Why CBCT Scan Quality Dental Practice Teams Must Get Right
CBCT scan quality dental practice teams achieve directly determines whether a radiology report can be confident or must be qualified. Every practice that owns a cone beam CT scanner knows the frustration: you take a scan, upload it for reporting, and then discover that motion blur or metallic scatter has obscured the region of interest. The result is a delayed report, a recommended rescan, another radiation exposure, and a frustrated patient.
This guide walks your team through practical steps to ensure consistently reportable scans. From patient positioning and field of view selection to exposure settings and pre-submission quality checks, every step matters. When you send a volume for consultant radiologist reporting, these protocols ensure a comprehensive, confident report comes back.
Patient Positioning: The Foundation of Reportable Scans
Patient positioning is the single biggest factor your team can control. A perfectly calibrated scanner with optimal exposure settings will still produce a non-diagnostic volume if the patient moves. CBCT scans typically require 15 to 40 seconds of stillness. Even sub-millimetre movement introduces double contours in cortical bone that degrade the entire dataset.
Head stabilisation protocols
Use every stabilisation aid your scanner provides. Chin rests, forehead supports, and temple clamps all reduce involuntary movement. Adjust these for each patient rather than relying on a single default position. For anxious patients, take time to explain the process before positioning. A calm, prepared patient is far less likely to move mid-scan. The SEDENTEXCT guidelines identify adequate head fixation as the most important step in avoiding motion artefacts.
Removing artefact sources before scanning
Ask patients to remove glasses, earrings, necklaces, hearing aids, and removable dental appliances. Partial dentures, retainers, and even chewing gum all cause problems. Metal objects in the scan field create scatter and beam-hardening artefacts. These can obscure anatomy and mimic pathology. A brief checklist at the chair saves considerable time. For more detail on how artefacts affect diagnostic accuracy, see our guide to CBCT image artefacts.
Positioning for specific clinical indications
Different clinical questions call for different positioning approaches. For airway assessments, ask the patient to swallow just before acquisition. This places the tongue in a natural resting position. For anterior mandibular imaging, adjust the chin tilt to avoid superimposing the cervical spine. For TMJ studies, confirm both condyles sit within the field of view before exposing.
How FOV Selection Affects CBCT Scan Quality Dental Practice Outcomes
Choosing the right field of view is one of the most important decisions before each scan. An FOV that is too large captures unnecessary anatomy. It increases radiation dose and introduces more scatter and noise. An FOV that is too small risks missing relevant anatomy. It may require a second exposure. Both outcomes compromise diagnostic value.
Matching FOV to the clinical question
Select the smallest field of view that fully covers the region of interest. For a single tooth endodontic assessment, a small FOV of 4 x 4 cm to 6 x 6 cm typically suffices. This delivers the highest spatial resolution with the lowest dose. For implant planning across a quadrant, a medium FOV of 8 x 8 cm to 10 x 10 cm is appropriate. For full-arch assessments or orthodontic planning, a large FOV of 13 x 15 cm or above may be needed.
Our CBCT field of view selection guide covers each category in detail.
Using scout views effectively
Most modern CBCT units offer a scout or preview scan. This low-dose 2D projection lets you verify positioning before the full acquisition. Use it every time. A scout view confirms that your target anatomy sits within the selected FOV. It also shows whether unexpected metallic objects are in the field. Where your unit allows, use both anteroposterior and lateral scouts to reduce positioning error.
Exposure Parameters That Protect CBCT Scan Quality Dental Practice Standards
Your scanner’s exposure settings directly affect image quality, diagnostic value, and patient dose. Under IR(ME)R 2017, every practice must demonstrate that exposures follow the ALARA principle. This means doses as low as reasonably achievable while still producing diagnostic images.
Tube voltage (kV)
Higher tube voltage reduces beam-hardening artefacts. It also improves contrast-to-noise ratio near metallic restorations. However, increasing kV also increases patient dose. Research shows that raising voltage from 70 to 90 kVp can increase effective dose by a factor of five. Start with manufacturer-recommended settings for each clinical indication. Avoid adjusting kV without understanding the dose implications.
Tube current and exposure time (mA and mAs)
Tube current affects image noise. Higher mA values produce cleaner images but at a greater dose cost. For most dental CBCT applications, the default mA setting provides an acceptable balance. Consider reducing mA for follow-up scans where less contrast resolution is acceptable. Studies show that changes within the typical mA range have limited effect on artefacts around implants.
Voxel size
Voxel size determines spatial resolution. Smaller voxels (0.075 to 0.15 mm) capture finer detail. They are essential for endodontic assessments and root fracture diagnosis. Larger voxels (0.2 to 0.4 mm) suit implant planning and follow-up imaging. These actually deliver better contrast-to-noise ratios at lower doses. Match voxel size to the clinical question rather than defaulting to the smallest setting. Our dose optimisation guide explains how to build protocol-specific settings into your workflow.
