Dental X-Ray: Types, Safety and What to Expect

What Is a Dental X-Ray?

A dental X-ray (dental radiograph) is a diagnostic imaging technique that uses controlled amounts of ionizing radiation to create images of teeth, roots, jawbone, and surrounding structures. These images reveal problems invisible during a visual examination, such as cavities between teeth, bone loss from gum disease, and infections at tooth roots.

Dental X-rays have been a cornerstone of dental diagnosis for over a century, revolutionizing the ability of dental professionals to detect and treat oral health problems before they become serious. The technology has evolved dramatically, with modern digital X-rays providing clearer images while using a fraction of the radiation required by traditional film-based systems.

During a dental X-ray, a small sensor or film is placed inside your mouth against the teeth being examined. An X-ray machine positioned outside your cheek directs a controlled beam of radiation through your teeth. Dense structures like tooth enamel and metal fillings absorb more X-rays and appear white or light gray on the image, while less dense structures like cavities, gum tissue, and bone loss appear darker.

The importance of dental X-rays in modern dentistry cannot be overstated. According to the American Dental Association (ADA), up to 60% of tooth surface area is hidden between teeth and cannot be examined visually. X-rays are the only reliable way to detect problems in these hidden areas before they cause pain, infection, or tooth loss.

Dental X-rays are typically part of a comprehensive dental examination, but they may also be taken separately when investigating specific symptoms or monitoring ongoing treatment. Your dentist will determine how often you need X-rays based on your individual oral health needs, age, risk factors, and any symptoms you may be experiencing.

Why are dental X-rays important?

Visual examination alone can only reveal surface-level problems on visible tooth surfaces. Many of the most serious dental conditions develop in areas that are impossible to see without radiographic imaging. Early detection through X-rays can mean the difference between a simple filling and a root canal, or between saving a tooth and losing it entirely.

Regular dental X-rays allow your dentist to establish a baseline of your oral health and track changes over time. This longitudinal monitoring is crucial for catching slow-developing conditions like periodontal bone loss, which may progress for years without causing noticeable symptoms until significant damage has occurred.

What Are the Different Types of Dental X-Rays?

The main types of dental X-rays are intraoral (taken inside the mouth) and extraoral (taken outside the mouth). Intraoral types include bitewing X-rays for detecting cavities between teeth, periapical X-rays for viewing entire teeth including roots, and occlusal X-rays for larger sections of the upper or lower jaw. Extraoral types include panoramic X-rays for a complete view of all teeth and jaws.

Different types of dental X-rays serve different diagnostic purposes, and your dentist will select the appropriate type based on what information is needed. Understanding the various types can help you know what to expect during your dental appointment and why certain images are being taken.

Intraoral X-rays (inside the mouth)

Intraoral X-rays are the most common type of dental radiograph. The sensor or film is placed inside your mouth to capture detailed images of individual teeth or small groups of teeth. These provide the highest level of detail and are essential for detecting cavities, evaluating root health, and assessing bone levels around teeth.

Bitewing X-rays are named for the way patients bite down on a wing-shaped holder to keep the sensor in place. These images show the upper and lower back teeth (premolars and molars) in a single image, capturing the crowns and the bone level between teeth. Bitewings are the standard X-ray for detecting cavities between teeth – the most common location for decay in adults. Most adults need bitewing X-rays every 1-2 years.

Periapical X-rays show the entire tooth from crown to root tip, including the surrounding bone. These are essential when investigating tooth pain, abscesses, or other problems affecting the root or surrounding bone. Unlike bitewings that focus on the crown area, periapical images reveal the full extent of any infection or pathology at the root apex.

Occlusal X-rays use a larger sensor placed on the biting surface of the teeth to capture a broader view of the upper or lower arch. These images are useful for detecting extra teeth, teeth that haven't erupted, jaw fractures, cleft palate abnormalities, cysts, and tumors. They show more of the dental arch than periapical images but with less detail of individual teeth.

