In brief
Dental X-rays are recommended because many problems cannot be seen from the surface: decay between teeth, infection at root tips, bone loss from gum disease, problems under existing fillings and crowns, and the position of teeth that have not come in. X-rays are not taken on a fixed schedule for everyone. Your dentist recommends them based on your age, risk, symptoms and history, using the lowest exposure needed to get useful information.
Key takeaways
- X-rays reveal decay, infections and bone loss that visual exams cannot detect.
- Frequency is tailored to your risk, not a fixed universal schedule.
- Digital X-rays use very low radiation doses compared with everyday background exposure.
- New patients often need baseline images; transferring previous films can reduce retakes.
Dental X-rays are recommended because many dental problems cannot be seen during a visual exam. They show decay between teeth, infection at the tips of roots, bone loss from gum disease, problems hidden under fillings and crowns, and the position of teeth that have not come in yet. X-rays are not taken on a fixed schedule for everyone; your dentist recommends them based on your age, risk, symptoms, and history.
Many patients wonder why X-rays are needed when nothing hurts, or whether they are safe. These are fair questions. This guide explains what X-rays reveal, the common types, how often they are usually taken, what dentists do to keep exposure low, and what to ask if you have concerns.
Why do dentists take X-rays if nothing hurts?
Because many of the most treatable dental problems are painless in their early stages. By the time a cavity or infection hurts, it has often grown larger and may need more involved treatment.
X-rays help your dentist find problems while they are still small, such as:
- A cavity starting between two back teeth.
- Early bone changes from gum disease.
- An infection at the root tip of a tooth that feels fine.
- Decay creeping under the edge of an old filling.
Catching these early usually means simpler, less costly care. That is the main reason X-rays are part of a thorough dental exam.
What do dental X-rays show that a visual exam cannot?
Decay between teeth
The surfaces where neighbouring teeth touch are hard to see directly. Cavities often start here in adults and older children. Bitewing X-rays are designed to show these areas.
Problems under existing dental work
Decay can begin at the edges of fillings and crowns and spread underneath, where it cannot be seen until the restoration fails. X-rays can show these changes earlier.
Root and bone infections
An infection at the tip of a root, often a sign that the nerve inside the tooth is damaged or dying, shows up as a change in the bone on an X-ray. It may appear before any symptoms. This information helps your dentist decide between treatments, as explained in root canal vs dental filling, and is often part of confirming the signs you may need root canal treatment.
Bone levels and gum disease
X-rays show the height of the bone that supports your teeth. Bone loss is a key sign of gum disease, which often has no symptoms early on. Our article on the early signs of gum disease explains what else to watch for.
Tooth development and position
In children and teens, X-rays help track adult teeth as they develop and come in. In adults, they help assess wisdom teeth, teeth that have not come in, and the space available for treatment such as implants.
Other findings
X-rays may also show cysts, unusual growths, cracked roots, or changes in the jaw. Most of these findings are uncommon, but when they do occur, finding them early matters.
What are the common types of dental X-rays?
| Type | What it shows | When it is often used |
|---|---|---|
| Bitewing | The crowns of the upper and lower back teeth on one side | Checking for decay between teeth and bone levels at checkups |
| Periapical | One or a few whole teeth, from crown to root tip | Investigating pain, infection, or a specific tooth |
| Panoramic | The full upper and lower jaws, teeth, and nearby structures in one image | Overall assessment, wisdom teeth, and treatment planning |
| Three-dimensional (cone beam CT) | A 3D view of bone and teeth | Specific planning, such as some implant cases; not a routine image |
Your dentist chooses the type that answers the question at hand. Not every patient needs every type.
How often are dental X-rays taken?
There is no single schedule for everyone. The guiding principle is that an X-ray should be taken when the information it gives is likely to help your care. In practice:
- New patients without recent X-rays often have a set of baseline images at their first visit. This is part of the workup described in what happens during a new patient dental exam.
- Lower-risk adults with healthy teeth and gums may need checkup bitewings less often.
- People at higher risk, such as those with frequent cavities, gum disease, dry mouth, or a lot of dental work, may need them more often.
- Children may need X-rays at different intervals as their teeth grow and change.
- Specific problems, such as pain, swelling, a broken tooth, or an injury, may call for X-rays whenever they come up.
