and bone loss due to gum disease are some of the conditions that may not be externally visible, but show up in a dental x-ray.
Additionally, X-rays are also often necessary prior to a number of procedures such as tooth extraction, fitting of crowns, bridges and braces and prior to a root canal treatment. Furthermore, x-rays would be necessary in the event of a traumatic injury to the teeth or jaw to help diagnose the full extent of any damage.
How often should teeth be x-rayed?
The answer to this, like most medical questions is "It depends". For patients with good oral hygiene who visit their dentist regularly and have no underlying issues of concern x-rays are generally only required every 12 to 36 months. However, depending on a patient's medical and dental history, and the current condition of the mouth, x-rays may be required at 6 monthly intervals.
Furthermore, there are some categories of patients where x-rays may be required at more frequent intervals. This includes:
Children & Teenagers - Children and teens who have a history of many cavities may need X-rays every six months or every year, depending on age. So may those who have a high risk of decay for other reasons. X-rays also help to keep track of tooth development.
Adults with crowns/bridges/implants - X-rays help the dentist find decay beneath your fillings and crowns or in new places
Patients with Periodontal (Gum) disease - X-rays can reveal signs of bone loss. If this has happened, then you may need periodontal (gum) surgery.
Patients with dry mouth (Xerostomia) - Saliva helps keep your mouth and teeth healthy by regulating the acid levels (pH) in the mouth. In a dry mouth, the pH decreases. This causes the minerals in the teeth to break down, resulting in more cavities.
Patients that smoke - Smoking increases the risk of bone loss around the teeth and periodontal disease.

X-rays and pregnancy
When visiting the dentist If you are pregnant or even if you just think you may be pregnant, then it is important to let your dentist know. X-rays during pregnancy pose an extremely low risk to your developing baby as the level of radiation used in dental x-rays is absolutely minimal and very specifically targeted to a small area.
Additionally, it is standard procedure to limit foetal exposure to x-rays through the use of a lead-lined apron which covers the mother (and the baby) from neck to knees.
If you are considering becoming pregnant then it is a great idea to have a comprehensive dental examination prior to becoming pregnant as this is the most practical way to avoid potential x-ray exposure during pregnancy.
However, it is important that you continue to attend your dentist on a regular basis when you are pregnant as the hormones released during pregnancy can make some women more susceptible to gum diseases such as gingivitis and other periodontal diseases which are likely to require treatment. Also, exposure to the teeth to strong stomach acids from reflux or vomitting due to morning sickness can cause damage to the tooth's protective enamel layer leading to an increased risk of decay.
If you have any concerns about any of the risks or benefits of receiving x-rays as part of your routine dental treatment then please talk to your dentist; we are more than happy to answer any questions you may have.