Extraoral X-rays (outside the mouth)

Extraoral X-rays are taken with the sensor or film outside the mouth. While they provide less detail of individual teeth than intraoral images, they excel at showing the overall structure of the jaws, skull, and temporomandibular joints (TMJ). These images are essential for orthodontic treatment planning, oral surgery, and evaluating jaw disorders.

Panoramic X-rays (OPG – orthopantomogram) capture the entire mouth in a single image, including all teeth, upper and lower jaws, sinuses, and temporomandibular joints. The X-ray machine rotates around your head while you stand or sit still. Panoramic images are valuable for assessing wisdom teeth, planning implants, evaluating jaw tumors or cysts, and providing an overall view of dental health. However, they don't show the fine detail needed to detect small cavities.

Cephalometric X-rays show the entire side view of the head and are primarily used by orthodontists to assess the relationship between teeth, jaws, and facial profile. These images help plan orthodontic treatment and monitor growth in children and adolescents.

Cone beam computed tomography (CBCT) provides three-dimensional images of teeth, bone, nerve pathways, and soft tissues. While technically a form of CT scan rather than traditional X-ray, CBCT is increasingly used in dentistry for complex cases including implant planning, root canal treatment of complicated anatomy, and surgical planning. CBCT uses more radiation than conventional dental X-rays but far less than medical CT scans.

Why Would I Need a Dental X-Ray?

Dental X-rays are needed to detect problems invisible during visual examination, including cavities between teeth or under fillings, bone loss from gum disease, infections at tooth roots, impacted teeth, cysts, tumors, and developmental abnormalities. They are also essential for planning orthodontic treatment, dental implants, and oral surgery.

Your dentist may recommend dental X-rays for various reasons, ranging from routine preventive screening to investigating specific symptoms. Understanding why X-rays are necessary can help you appreciate their value in maintaining your oral health and make informed decisions about your dental care.

During routine dental checkups, X-rays serve as a crucial diagnostic tool that complements the visual examination. Even the most thorough visual inspection cannot reveal what's happening inside teeth, between tight contacts, or within the bone beneath the gum line. Regular X-rays establish a baseline of your oral health and enable early detection of developing problems.

Conditions detected by dental X-rays

Interproximal cavities (cavities between teeth) are among the most common findings on dental X-rays. These cavities develop in the contact areas between teeth where toothbrush bristles cannot reach and are often impossible to see clinically until they become quite large. X-rays can detect these cavities when they're small and easily treatable with simple fillings.

Decay under existing fillings is another common finding. Over time, margins of fillings can break down, allowing bacteria to seep underneath and cause new decay. This secondary decay can progress significantly before causing symptoms, making X-ray detection essential for timely treatment.

Periodontal bone loss from gum disease can be subtle and gradual. X-rays reveal the level of bone supporting each tooth, allowing your dentist to diagnose and monitor periodontal disease. Without X-rays, significant bone loss might go undetected until teeth become loose.

Periapical infections (abscesses) appear as dark areas at the tip of tooth roots on X-rays. These infections may develop from untreated cavities, cracked teeth, or failed root canals. Some abscesses cause severe pain while others remain asymptomatic despite causing significant damage.

Impacted teeth, especially wisdom teeth, are commonly evaluated with X-rays. Panoramic images show the position, angulation, and relationship of impacted teeth to adjacent structures, helping dentists determine whether extraction is necessary and plan the surgical approach.

Developmental abnormalities including missing teeth, extra teeth, and teeth developing in abnormal positions are readily visible on X-rays. Early detection allows for proper planning of orthodontic or surgical intervention.

Cysts, tumors, and other pathology of the jaws may be discovered incidentally on routine X-rays or when investigating specific symptoms. Early detection of these conditions can be life-saving in the case of malignancies.

When are dental X-rays particularly important?

• New patient examinations: Establishing a baseline of your oral health
• Investigating dental pain: Finding the cause of toothache or sensitivity
• Before dental procedures: Planning root canals, extractions, implants, or orthodontics
• Monitoring gum disease: Tracking bone levels in patients with periodontal disease
• Following up after treatment: Confirming successful completion of root canals or other procedures
• Children's dental development: Monitoring tooth development and detecting problems early

How Does a Dental X-Ray Procedure Work?