Your checkup schedule and your X-ray schedule often go together. Our article on how often you should visit the dentist explains why visit intervals vary.
Are dental X-rays safe?
Dental X-rays use a very low dose of radiation compared with many other medical imaging tests. Dentists follow the principle of keeping exposure as low as reasonably achievable. That means:
- Taking X-rays only when they are likely to help your care.
- Choosing the smallest number and type of images needed.
- Using well-maintained equipment and careful technique.
- Using protective measures where appropriate.
Digital X-rays generally use less radiation than older film systems. They also appear on screen right away, can be enlarged to see detail, and can be shared with another dental provider or your insurer when needed.
If you have questions about the dose from a particular image, ask your dental team. They can explain why an image is recommended and what it will show.
X-rays during pregnancy
Always tell your dental team if you are pregnant or may be pregnant. Routine X-rays may be postponed, while X-rays needed to diagnose pain, infection, or an urgent problem may still be recommended with appropriate precautions. Your dentist will discuss the options with you.
X-rays for children
Children can benefit from X-rays to find cavities between teeth and to monitor growing teeth. The number and frequency are based on each child’s needs and risk. If you have questions, ask at your child’s checkup; our article on what happens during a child’s dental checkup explains what that visit usually involves.
What happens when you have dental X-rays taken?
Having dental X-rays is quick and painless.
- You are seated comfortably in the dental chair.
- For bitewings or periapical images, a small sensor is placed in your mouth, and you gently bite to hold it in place.
- The X-ray unit is positioned near your cheek, and the image is taken in a moment.
- The process is repeated for each area needed.
- For a panoramic image, you stand or sit while the machine moves around your head for a few seconds.
If you have a strong gag reflex, a small mouth, or sensitive areas, let the team know. They can adjust the position or take a short break between images.
Can you refuse dental X-rays?
You can always ask questions and decline a specific X-ray. Your dental team will respect your decision. However, some problems simply cannot be diagnosed without imaging, such as decay between teeth, root infections, and bone loss. Declining all X-rays can limit what a dentist can safely diagnose and treat, and they may explain this and note your decision in your record.
If you have concerns, talk them through. Sometimes recent X-rays from another office can be used instead, or the timing can be adjusted based on your risk.
Can you use X-rays from your previous dentist?
Often, yes. If you are changing offices, ask to have your recent X-rays and records transferred. Recent images can reduce the need for retakes and give your new dentist a way to compare changes over time. Older images are still useful for comparison, even if new ones are needed.
How does a dentist read a dental X-ray?
On a dental X-ray, dense structures appear lighter and less dense areas appear darker. Enamel, metal fillings, and crowns look bright white. Healthy bone looks light grey with a fine pattern. Decay, which softens tooth structure, shows up as a darker shadow in the tooth. Infection at a root tip often appears as a dark area in the bone around it.
Your dentist compares what they see with your symptoms, your exam findings, and any older X-rays. A single image is rarely the whole story; comparing images over time is often what shows whether a small shadow is stable or growing. If you are curious, ask your dentist to point out what they are looking at. Seeing it for yourself can make a recommendation much easier to understand.
Do you still need X-rays if you have dentures or implants?
Often, yes, though usually less frequently than for natural teeth. For people with dentures, X-rays may be used to check the bone under the denture, look for roots or fragments left in the jaw, or investigate a sore spot that does not heal. For dental implants, X-rays help monitor the bone level around each implant over time, since bone loss around an implant can happen without symptoms. Your dentist will recommend imaging based on what you have and how things look at your exam.
What happens if an X-ray shows a problem?
Your dentist will explain what they see and what it may mean. Some findings, such as a very small area of early decay, may be watched and managed with better home care and fluoride rather than treated right away. Others, such as a cavity that has reached the inner layer of the tooth, usually need treatment. You will hear about the options, the alternatives, what happens if you wait, and the estimated fees before any decision is made.
Sometimes a finding needs another type of image or an opinion from another dental provider. If so, your dentist will explain why and what the next step involves.
Are dental X-rays covered by insurance?
