What are dental X-rays, and are they safe?

Many friends, family, and patients have asked me time and time again: What are dental X-rays used for, and do I need to take them?

In short, dental X-rays are part of a routine dental examination and check, and they help examine areas of the mouth that the naked eye does not see.

Dentists cannot diagnose their patient’s dental health definitively without dental X-rays.

This article will discuss questions such as: What are dental x-rays? What do dental x-rays show? What are the different types of dental x-rays?

Are dental x-rays safe for children? Are dental x-rays dangerous, and are there side effects?

Do dental x-rays cause cancer? Are dental x-rays safe during pregnancy?

How many dental x-rays are safe? What are the radiation doses for dental x-rays? How often do dental X-rays need to be taken?

WHAT ARE DENTAL X-RAYS?

Dental X-rays (also known as radiographs) show the inner structures of your teeth and the surrounding bone holding the teeth inside the mouth.

A sensor is placed inside the mouth, and the X-ray unit points to the sensor to take the dental X-ray.

They only need seconds, but the benefits are massive if we detect a problem early. It can save a lot of time, potentially cause pain and discomfort, and save a lot of money!

WHAT DO DENTAL X-RAYS SHOW? WHAT ARE THE BENEFITS OF DENTAL X-RAYS?

• They can reveal microscopic spots of deterioration between teeth that are not visible to the human eye.
• They can show the proximity of decay to the nerves of the teeth
• They can show the health or problems underneath old fillings, root canals, crowns or bridges, and implants
• They can show the presence and severity of gum disease, including tartar buildup and bone loss
• They can show dental abscesses or different types of dental infections
• They can show any developmental issues of teeth, such as deformed teeth, additional or missing teeth, and so on.
• They can show dental cysts and some types of tumours
• They can help to show problems such as tooth fractures and bone fractures
• They can show the proximity of tooth roots and infections to the sinuses
• They can show the development and number of teeth inside the mouth
• They can show the presence of wisdom teeth, and if there is a need for them to be removed
• They can show the amount of bone needed for dental implants

It is important to note that not all dental X-rays show the same information. It depends on the type of X-ray and why your dentist is taking it.

It’s also important to know that X-rays, like photos, are only snapshots of our mouths.

They will not tell us how long a tooth has been decayed, the infection has been present, or how quickly it will spread.

WHAT ARE THE DIFFERENT TYPES OF DENTAL X-RAYS?

The 3 main types of dental x-rays include:

• Bite Wing—These are routine dental X-rays that help examine the gaps between teeth to ensure no cavities or tooth decay underneath the tooth structure. They usually won’t show the whole tooth length because they aim to examine the gaps between teeth.
• Perapical (pA)—These are dental X-rays often taken to examine the whole length of the tooth to help identify signs of cracks, abscesses, infections, nerve problems, and bone defects. They are often taken in emergency appointments or when a tooth has chipped and needs a filling.
• Orthopantomography (OPG) – These are dental X-rays that look at the whole jaw. They show the entire anatomy of the upper and lower jaw bones. They assess the health of the bone surrounding the teeth. They are primarily used for patients with gum or periodontal disease. They often examine growing children and the potential for missing teeth. They can also help examine wisdom teeth and assess whether they need removal. They are used to look at broken teeth. They give a good summary of everything inside the mouth. However, you will often still need Bite-Wing or periapical X-rays to accompany OPGs and properly assess tooth decay or dental infections.

HOW OFTEN DO DENTAL X-RAYS NEED TO BE TAKEN?

Firstly, dental X-rays don’t always need to be taken whenever you see a dentist. According to the Australian Dental Association, it is recommended that your dental bite-wing x-rays are updated every 12-18 months if you’re a high-risk patient for tooth decay and every 2 -3 years if you’re a low-risk patient. Whether you’re a high-risk or low-risk patient depends on your oral hygiene, diet, lifestyle, medicines, and other factors.

Why do dental x-rays need to be taken? Even if you have regular six-month dental check-ups, we can never be 100% certain of what’s happening underneath the tooth structure until we see the dental X-rays. They are safe and take a few seconds, but dental X-rays help us avoid missing any problems that may be present but go unnoticed. 

Dental X-rays may also be taken when a toothache, dental abscess, or chipped tooth occurs during root canal treatment or when your dentist suspects a problem.

What do dental x-rays show? The dental X-rays will show the 3 main layers of the tooth:

Enamel: This is the outer white layer of the tooth on the X-ray. Dental fillings are typically sufficient to address any indications of deterioration in this layer.

Dentin is the middle light grey layer of the tooth on the X-ray. It makes up the majority of the tooth’s structure. Any signs of decay in this layer can be treated with a deeper filling, but the tooth may need root canal treatment if it is close to the nerve.

Pulp (nerve): Dark grey inner layer of the tooth. The black space is where the nerve and blood supply of the tooth lie. Any signs of decay in this layer are severe and will involve extractions or root canal treatment.

Are Dental X-Rays Safe? Understanding Risks, Side Effects, and Radiation Doses

Dental X-rays are entirely safe for both adults and children. While they involve radiation, the doses are very low and safe, equivalent to those you’d be exposed to simply from travelling on a 1-2 hour flight on a plane.