During a dental X-ray, a small sensor is placed inside your mouth against the teeth being examined. You bite gently to hold it in place. A lead apron protects your body. The X-ray machine is positioned outside your cheek and the image is captured in seconds. With digital X-rays, images appear on screen immediately. The entire process takes just a few minutes.

Understanding what happens during a dental X-ray can help reduce any anxiety you might feel about the procedure. The process is straightforward, quick, and designed with patient comfort and safety in mind. Modern dental practices have refined the procedure to be as efficient and comfortable as possible.

Preparation

Before your dental X-rays, you may be asked to remove any jewelry, eyeglasses, or removable dental appliances that might interfere with the images. There's no other special preparation required – you don't need to fast or take any medications beforehand.

A lead apron will be placed over your torso to protect your body from any scattered radiation. Many practices also use a thyroid collar to protect your thyroid gland, though this is particularly important for children and women of childbearing age. While the amount of scattered radiation from dental X-rays is minimal, these protective measures reflect the ALARA principle (As Low As Reasonably Achievable) that guides radiation protection.

The imaging process

For intraoral X-rays, the dental professional will place a small rectangular sensor inside your mouth, positioned against the teeth being imaged. The sensor is attached to a wire connected to the computer. You'll be asked to gently bite down on a holder that keeps the sensor in the correct position.

Once the sensor is positioned, the X-ray machine head is aimed at your cheek from outside your mouth. The dental professional will step behind a protective barrier or leave the room momentarily – this is standard practice since they work with X-rays many times daily and need to minimize their cumulative exposure.

You'll be asked to remain completely still for a few seconds while the image is captured. You may hear a beep or click when the X-ray is taken. With digital sensors, the image appears on the computer screen within seconds. If film is used (increasingly rare), it requires several minutes for developing.

Multiple images may be taken to capture different areas or angles. A complete series of bitewings typically includes four images (two on each side), while a full-mouth series may include 18-20 individual images.

What about discomfort?

The X-ray itself causes no sensation whatsoever – you won't feel any radiation. However, some patients find the sensor uncomfortable, particularly those with a strong gag reflex, small mouths, or sensitive gums. If you experience discomfort, let your dental professional know; they can often adjust the positioning or use smaller sensors to improve comfort.

For patients who struggle with intraoral X-rays due to gag reflex or other issues, extraoral options like panoramic X-rays may be used instead, though these provide less detail of individual teeth.

Are Dental X-Rays Safe?

Yes, dental X-rays are very safe. The radiation dose from a single dental X-ray is extremely low – about 0.005 mSv for a bitewing, which is less than one day of natural background radiation. Modern digital X-rays use up to 90% less radiation than traditional film. Lead aprons provide additional protection. The diagnostic benefits far outweigh the minimal risks.

Concerns about radiation exposure are understandable, but it's important to put dental X-ray radiation into perspective. The doses involved are extremely small, and the diagnostic benefits of detecting and treating dental problems early far outweigh any theoretical risks from the minimal radiation exposure.

Understanding radiation doses

Radiation exposure is measured in millisieverts (mSv). To understand how small dental X-ray doses are, consider these comparisons:

• Single bitewing X-ray: 0.005 mSv
• Full-mouth series (18-20 images): 0.15 mSv
• Panoramic X-ray: 0.01-0.02 mSv
• One day of natural background radiation: 0.008 mSv
• Cross-country airplane flight: 0.03-0.05 mSv
• Chest X-ray: 0.1 mSv
• Medical CT scan of abdomen: 10 mSv
• Annual natural background radiation: 3 mSv

As you can see, a dental bitewing X-ray delivers less radiation than you receive naturally in a single day just from cosmic rays and naturally occurring radioactive materials in the environment. Even a full-mouth series of X-rays represents a tiny fraction of annual background radiation exposure.

Digital X-rays and radiation reduction

The transition from film to digital X-rays has been one of the most significant advances in dental radiation safety. Digital sensors are far more sensitive than film, requiring up to 90% less radiation to produce a high-quality image. Most modern dental practices now use digital radiography exclusively.

