Dental Scan or X-ray? What’s the Difference and Why Might You Need One?
While both are used in dentistry, a dental scan and an X-ray capture different information – and your dentist may recommend one, the other, or both depending on what they need to see. An intraoral optical scan records the visible surfaces of your teeth and creates a three-dimensional digital surface model. A dental X-ray provides different information and, depending on the type, can show areas between teeth, roots, supporting bone and other structures that are not represented in the same way by the surface scan.
In this article, “dental scan” means an intraoral optical scan. Intraoral scans and digital X-rays can both be used within digital dentistry, but they record different information.
You may also hear CBCT described as a 3D dental scan. CBCT uses X-rays, so it is different from the optical scan discussed here.
Dental Scan vs X-Ray: The Short Answer
Here’s a quick comparison of what each type of imaging can provide.
| At a Glance | Intraoral Scan | Dental X-Ray |
|---|---|---|
| What It Records | Visible tooth surfaces, and contours used to create a three-dimensional digital model | Information from areas and structures that a surface model cannot show in the same way, depending on the type of X-ray |
| Main Role | Creates a surface model that can support selected treatment planning or fitted dental work | Provides information about teeth and supporting structures when clinically indicated |
| Ionising Radiation | A standard intraoral optical scan does not use ionising radiation | Uses ionising radiation |
What Does an Intraoral Scan Show?
Intraoral scan records the surfaces of your teeth and builds them into a detailed digital model. This can show their shape and position, as well as how your upper and lower teeth meet when you bite.
Your dentist may use this type of model when:
- assessing tooth position for Invisalign treatment or clear aligners
- planning a retainer
- planning a crown or other fitted dental work.
Because this is a model of the tooth surfaces, it doesn’t show the roots or supporting bone in the way an X-ray can.
What Does a Dental X-Ray Show?
There are different types of dental X-rays, and the information they provide varies.
For example:
- Bitewing X-rays can show areas between the teeth and the surrounding bone level.
- Periapical X-rays can show an entire tooth, including its root and surrounding structures.
- Panoramic X-rays provide a broader view of the mouth and jaws.
The type used depends on what your dentist needs to see.
An X-ray does not replace the clinical examination, and it does not create the three-dimensional surface model used for selected treatment planning or fitted dental work in the way an intraoral scan does.
What Happens During a Scan or X-Ray?
For an intraoral scan, a dentist or dental professional moves a handheld scanning wand around your teeth. As the wand records the different surfaces, a digital model is built on screen.
How an X-ray is taken depends on the type of image needed. Some involve placing a small sensor inside your mouth. For a wider image, you may be positioned in a machine that moves around your head. You’ll generally need to keep still while the image is taken.
Parramatta Dental Avenue uses TRIOS 3 and TRIOS 5 intraoral scanners. Digital X-rays can also be taken onsite using low-dose technology when they’re considered necessary following a clinical assessment.
If you’re unsure why a particular image is being taken, ask your dentist what they’re looking for and how the image will help.
What About Radiation from Dental X-Rays?
Dental X-rays use ionising radiation. A standard intraoral optical scan does not.
The Australian Radiation Protection and Nuclear Safety Agency’s guidance on dental imaging states that radiation exposure from dental imaging is very low level and unlikely to have health effects.
“Digital” refers to how the X-ray image is captured and processed. It doesn’t mean the X-ray is radiation-free.
Your dentist considers whether an X-ray is appropriate based on the clinical reason for taking it and the information they need.
How Does Your Dentist Decide Which Imaging You Need?
Different clinical questions require different information. Your dentist considers the clinical examination, your symptoms, dental history, proposed treatment and any relevant previous images before deciding which imaging, if any, may be useful.
For clear aligner treatment, a digital model may help with planning, while radiographs may also be needed to assess the teeth and supporting structures when clinically indicated. For another concern, an X-ray may be used to examine a root, supporting bone, possible infection, tooth development or the wider jaw.
Not every patient or appointment needs both. You don’t need to work out which type of imaging you need before your appointment. If your dentist recommends a scan or X-ray, ask what they are looking for and why the image is useful.
If you have a dental concern you’d like assessed, book an appointment online with Parramatta Dental Avenue.
Frequently Asked Questions
Can a Dental Scan and an X-Ray Be Taken at the Same Appointment?
Yes, if both are useful for your assessment or planned treatment. They capture different types of information, so having one does not necessarily make the other unnecessary.
Will I Be Able to See My Dental Scan or X-Ray Straight Away?
An intraoral scan builds a digital model on screen as your teeth are scanned. Digital X-ray images can also be viewed electronically, allowing your dentist to talk you through what they show.
How Long Does a Dental Scan or X-Ray Take?
The time required depends on the type of scan or X-ray and the number of images needed. Your dental team can explain what to expect before the imaging begins.
Do Dental Scans or X-Rays Hurt?
Dental scans and X-rays are generally not painful, though some people may experience brief discomfort. An intraoral scan involves moving a handheld scanner around your teeth, while some dental X-rays require a small sensor to be placed inside your mouth. Wider X-rays may be taken with a machine positioned around your head. If anything feels uncomfortable, let your dental team know.