Dra. Cléo Salustiano In this article
SummaryTypes of dental X-rays and when each one is usedHow the exam is done, radiation and X-rays during pregnancyFAQRead nextDental X-Rays, Panoramic X-Rays and CBCT Scans: What Each One Is For
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Dental X-rays show decay between teeth, roots, bone, impacted teeth and infections that cannot be seen with the naked eye. A periapical X-ray details one or a few teeth, a bitewing reveals decay between teeth, a panoramic X-ray gives an overview of the mouth in one image, and a dental CBCT scan shows the bone in 3D to plan implants, wisdom teeth near the nerve and complex cases. The radiation dose is low, the exam is quick, and the dentist only orders it when it can change the decision. During pregnancy, routine exams can wait, but necessary ones can be done with protection. In Mooca, Dr. Cléo Salustiano (CRO-SP 170844) sees patients every day, from 8 a.m. to 10 p.m.
A dental X-ray is an imaging exam that shows what the dentist cannot see with the naked eye: decay between teeth, roots, bone, impacted teeth and infections. The most common types are the periapical X-ray (one or a few teeth, with root detail), the bitewing (decay between teeth), the panoramic X-ray (an overview of the whole mouth in a single image) and the dental CBCT scan, which is three-dimensional and reserved for planning and specific questions. The radiation dose of dental exams is low, and the dentist only orders an exam when it can change a treatment decision.
A frequent question at the office is whether a panoramic X-ray replaces the others. It does not: it is very useful for seeing the whole picture, but it shows less detail of each tooth. That is why the dentist often orders a panoramic image and then smaller X-rays of specific teeth, or recommends a CBCT scan when a 3D view is needed.
Dr. Cléo Salustiano (CRO-SP 170844), a dentist in Mooca, explains what each exam is for, how it is done, how to prepare, what changes during pregnancy and why not every patient needs all of them.
This article comes from Dr. Cléo Salustiano's dental office in Mooca, São Paulo (care in English, Portuguese and Spanish). See the general dentistry page to learn how the treatment is done here and book your assessment.
Types of dental X-rays and when each one is used
Periapical X-ray: the small X-ray of one or a few teeth, taken with a sensor or film placed inside the mouth. It shows the whole tooth, from the crown to the tip of the root, and the surrounding bone. It is the most used exam to assess pain, suspected root infection, follow a root canal and check deep fillings. The article when do you need a root canal shows how this exam fits into the diagnosis.
Bitewing X-ray: you bite on a small tab and the image shows the crowns of the upper and lower teeth at the same time. It is the exam that best reveals decay between teeth, where the mirror and probe do not always reach, as well as leaking fillings and the bone level between teeth.
Panoramic X-ray: the machine rotates around your head and produces a single image with all the teeth, the upper and lower jaw bones, the jaw joints and the sinuses. It is used for an overview at the first visit, to assess wisdom teeth and impacted teeth, plan orthodontics, follow tooth eruption in children and investigate bone lesions. Its limitation is detail: there can be overlap and distortion, and small cavities may be missed.
Dental CBCT scan: cone beam computed tomography produces three-dimensional images that show the bone in slices, allow measuring its height and thickness and locate structures such as the nerve in the lower jaw. It is ordered when a regular X-ray is not enough: dental implant planning, wisdom teeth very close to the nerve, root fractures, hard-to-find canals, cysts and lesions. The dose is generally higher than a regular X-ray, so it is not a routine exam.
| Exam | What it shows | When it is usually ordered |
|---|---|---|
| Periapical | One or a few teeth, from crown to root tip | Pain, suspected infection, root canal treatment |
| Bitewing | Crowns of upper and lower teeth | Decay between teeth and leaking fillings |
| Panoramic | All teeth, jaw bones, jaw joints and sinuses | Overview, wisdom teeth, orthodontics, impacted teeth |
| CBCT scan (cone beam) | Bone and teeth in 3D, in slices | Implants, wisdom teeth near the nerve, fractures, lesions |
How the exam is done, radiation and X-rays during pregnancy
In most cases, the dentist examines you and, when needed, requests the exam, which is done at a dental radiology center; these centers usually ask for the dentist's request. The exam is quick, the exposure lasts a few seconds, and it requires no fasting or contrast. Beforehand, you remove earrings, piercings, necklaces, glasses, hairpins and removable dentures, because metal shows up in the image and makes it harder to read. Results usually come in digital format, often with a report from a dental radiologist, and your dentist interprets them together with the clinical exam.
About radiation: dental X-rays use low doses, and the consensus among health organizations is that the benefit outweighs the risk when the exam is properly indicated. The principle is to use the lowest exposure that still gives the information needed. That is why there is no fixed interval for everyone: people with many cavities, gum disease or ongoing treatment may need exams more often than people with a healthy mouth. Bring previous X-rays to your appointment; they can avoid repeats.
Dental X-rays during pregnancy: always tell the dentist you are pregnant. Routine exams can be postponed until after delivery, but when there is pain, infection or a need for diagnosis, a dental X-ray can be taken, because the beam is aimed at the mouth and the dose is low. The protective measures required by regulations and indicated by the professional are used. Delaying treatment of an infection may carry more risk than the exam itself.
This content is for information only and does not replace an individual assessment. Consult a dentist to find out whether you need an imaging exam and which one. In Mooca, Dr. Cléo Salustiano sees patients every day, from 8 a.m. to 10 p.m., including Sundays and holidays, for general dentistry and dental implant planning, requesting imaging exams when they are needed.
What is the difference between a panoramic and a periapical X-ray?
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A panoramic X-ray shows the whole mouth in a single image and is used for an overview. A periapical X-ray shows one or a few teeth in much more detail, including the root tip. That is why the two often complement each other.
What is a panoramic dental X-ray used for?
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It is used to assess the whole picture: the position of wisdom teeth, impacted teeth, bone loss, jaw lesions, orthodontic planning and tooth eruption in children. It does not replace smaller X-rays for small cavities and root details.
When is a dental CBCT scan needed?
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When a three-dimensional view is needed: implant planning, wisdom teeth very close to the nerve, suspected root fracture, hard-to-find canals, cysts and other lesions. It is not a routine exam, because the dose is higher than a regular X-ray.
Are dental X-rays harmful?
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Dental X-rays use low doses, and the benefit outweighs the risk when there is a clear reason for the exam. Dentists try to order only what is necessary and to use recent exams. Let your dentist know if you had X-rays taken elsewhere.
Can I have a dental X-ray while pregnant?
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Routine exams are usually postponed until after delivery. When there is pain, infection or a need for diagnosis, a dental X-ray can be taken with the protections required by regulations. Always tell the dentist you are pregnant.
Do I need to prepare for a panoramic X-ray?
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No fasting or contrast is needed. Just remove earrings, piercings, necklaces, glasses, hairpins and removable dentures before the exam. The machine rotates around your head for a few seconds, and it is important to stay still with your bite in the indicated position.
Where can I have a dental assessment with X-rays in Mooca?
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In Mooca, Dr. Cléo Salustiano (CRO-SP 170844) sees patients at Rua Hipódromo, 1141, near Bresser-Mooca station, Monday to Sunday, from 8 a.m. to 10 p.m., including holidays. She examines you and, when needed, requests the imaging exam. Appointments via WhatsApp (11) 97409-7834, in Portuguese, English or Spanish.