Beyond lower radiation, digital X-rays offer additional advantages: images are available instantly, can be enhanced and magnified for better diagnosis, are easily stored and shared electronically, and eliminate the environmental concerns associated with chemical film processing.

Protective measures

Even though dental X-ray doses are minimal, dental practices follow the ALARA principle – keeping radiation As Low As Reasonably Achievable. Standard protective measures include:

• Lead aprons: Block scattered radiation from reaching the body
• Thyroid collars: Protect the radiation-sensitive thyroid gland
• Proper positioning: Ensures the X-ray beam is directed only at the teeth being imaged
• Rectangular collimation: Limits the X-ray beam to the size of the sensor, reducing unnecessary exposure
• Fast sensors: Require minimal radiation to produce an image

Cumulative exposure considerations

While individual X-ray doses are extremely low, some patients worry about cumulative exposure over many years of dental care. Research has shown that even frequent dental X-rays over a lifetime represent a negligible addition to total radiation exposure. The American Dental Association states that dental X-rays account for approximately 2.5% of the average person's annual radiation exposure from medical and dental sources combined.

Dentists take cumulative exposure into account when recommending X-rays. They balance the diagnostic necessity against radiation principles, prescribing X-rays based on individual patient needs rather than arbitrary schedules.

Can I Have Dental X-Rays During Pregnancy?

Yes, dental X-rays can be safely performed during pregnancy when medically necessary. The radiation dose is extremely low and the X-ray beam is directed away from the abdomen. A lead apron with thyroid collar provides additional protection for the developing baby. Emergency or necessary dental X-rays should never be postponed due to pregnancy, as untreated dental infections pose greater risks.

Pregnancy often raises concerns about any medical procedure involving radiation, and dental X-rays are no exception. However, major health organizations including the American College of Obstetricians and Gynecologists, the American Dental Association, and the American Academy of Pediatrics agree that dental X-rays are safe during pregnancy when necessary.

The developing fetus is not in the direct path of the dental X-ray beam, which is focused on the teeth and jaws. The extremely low radiation dose (equivalent to less than one day of natural background radiation) combined with protective lead shielding means that fetal exposure is negligible.

Why dental care during pregnancy matters

Pregnancy itself increases the risk of dental problems due to hormonal changes that can worsen gum disease, increased acid exposure from morning sickness, and changes in eating patterns. Untreated dental infections during pregnancy have been linked to adverse pregnancy outcomes including preterm birth and low birth weight.

Avoiding necessary dental treatment due to unfounded concerns about X-ray safety can actually pose greater risks to both mother and baby than the minimal radiation exposure. The American College of Obstetricians and Gynecologists specifically recommends that pregnant women receive necessary dental treatment, including X-rays when indicated.

Recommendations for pregnant patients

• Don't postpone emergency dental care: Infections and severe dental problems should be treated promptly
• Elective X-rays may be deferred: Routine screening X-rays without symptoms can often wait until after delivery
• Always use lead apron protection: This provides peace of mind and follows best practices
• Inform your dentist about your pregnancy: They can tailor care and discuss any concerns
• Continue routine dental cleanings: Maintaining oral hygiene is especially important during pregnancy

Are Dental X-Rays Safe for Children?

Yes, dental X-rays are safe for children and play an important role in monitoring dental development, detecting cavities, and planning orthodontic treatment. Children may need X-rays more frequently than adults because their teeth and jaws are still developing. Pediatric dentists use the lowest possible radiation doses and child-sized sensors for maximum comfort and safety.

Children's dental X-rays are an essential part of pediatric dental care, allowing dentists to monitor developing teeth, detect cavities early, and identify potential problems before they become serious. While parents naturally want to minimize their children's exposure to radiation, the benefits of appropriate dental X-rays outweigh the minimal risks.

Children may actually need X-rays more frequently than adults for several reasons. Primary (baby) teeth have thinner enamel and are more susceptible to rapid decay. Permanent teeth are developing beneath the gum line and may need monitoring for proper eruption. Childhood and adolescence are critical periods for detecting orthodontic issues that are easier to treat early.