Many dental insurance plans include some coverage for X-rays, often with limits on how often certain types are covered. Plans vary, so check your plan details or ask our team. At York Street Dental Centre, we offer direct billing to many insurance plans and welcome eligible Canadian Dental Care Plan (CDCP) patients. We explain what we recommend, and the estimated fees, before any treatment.
Questions to ask about your X-rays
If you would like to understand your imaging better, it is reasonable to ask:
- What is this X-ray looking for?
- How often do I need this type of image, based on my risk?
- Can you show me what you found?
- Can my previous X-rays be used instead?
- Are there any precautions because of pregnancy or a health condition?
Why are X-rays often taken for a toothache or dental injury?
When a tooth hurts or has been hit, the cause is not always where the pain seems to be. Pain can spread from one tooth to another, and a tooth can look normal on the outside while the root is cracked or infected. A targeted X-ray helps your dentist see the root, the bone around it, and any hidden fracture, so they can find the source of the problem and recommend the right treatment. After an injury, X-rays taken at the time can also be compared with later images to check how the tooth is healing.
When should you see a dentist about something X-rays might show?
Book an exam if:
- You are not sure when your last X-rays were taken.
- You have pain, sensitivity, or swelling around a tooth.
- A filling or crown feels rough, loose, or different.
- Your gums bleed or have receded.
- You have had an injury to your mouth.
- You are planning treatment such as an implant or wisdom tooth removal.
Contact the office promptly for facial swelling, severe pain, or a tooth that has been injured.
Dental X-rays and exams in Cornwall
At our family dental office at 118 York Street in Cornwall, we recommend X-rays based on your needs, not a one-size-fits-all schedule. We explain why each image is suggested, show you what we find, and talk through your options before any treatment.
Patients visit us from Cornwall neighbourhoods such as Glenview Heights, Eamer’s Corners, and the downtown area, and from nearby communities including Lakeview Heights and St. Andrews West. We are accepting new patients, and no referral is needed for routine care.
Book an exam
To book a checkup or ask about your X-rays, call York Street Dental Centre at (613) 932-1620 or request an appointment online. You can also learn more about digital X-rays at York Street Dental Centre.
Frequently asked questions
Are dental X-rays safe?
Dental imaging uses among the lowest radiation doses in medicine, further reduced by digital sensors, and is taken only when clinically justified. Discuss any specific concerns — including pregnancy — with your dental team.
Can I refuse X-rays and still be treated?
You can always discuss and decline specific images. But diagnosing decay between teeth, root infections and bone loss without imaging is often impossible, so declining all X-rays genuinely limits the care a dentist can responsibly provide.
Why do I need X-rays if nothing hurts?
Because the most treatable stages of decay, infection and bone loss are painless. X-rays are one of the main tools for catching problems while they are still small.
What is the difference between bitewings and a panoramic X-ray?
Bitewings are small detailed images of the crowns of back teeth, ideal for finding decay between teeth. A panoramic image captures the full jaws, joints and sinuses in one sweep — useful for overall assessment, wisdom teeth and treatment planning.
How often do I need dental X-rays?
It depends on your risk. New patients without recent X-rays often need baseline images. After that, adults with healthy teeth and gums may need checkup X-rays less often, while people with frequent cavities, gum disease, or a lot of dental work may need them more often. Pain, swelling, or an injury can call for X-rays at any time.
Can I have dental X-rays while pregnant?
Tell your dental team if you are or may be pregnant. Routine X-rays are often postponed, while X-rays needed to diagnose pain, infection, or another urgent problem may still be recommended with appropriate precautions. Your dentist will explain why an image is needed and discuss the options with you before taking it.
Sources
- Canadian Dental Association — X-Rays
- Cleveland Clinic — Dental X-Rays
- American Dental Association — Dental Radiographic Examinations
About the author
This article was written by the York Street Dental Centre Team and reviewed for clinical accuracy by the York Street Dental Centre dental team. York Street Dental Centre is a family dental office at 118 York Street, Cornwall, Ontario K6J 3Y8, providing general, preventive, restorative, and cosmetic dental care for patients of all ages.
Our articles explain common dental questions in plain language, cite reputable health and government sources where relevant, and are updated when guidance changes. Read our editorial policy or learn more about our practice.
This content is intended for general educational purposes and does not replace an examination, diagnosis or personalized treatment recommendation from a dental professional.