To put it in numbers, two bite-wing X-rays would emit 0.005mSv of radiation. Travelling from Sydney to Perth would expose you to 0.009mSv. An OPG emits 0.01 mSv.

So, you will get less radiation from your routine 2 Bite Wings and OPG than a return trip from Sydney to Perth. And you only take those Bite Wings and OPG x-rays once every 2 years.

This also means that dental X-rays are safe even for pregnant women if they are required to take them. What must be understood clearly is that radiation is everywhere around us.

Whether living in a brick house or being closer to the sun during a plane ride, we are all exposed to extra radiation.

But that doesn’t mean we should stop living in brick houses or that busy, frequent flyers should stop travelling. They don’t even think twice about the extra radiation they’re exposed to.

So why are we so afraid that dental X-rays are safe or dangerous? It’s all about education and understanding.

With time and technology, there are many ways to help reduce radiation exposure in dental X-rays. These include the following:

• Lower X-ray dose—The most crucial way to keep patients safe from radiation is for dentists to limit the dose emitted from the X-ray machine. This can be done by limiting the size of the cone beam on the machine to less than 7 centimetres in diameter. The X-ray machines are also reinforced, meaning there is little radiation exposure beyond the beam’s diameter.
• Improved film—The quality and speed of films and sensors used for dental X-rays have significantly improved. Improvements include requiring less dosage or radiation exposure to get the same results. Dentists who use the fastest-speed film (F-Speed) can limit the amount of radiation needed to obtain a clear X-ray picture.
• Digital radiography—Digital X-rays reduce radiation by as much as 80%. At Capstone Dental, we use digital X-rays for this reason. They also make treatment and diagnosis more efficient and comfortable for our patients.
• Film holders—Dental clinics used to ask dental patients to help hold the X-ray film inside their mouths with their fingers. This exposed the fingers to unnecessary radiation, but now, with film holders, we no longer need to do that.
• Regulatory Requirements—Our Australian state health departments require licences and routine maintenance checks for dental X-ray machines to ensure their safety and accuracy.
• Lead Aprons—Many dental clinics regularly place lead aprons over patients to help minimise radiation exposure. Still, nowadays, with modern technology and low dosages, the aprons offer more peace of mind than any statistically significant protection.
• Limit X-rays—Your dentist should only take X-rays when necessary to help make an accurate dental assessment or diagnosis. This is especially important when you come in with a chipped tooth or toothache, and we don’t know what is happening underneath the tooth structure and bone.

DO DENTAL X-RAYS CAUSE CANCER?

No. No conclusive evidence or research shows that dental X-rays cause cancer. Numerous studies claim an association between dental X-rays and cancer, but at best, no cause-and-effect has been proven regarding dental X-rays.

This is important to understand. For example, if a study on people who tripped over on the streets showed that a higher number of people who tripped over on the street also were cheese eaters, we can’t conclude that eating cheese causes people to trip over on the roads.

We can only say there is an association between street tripping and eating cheese. They’re VERY different statements. The Australian Dental Association published an article that helped explain the flaws and inconsistencies of one particular study regarding dental X-rays and cancer.

ARE DENTAL X-RAYS SAFE DURING PREGNANCY?

Yes, yes and Yes. Generally, there is far more risk to the foetus from poor diagnosis and inadequate treatment than taking a dental x-ray. Foetuses require their mothers to be healthy, as they depend completely on the maternal blood supply.

So their mothers need to be well-oxygenated, have an average temperature, have normal blood pressure, be well nourished, and be free of pain and anxiety.

The safe dose of radiation for foetuses is regarded as up to 5-10 millisieverts. Above this level, a detailed risk-benefit analysis, documentation, and documented patient consent are required.

At less than 1 millisievert from a dental x-ray, the risk to the foetus is minimal, and the consent process can be more routine. Dental radiation involves vastly lower foetal radiation doses than the upper limit of acceptable medical radiation exposure.

There is no detectable difference in cancer rates in children at radiation doses less than 5 millisieverts compared to background radiation. So, with the tiny doses involved in dental radiation, this issue does not need to be discussed further than the scientific evidence.

What is important to know is that untreated infection and pain are risky in pregnant women – they are vulnerable to sepsis (severe disease).

Sometimes, dental sepsis can be the source of this, so your dentist must do what they can to keep pregnant women safe and well from an oral health perspective.

Pain and infection increase the risk of adverse pregnancy outcomes, including miscarriage, intrauterine growth restriction, poor placental perfusion, and premature birth.

These risks far outweigh the radiation involved in diagnostic imaging from dental X-rays.

Dental X-rays in Seven Hills

Are you looking for a modern and gentle dentist who will care for you and your family?

Then, welcome to My Local Dentists Seven Hills. Our friendly team is ready to help you achieve optimal oral health.

Contact your Seven Hills dentist at (02) 8605 1696 or schedule an appointment online.

We are at Shop 55, (Ground Floor) Seven Hills Plaza, 224 Prospect Hwy, in Seven Hills.