Pediatric radiation safety

Pediatric dentists and dental radiologists are trained to minimize radiation exposure in children while obtaining the diagnostic information needed. Measures include:

• Using the lowest necessary dose: Modern equipment allows precise radiation control
• Child-sized sensors: Smaller sensors are more comfortable and require less radiation
• Thyroid collars: Children's thyroid glands are more sensitive to radiation
• Lead aprons: Protect the body from scattered radiation
• Digital radiography: Reduces radiation by up to 90% compared to film
• Selective imaging: X-rays are prescribed based on individual need, not routine schedules

The American Academy of Pediatric Dentistry recommends that dental X-rays be prescribed based on individual patient assessment rather than arbitrary age-based schedules. Factors considered include cavity risk, developmental concerns, and symptoms requiring investigation.

How Often Should I Have Dental X-Rays?

The frequency of dental X-rays depends on your individual oral health needs. Adults with good oral health and low cavity risk typically need bitewing X-rays every 1-2 years. Those with higher risk factors may need X-rays more frequently. Children and adolescents may need X-rays every 6-12 months due to rapidly changing dental development. Your dentist will recommend a schedule based on your specific situation.

There is no one-size-fits-all answer to how often dental X-rays should be taken. The appropriate frequency depends on your individual oral health status, risk factors for dental disease, age, and any symptoms you may be experiencing. Current guidelines emphasize individualized assessment rather than routine schedules.

Factors affecting X-ray frequency

Your dentist will consider several factors when determining how often you need X-rays:

Cavity risk: Patients with a history of frequent cavities, poor oral hygiene, high sugar diet, dry mouth, or other risk factors may need X-rays more often to catch new decay early. Those with excellent oral health and no history of cavities may need less frequent imaging.

Gum disease status: Patients with periodontal disease may need more frequent X-rays to monitor bone levels and assess treatment effectiveness. Healthy patients with no gum problems need less frequent monitoring.

Age and development: Children and adolescents need more frequent X-rays to monitor tooth development and detect problems early. Adults have more stable dentition and typically need less frequent imaging.

Existing dental work: Patients with many fillings, crowns, or other restorations may need more frequent X-rays to monitor for decay under or around restorations.

Symptoms: Any time you have dental symptoms like pain, sensitivity, or swelling, X-rays may be needed regardless of when your last images were taken.

General guidelines

What Happens After My Dental X-Ray?

With digital X-rays, images appear on the computer screen within seconds. Your dentist reviews the images immediately and can show you findings on the screen, explaining any areas of concern. Results are discussed during the same appointment, and any necessary treatment is recommended. You feel completely normal after the X-ray – there are no after-effects from the procedure.

One of the major advantages of modern digital dental X-rays is the immediate availability of results. Unlike medical imaging that may require waiting days for a radiologist's report, dental X-rays are typically reviewed and discussed during the same appointment when they're taken.

Image review and findings

Your dentist will examine each X-ray image carefully, looking for signs of cavities (which appear as dark areas within teeth), bone loss around teeth, infections at root tips, problems with existing dental work, and any other abnormalities. Many dentists will show you the X-rays on a monitor and explain what they see, pointing out any areas of concern.

X-ray images become part of your permanent dental record. They serve as a baseline for comparison at future visits, allowing your dentist to track changes over time. This longitudinal monitoring is valuable for catching slowly progressing conditions like bone loss that might not be apparent on a single set of images.

How you'll feel afterward

You'll feel completely normal after dental X-rays. There are no side effects or after-effects from the procedure. The radiation passes through your body instantly and does not remain in your system. You can eat, drink, and continue your normal activities immediately.

Some patients experience mild jaw fatigue from holding their mouth open or slight gum soreness from the sensor pressing against soft tissue. These minor discomforts resolve quickly and don't require any treatment.

Treatment recommendations

If your X-rays reveal any problems, your dentist will discuss treatment options with you during the same visit. For minor issues like small cavities, treatment can often be scheduled at your convenience. For more urgent problems like infections, prompt treatment will be recommended. If no problems are found, your next set of X-rays will be scheduled according to your individual needs.