Dental X-Rays Explained: Why Dentists Take Them

Why do dentists take X-rays?

Dentists take X-rays, or radiographs, to find problems not clearly visible during an examination, including decay between teeth, root-area changes, bone levels, developing teeth, and jaw findings. Health Canada says they support diagnosis and treatment planning.

Dental X-rays are not automatic at every visit. Health Canada and the Canadian Dental Association say imaging should follow a clinical examination and support diagnosis, safe treatment, or monitoring; routine screening without an examination is not recommended.

A dentist may suggest an X-ray when it could add information that changes assessment or care. Type and timing depend on your age, history, examination, symptoms, disease risk, and proposed treatment.

• X-rays show areas hidden between teeth or below the gums.
• They assess roots, supporting bone, jaws, and developing teeth.
• They can plan or monitor restorative, orthodontic, surgical, or implant care.
• No universal imaging schedule fits every patient.

What common dental X-rays can show

Different images answer different questions. Intra-oral X-rays use a detector inside the mouth; extra-oral X-rays use one outside the head, according to Health Canada.

Bitewings show the crowns of upper and lower back teeth, helping identify decay between them and assess supporting-bone level. Periapicals show a whole tooth, from crown to root, when the root area needs assessment.

A panoramic X-ray provides a broad two-dimensional view of the teeth and jaws, useful for developing or wisdom teeth, jaw structures, and some planning questions. CBCT produces a three-dimensional image for selected questions needing that detail. Health Canada classifies panoramic, cephalometric, and CBCT systems as extra-oral equipment.

• Bitewing X-rays show back-tooth crowns and spaces between them.
• Periapical X-rays show a whole tooth, root, and surrounding area.
• Panoramic X-rays provide a wide view of teeth and jaws.
• Cephalometric X-rays show the head’s side profile and jaw relationships.
• CBCT provides 3-D information for selected clinical questions.

When an X-ray may be suggested

A dentist may recommend imaging after reviewing your mouth, history, symptoms, and treatment needs. It may help assess suspected hidden decay, injury, root-canal or extraction planning, developing teeth, or the jaw.

X-rays can monitor a known concern or treatment progress, but a common image is not right for every person or appointment. The Canadian Dental Association says imaging needs a specific diagnostic or treatment-planning purpose, not routine periodic examination alone.

New patients may be asked about recent images from another office. Sharing records can reduce duplication, though new images may be needed when older ones cannot answer the current question or support comparison. Health Canada advises obtaining previous X-ray information rather than automatically retaking images.

For children and teens, imaging may relate to development, eruption, orthodontic planning, or disease risk. For adults, it may relate to findings, restorations, gum health, symptoms, or planned procedures. These examples are not a schedule.

• Bring dates and locations of recent dental images, if available.
• Tell the team about symptoms, prior treatment, and relevant medical information.
• Ask whether the image is for diagnosis, planning, or monitoring.
• Tell the team before imaging if you are or may be pregnant.

Are dental X-rays safe?

Health Canada says an individual dental X-ray delivers a low dose and generally presents a low risk of harm. Imaging should be justified and provide needed information at the lowest reasonable exposure.

Health Canada’s Safety Code 30 guides safe dental X-ray installation and use, including intra-oral, panoramic, cephalometric, and CBCT systems. It addresses equipment, facilities, quality control, and radiation protection.

The American Dental Association describes ALARA: justify exposures by benefit, keep necessary exposure as low as reasonably achievable, and maintain patient and staff doses well below allowable limits.

Tell your dentist if you are pregnant or may be pregnant. Health Canada says fetal exposure from dental X-rays is extremely low when the abdomen is not directly exposed, and the team can consider appropriate precautions.

Professional guidance does not treat lead aprons and thyroid collars as substitutes for justified imaging and proper technique. The ADA says they are not recommended for most dental imaging, including during pregnancy, because they are not the primary exposure control. Practices should follow applicable Canadian requirements and current guidance.

• Use imaging only when clinically justified.
• Modern equipment, positioning, quality control, and trained staff manage exposure.
• Tell the team about pregnancy, possible pregnancy, and previous imaging.
• Ask how the image answers a specific clinical question.

