Medical imaging notice: Digital dental radiography uses ionising radiation. Images should be selected for an individual clinical need, using optimised equipment and exposure settings. “Digital” does not mean radiation-free.
What is a digital dental X-ray?
A digital dental X-ray records the pattern of X-rays passing through teeth and surrounding structures with an electronic sensor or photostimulable phosphor plate instead of conventional film. Software displays the image promptly and allows calibrated viewing, storage and secure transfer. The underlying radiation physics remains the same as for film radiography.
Digital processing can adjust brightness, contrast and magnification, but it cannot recover anatomy that was not captured or correct severe positioning errors. Enhancement may support viewing but can also exaggerate noise and should not replace diagnostic training.
Main image types
- Bitewing: shows crowns and crestal bone, commonly for proximal caries and bone-level assessment.
- Periapical: shows the complete tooth, root and surrounding apical tissues.
- Occlusal: covers a larger region of one arch for selected localisation or developmental questions.
- Panoramic: provides a broad two-dimensional overview of jaws and teeth.
- Cephalometric: supports selected orthodontic and craniofacial measurements.
One view does not substitute for another. The dentist selects the minimum image set that can answer the clinical question.
When are radiographs needed?
Dental X-rays may help assess decay between teeth, bone levels, root anatomy, infection, impacted teeth, trauma, development and existing restorations. They should follow a history and examination. Fixed annual schedules for every patient are not evidence-based; intervals depend on age, disease risk, symptoms and previous findings.
Current recommendations emphasise reviewing existing images before prescribing new ones. A transfer patient does not automatically need a new full series when recent diagnostic images are available.
Radiation and optimisation
Digital receptors can permit lower exposures than some film systems, but actual dose depends on sensor sensitivity, collimation, exposure settings, equipment quality, positioning and retakes. Rectangular collimation for intraoral images can restrict the beam to the receptor area. Optimisation aims for a diagnostically adequate image, not the brightest or most detailed image possible.
Radiation risk from an individual dental exposure is generally low but not zero. Cumulative exposure and unnecessary repeats should be avoided. The correct principle is justification and optimisation for each examination.
Sensor and plate differences
Solid-state sensors display an image immediately and may require less exposure, but they are relatively thick and connected sensors have a cable. Phosphor plates are thin and flexible like film but must be scanned and can be scratched, bent or exposed to ambient light. Both require validated barriers, cleaning and infection-control procedures.
Patient comfort varies with mouth size, gag reflex, anatomy and holder design. A wireless sensor removes the cable but is not necessarily more comfortable. Correct holders reduce distortion and retakes.
What radiographs can and cannot show
Radiographs show differences in mineral density as a two-dimensional projection. They do not show every early lesion, crack, pulp condition or soft-tissue problem. Caries detection varies by lesion depth and location; early enamel disease may be missed. A dark area is not automatically active decay and must be interpreted with clinical findings.
Overlapping contacts, foreshortening, elongation and cone cuts can make an image nondiagnostic. Retaking should be based on whether the error prevents the required interpretation, not on cosmetic perfection.
Digital X-ray versus CBCT
Intraoral and panoramic radiographs are two-dimensional and usually remain first-line imaging. CBCT supplies three-dimensional information but often at a higher dose and with different limitations. CBCT is not a superior replacement for every bitewing or periapical image. It should be reserved for questions in which the added dimension is likely to affect care.
Pregnancy and special situations
Necessary dental radiography can be performed with appropriate justification and optimisation during pregnancy; delaying diagnosis of acute infection can also carry risk. Patients should tell the team if they are or may be pregnant so that clinical urgency, local regulations and protective measures can be considered. The decision should not be based on fear or a blanket rule.
Image storage, transfer and privacy
Digital images should be stored in the original diagnostic format with patient identity, acquisition date and exposure information where available. Screenshots or compressed messaging-app copies may lose detail. Patients can request copies for continuity of care, but the receiving clinician must decide whether they remain diagnostically adequate.
Artificial intelligence and enhancement
AI tools may highlight possible caries, bone loss or other findings, but performance varies with dataset and device. They can produce false positives and false negatives. AI output should be treated as decision support, not an autonomous diagnosis, and does not justify taking an image that was not otherwise clinically indicated.
Questions to ask
- What finding or decision requires this image?
- Are recent usable radiographs already available?
- Which view is the lowest-exposure option that answers the question?
- How are retakes and equipment quality controlled?
- Can I obtain the original image files?
- Will any AI result be reviewed by the dentist?
What to expect during intraoral imaging
The operator places a covered sensor or plate inside the mouth using a holder, aligns the X-ray tube and briefly activates the exposure from a protected position. You may be asked to bite gently and remain still. Tell the operator if the holder causes sharp pain or triggers gagging; a different receptor size, holder or sequence may help without compromising the required view.
The image appears quickly, but immediate display does not guarantee diagnostic quality. The operator checks coverage, contact overlap, sharpness and exposure. A repeat should occur only when the original cannot answer the clinical question, with the positioning error corrected first.
How dentists interpret an image
Interpretation uses an appropriate diagnostic monitor and viewing environment. The dentist evaluates the full image systematically, compares it with older images when available and combines it with symptoms, testing and examination. Changes in projection can make bone levels or lesion size appear different, so apparent progression should be assessed cautiously.
A radiograph records one moment and mineral change may lag behind disease activity. For example, an area of demineralisation may be inactive, while early active decay may not yet be visible. Treatment should not be based on one highlighted pixel or an automated outline alone.
Quality assurance and infection control
Clinics should test X-ray equipment, receptors, displays and protective systems at defined intervals. Exposure charts should be matched to receptor and patient size. Staff training and retake audits help identify recurring positioning or processing problems. For phosphor plates, scratches and incomplete erasure can produce artefacts that mimic findings.
Sensors and plates need barriers and manufacturer-compatible cleaning because they cannot always be heat sterilised. Holders that contact mucosa must be single-use or reprocessed appropriately. Infection-control shortcuts are not justified by the speed of digital imaging.
Comparing images over time
Longitudinal comparison is most reliable when projection geometry and image type are similar. Consistent bitewing holders can help reveal genuine changes rather than angulation differences. The date, side and view should be labelled correctly. Original files should remain available even when enhanced copies are created for explanation.
Evidence summary
Digital radiography offers rapid, transferable diagnostic images and can support dose reduction when paired with correct equipment and technique. Its value comes from patient-specific selection and interpretation; digital technology does not remove radiation risk or the need for clinical examination.
Sources
- ADA and AAOMR recommendations for dental radiography and CBCT selection
- Optimising radiation safety in dentistry
- Digital sensor image quality, radiation dose and comfort
- Radiographic caries detection: systematic review and meta-analysis
Prepared as general educational information. A dentist must justify each exposure and interpret it with the clinical examination.