Dental X-ray types and safety

Dental X-rays detect problems that visual examination alone cannot find — approximately 60 percent of cavities are first identified on X-rays before becoming visible or causing symptoms. Modern digital X-rays use about 80 percent less radiation than older film systems. The American Dental Association recommends X-ray frequency based on individual clinical need, not a fixed schedule. Most adults at low cavity risk need bitewings every 18 to 24 months and a panoramic every 3 to 5 years.

Written by Dr. Husna Khan, DDS

Serenity Dental of Bloomingdale · August 27, 2026

Questions about your imaging schedule are welcome at any visit. Call (630) 359-0105 to review your X-ray history before your next appointment.

For the broader picture of preventive care, see the dental cleanings and exams service page. For details on what happens at a cleaning visit, see what happens during a dental cleaning.

Why X-rays at all

The most clinically important reason: many dental problems are invisible to visual examination. X-rays detect:

In our Bloomingdale office, routine bitewings regularly change treatment plans by catching cavities between molars while they are small. We see the radiation question often, and walking through the numbers next to everyday exposures answers it better than reassurance alone.

Each image type earns its place by answering a question the others cannot, which is why bitewings own cavity detection between teeth, periapicals own root and bone questions on a single tooth, panoramics map the whole jaw at once, and cone beam scans reserve their higher dose for surgical planning. Right tool, right question. Modern safeguards stack on top of each other rather than replacing one another, so digital sensors cut dose against film, rectangular collimation narrows the beam to the sensor, thyroid collars shield tissue outside the field, and selection criteria decide whether the image is taken at all.

• Cavities between teeth — hidden by adjacent teeth, the most common location for missed cavities
• Cavities under existing fillings or crowns — not visible without imaging
• Bone loss from periodontal disease — only seen on X-rays before becoming severe
• Abscesses at root tips — infections in the bone surrounding tooth roots
• Impacted teeth — particularly wisdom teeth that haven’t erupted
• Cysts and tumors in the jaw bone — usually painless until advanced
• Developing teeth in children — to monitor eruption and identify problems early
• Root fractures — vertical or horizontal cracks not visible externally
• Foreign objects — particularly in trauma cases

The American Dental Association estimates that approximately 60 percent of cavities are first detected on X-rays. Skipping X-rays does not prevent problems — it allows them to progress unidentified.

The four main types of dental X-rays

Dental practices use four primary types of X-ray, each with specific clinical applications.

Bitewing X-rays

The most common dental X-ray. Bitewings show the upper and lower back teeth in a single image, capturing the crown portions and the adjacent bone level.

How they’re taken: The patient bites down on a small plastic or paper tab that holds the film or sensor in position. The X-ray machine is positioned at the side of the face. Each bitewing takes about 5 seconds of exposure. A standard set includes 4 bitewings — one for each side of the back of the mouth, two molars and two premolars per image.

What they show:

• Cavities between back teeth
• Bone level around back teeth
• Existing fillings and crowns
• Recurrent decay around or under fillings

Frequency: Every 18 to 24 months for adults at low cavity risk; every 6 to 12 months for higher-risk patients per ADA guidelines.

Radiation dose: Approximately 0.005 millisieverts per bitewing — equivalent to about 1 day of natural background radiation.

Periapical X-rays

Periapical X-rays show the entire tooth from crown to root tip, including the surrounding bone. Used to investigate specific symptoms or specific teeth in detail.

How they’re taken: A small film or sensor is positioned alongside the tooth being imaged. The patient holds the film in place or uses a positioning device. Each periapical takes about 5 seconds of exposure.

What they show:

• Complete tooth from crown to root tip
• Root anatomy
• Periapical lesions (infections at root tips)
• Root fractures
• Bone level around the entire tooth
• Quality of root canal treatment if present

When taken:

• Investigating tooth pain in a specific area
• Evaluating a tooth for root canal treatment
• Following up after root canal treatment
• Investigating trauma to a specific tooth
• Pre-extraction planning

Frequency: As needed for specific clinical questions, not on routine schedule.

Panoramic X-rays

A single image capturing the entire upper and lower jaws, all teeth, sinuses, and temporomandibular joints. Useful for big-picture views.