Questions to ask before a dental X-ray

You can participate without understanding every technical detail. The explanation should link the image to an oral-health question, and the ADA encourages informed discussion between dentists and patients.

Try these questions during an examination:

• Ask what the X-ray is looking for.
• Ask what examination finding makes imaging useful.
• Ask whether a previous X-ray answers the same question.
• Ask whether a smaller or different image would be sufficient.
• Ask how results could affect the next step.
• Ask whether the image is 2-D or CBCT and why that detail is needed.
• Ask when and how findings will be explained.
• Ask whether your plan requires an estimate and which costs to confirm before proceeding.

A simple decision framework for patients

Use this original four-part framework: Purpose, Existing information, Proportion, and Plan. It does not replace a dentist’s assessment, but can clarify the conversation.

Ask about Purpose: what question will the image answer? Review Existing information, including recent images, records, symptoms, and examination findings. Consider Proportion: does the image match the question, and why is wider or 3-D imaging needed? Confirm the Plan: how could results affect diagnosis, treatment, monitoring, or referral?

This framework avoids assuming every X-ray is unnecessary or every recommendation must be accepted without discussion. The goal is patient-specific imaging that adds useful information.

• P — Purpose means identifying the clinical question.
• E — Existing information means checking prior images and records.
• P — Proportion means matching image type to the question.
• P — Plan means understanding how results may affect care.

Common mistakes to avoid

Do not treat a fixed calendar interval as the only reason for imaging. The ADA says timing depends on oral health, age, disease risk, and signs or symptoms; no single interval fits everyone.

An X-ray alone does not provide the complete answer. The ADA says diagnosis and treatment planning should not rely on radiographs alone; images require interpretation with the examination and health history.

Practical details matter. Tell the team about pregnancy, share previous records, and ask how your plan handles diagnostic imaging. Confirm coverage with your insurer or dental office before treatment.

• Do not assume routine imaging is appropriate without an examination.
• Do not assume an older image is automatically suitable or unsuitable.
• Do not interpret an image without clinical assessment.
• Do not delay urgent dental guidance because you are unsure about imaging.
• Confirm coverage and direct billing under your plan.

What to do before your next appointment

Before visiting Countryside Dental Clinic, gather dates of prior X-rays, note concerns, and prepare imaging questions. If you need care in northeast Brampton, we can discuss examination needs and confirm services during booking.

Countryside Dental Clinic is part of a three-clinic group serving Brampton, Mississauga, and the greater GTA. We support CDCP, IFHP/refugee coverage, ODSP, and many private plans, with direct billing where permitted. Confirm coverage and service availability for your circumstances.

For preventive context, see How Dental Visits Fit Into a Family’s Preventive Care Routine. For coverage questions, see Dental Coverage in Brampton: Questions to Ask Before Treatment.

Before proceeding, you should be able to explain what the image is for and how its result could help. Ask for a plain-language explanation if needed.

• Bring previous imaging information when available.
• List symptoms, dental injuries, and recent treatment.
• Mention pregnancy or possible pregnancy.
• Ask about imaging purpose, type, timing, and possible coverage.
• Request an appointment with Countryside Dental Clinic for an oral-health assessment.

Key takeaways

• Dentists use X-rays to see structures and conditions not visible during an examination.
• Imaging should be patient-specific and clinically justified, not repeated automatically or for convenience.
• Different images assess concerns from decay between teeth to jaw and 3-D planning questions.
• Health Canada says an individual dental X-ray generally presents a low risk while emphasizing appropriate use and safety.
• Ask why the image is needed, whether prior images help, and how results may affect care.

Sources

1. X-rays: Medical and dental X-rays
2. Radiation Protection in Dentistry: Safety Code 30
3. Control of X-Radiation in Dentistry
4. X-Rays/Radiographs
5. New Radiography Recommendations

Questions about your dental health?

Request an appointment with Countryside Dental Clinic to discuss your oral health assessment and any proposed dental imaging.

Request an appointment