How they’re taken: The patient stands or sits in the panoramic X-ray machine. A bite tab positions the head correctly. The X-ray tube and film/sensor rotate around the head over about 12 to 18 seconds. The patient must remain still during the rotation. No film is placed in the mouth.

What they show:

• All teeth in a single view
• Wisdom teeth position and development
• Jaw joint condition
• Sinus conditions affecting upper teeth
• Bone conditions in the jaw
• Impacted teeth and supernumerary teeth
• Large pathology (cysts, tumors)

When taken:

• Initial new patient comprehensive exam (often)
• Adolescent evaluation for wisdom teeth
• Pre-treatment planning for extractions, implants, orthodontics
• Investigation of jaw pain or TMJ symptoms
• Routine monitoring every 3 to 5 years

Limitation: Resolution is lower than bitewings — panoramic is not ideal for detecting small cavities. Bitewings remain the standard for cavity detection.

Radiation dose: Approximately 0.014 millisieverts — still very low but higher than a single bitewing.

Cone Beam Computed Tomography (CBCT)

CBCT is 3D imaging technology that captures detailed views of teeth, jaw bones, sinuses, and surrounding structures. Most often available in specialty practices; some general dental offices have CBCT.

How they’re taken: Similar to panoramic positioning. The CBCT machine rotates around the head capturing hundreds of 2D images that software combines into a 3D reconstruction. Total scan time is 10 to 40 seconds depending on the field of view.

What they show:

• Complete 3D anatomy of teeth and jaw
• Precise position of impacted teeth
• Sinus anatomy in detail
• Complex root canal anatomy
• Available bone for implant placement
• Pathology in three dimensions

When ordered:

• Dental implant treatment planning
• Complex impacted tooth evaluation
• Difficult root canal cases
• Severe trauma assessment
• Jaw pathology investigation

Radiation dose: Approximately 0.05 to 0.1 millisieverts — higher than 2D X-rays but significantly lower than medical CT scans of the head (which run 1 to 2 millisieverts).

Radiation safety in modern dentistry

Concerns about dental X-ray radiation are common and worth addressing with current science.

How much radiation is in a dental X-ray?

The radiation dose from dental X-rays is extremely small. For comparison:

A bitewing X-ray exposes you to approximately the same radiation as one day of natural background environmental exposure. A full-mouth X-ray series is equivalent to about 18 days of background exposure — still within ranges considered safe.

Why digital X-rays are safer than film

Digital X-ray sensors are far more sensitive than the film systems they replaced:

• Approximately 80 percent less radiation required to produce a diagnostic image
• Immediate image display — no need to retake if positioning was off (which would add radiation)
• Image enhancement through software allows diagnostic detail without repeat exposures
• No chemical processing required, eliminating disposal concerns
• Easy archiving and sharing between dental and medical providers

Most dental practices in the U.S. switched to digital systems between 2005 and 2015. If your practice still uses film, you are receiving more radiation than necessary.

Lead aprons and thyroid collars

Lead aprons drape over the chest and abdomen during X-ray exposure to block any scattered radiation. Thyroid collars protect the thyroid gland in the front of the neck. Both reduce the already-low exposure from dental X-rays even further.

Some recent guidelines from the American Academy of Oral and Maxillofacial Radiology have suggested lead aprons may not be necessary with modern digital X-ray systems and proper beam collimation. Practices vary in their protocols. If you prefer the apron and thyroid collar, request them.

Who needs more careful evaluation

While dental X-ray radiation is minimal for most patients, additional caution applies in some situations:

Pregnancy: Necessary X-rays are safe with shielding. Routine non-urgent X-rays may be deferred until after pregnancy. Discuss timing with the dentist.

Children: Use the same safety practices as adults, with attention to right-sized exposure parameters. Cumulative lifetime radiation from dental X-rays is low even for patients who have annual bitewings throughout childhood and adulthood.

Patients with thyroid concerns: Thyroid collars are particularly recommended. Some patients with prior thyroid radiation history have additional considerations — mention to the dentist.

Frequent travelers, radiation workers, or recent CT scans: Cumulative radiation exposure is higher. The dentist may extend X-ray intervals if clinically reasonable.

How dentists decide which X-rays you need

X-ray decisions follow the ALARA principle — “As Low As Reasonably Achievable” — balancing diagnostic need against radiation exposure. The American Dental Association publishes evidence-based guidelines for X-ray prescription based on individual clinical factors.

Factors increasing X-ray frequency:

• High cavity risk (recent cavities, dry mouth, frequent sugar intake)
• Periodontal disease history requiring monitoring
• Existing extensive restorations needing assessment
• Pediatric patients with developing teeth
• Specific symptoms requiring investigation
• New patient with no recent X-rays available
• Trauma history

Factors allowing extended intervals:

• Excellent oral hygiene with no recent cavities
• Stable periodontal status
• Adult patient with minimal restorations
• Recent X-rays from previous dental provider available

The dentist documents the rationale for X-ray decisions and discusses them with the patient. Patients can always ask why a specific X-ray is being recommended — a good dentist explains the clinical reasoning.

Concerns to discuss with your dentist

Patients sometimes have questions or hesitations about X-rays. Worth discussing:

“I had X-rays at my previous dentist 6 months ago.” Request that those X-rays be transferred. If diagnostic quality is adequate, new X-rays may not be needed.

“I’m pregnant or trying to become pregnant.” Tell the office before any X-rays. Routine X-rays may be deferred; necessary X-rays will use proper shielding.

“I had recent medical CT scans.” Mention this so the dentist can factor cumulative exposure into recommendations.

“I’m uncomfortable with X-rays in general.” A productive conversation with the dentist about clinical need versus your concerns helps both of you. Some delays are reasonable; complete refusal limits diagnostic accuracy.

“My insurance won’t cover X-rays this often.” Insurance frequency limits are not always the same as clinical recommendations. Discuss with the dentist whether the X-ray is clinically necessary now or can wait until covered.

“I’d like a written explanation.” Reasonable request — the dentist documents clinical reasoning for each X-ray order in your chart.

Schedule a comprehensive cleaning and exam at Serenity Dental by calling (630) 359-0105. Dr. Husna Khan recommends X-rays based on individual clinical need and ALARA principles, with proper shielding and modern digital sensors that minimize radiation exposure. Related: dental cleanings service page.

Personal imaging schedules are supposed to differ between patients, because a cavity-free adult with healthy gums can safely stretch bitewings to a two-year or even three-year rhythm while a patient with recent decay, deep pockets, or extensive restorative work genuinely benefits from a tighter interval. Schedules should differ.

A note on this article

This overview is general information about dental imaging. It does not replace an in-person exam or a conversation with your dentist about your specific imaging schedule. Frequency recommendations depend on your cavity history, gum health, and age.

Putting the dose numbers side by side is what finally settles most radiation worries, because four bitewings deliver about as much exposure as a short airline flight and a full panoramic image still sits far below the background radiation everyone absorbs from soil, air, and sky in an ordinary week. Context tames numbers. Skipping images to avoid dose can backfire in radiation terms alone, since a cavity that hides between molars until it needs a root canal will generate more films across diagnosis, treatment, and follow-up than a decade of routine bitewings would have used to catch it early. Avoidance has a dose. Pregnancy deserves its own sentence in any radiation discussion, and the professional consensus lands in a reassuring place, because necessary dental imaging with proper shielding is considered acceptable during pregnancy while elective full-mouth series simply wait a few months without any diagnostic penalty for the delay. Shielding settles it. Insurance rarely complicates imaging decisions the way it complicates crowns, given that preventive bitewings are typically covered at or near 100 percent on standard PPO plans, panoramic films are usually covered on a three-year to five-year cycle, and cone beam scans are the only category that routinely needs preauthorization.

When to call rather than wait

Questions about imaging schedules can wait for a routine visit. Some symptoms should not wait for the routine visit’s X-rays.

Call the same day for tooth pain with facial swelling. A periapical film at an urgent visit finds the abscess the same afternoon, and antibiotics plus drainage work far better early.

Call promptly for a dark spot you can see on your own tooth, pain when biting, or a tooth that has changed color. Each of these is an exam-plus-imaging situation where knowing when to call changes the outcome.

Call right away at (630) 359-0105 after any dental trauma, even if the tooth looks fine. Root fractures hide below the gumline and only imaging finds them before they fail.