Pre-Submission Checks to Maintain CBCT Scan Quality Dental Practice Standards
Before uploading a scan for reporting, a brief quality check catches problems that would otherwise delay your report. Building this step into your workflow takes less than two minutes per scan. It dramatically improves submission consistency.
A five-point pre-submission review
First, scroll through the axial, coronal, and sagittal slices. Look for double contours along cortical bone margins. If motion blur is present throughout the volume, a rescan may be necessary before submission.
Second, verify that the field of view covers the entire region of interest. Check that no relevant anatomy has been truncated at the edges. Truncation artefacts at the FOV boundary can mimic pathology.
Third, check for avoidable metallic artefacts. If scatter from a removable appliance or jewellery is degrading the target area, rescanning after removing the source is worthwhile.
Fourth, confirm the DICOM metadata is correct. Patient name, date of birth, and study date should match your records. Mismatched metadata slows the reporting workflow and creates governance risks.
Fifth, review overall image brightness and contrast. Unusually dark or washed-out images may indicate incorrect exposure settings. Compare with previous scans on the same unit to spot inconsistencies.
The SEDENTEXCT image grading system
The SEDENTEXCT project recommends grading every CBCT scan on a three-point scale. Categories are Excellent, Acceptable, or Unacceptable. The UK Health Protection Agency (now UKHSA) recommends that no more than 5% of CBCT scans fall into the Unacceptable category. This is a stricter threshold than the 10% applied to conventional radiographs. Tracking reject rates over time gives you an objective measure of your CBCT scan quality dental practice performance.
Building a Quality Assurance Programme for CBCT Scan Quality Dental Practice Compliance
Consistent scan quality requires a structured QA programme. Under IR(ME)R 2017 and CQC standards, practices operating CBCT scanners must maintain a programme covering image quality, patient dose, and equipment performance.
Daily, weekly, and periodic checks
Daily checks should include a visual inspection of image quality on the first scan. Look at sharpness, contrast, and artefacts not attributable to the patient. Log every repeated scan and record the reason. Weekly or monthly reviews of reject data help identify patterns. These may reveal whether a particular operator needs training, whether a protocol produces excessive repeats, or whether the scanner needs servicing.
Periodic checks, typically every one to three years, should include formal acceptance tests using a dental-specific phantom. These measure delivered dose against image quality. The SEDENTEXCT guidelines recommend dental-specific phantoms rather than medical CT phantoms. Medical phantoms do not perform well at dental CBCT dose levels.
Designating a quality lead
Every practice should name one team member as the QA lead for CBCT. This person maintains the QA log, tracks reject rates, coordinates servicing, and ensures all operators have current training. The PHE guidance on the safe use of X-ray equipment recommends keeping QA records as a written log accessible to the whole team.
How Specialist Reporting Improves CBCT Scan Quality Dental Practice Results
Outsourcing CBCT reporting to a consultant radiologist satisfies IR(ME)R practitioner requirements. It also provides a built-in feedback loop on scan quality. When a radiologist reviews your scans regularly, patterns emerge. They spot recurring motion artefacts, FOV selections that miss relevant anatomy, or noisy exposure settings. A good reporting service flags these trends. This helps your team continuously improve.
At 3Beam, every CBCT volume submitted for reporting receives a structured consultant radiologist report. Where scan quality issues affect diagnostic confidence, we provide specific feedback. Over time, practices using structured reporting see their reject rates fall. Their overall CBCT scan quality dental practice standards rise consistently.
If your dental practice owns a CBCT scanner and you want every scan reported by a consultant radiologist, find out how 3Beam’s UK-wide reporting service works.
Frequently Asked Questions
What makes a CBCT scan unreportable?
Severe motion artefact is the most common reason. Significant metallic scatter, truncated anatomy from incorrect FOV selection, and corrupted DICOM files also make scans difficult to report with confidence.
How often should we calibrate our CBCT scanner?
Follow your manufacturer’s recommended schedule. As a minimum, formal equipment testing should occur every one to three years. Combine this with daily visual checks and ongoing reject analysis. PHE guidance extends routine safety test intervals for most dental CBCT equipment to three years.
Do we need a medical physics expert for QA?
IR(ME)R 2017 requires access to a medical physics expert for dose and quality advice. You do not need one on staff. Many practices access MPE support through their equipment supplier or radiation protection adviser.
Can software fix poor scan technique?
No. Metal artefact reduction algorithms can improve image quality in some situations. However, research shows mixed results. Some studies report improved contrast while others show reduced accuracy for root fracture detection. Good acquisition technique remains the foundation of reportable CBCT scan quality dental practice teams can rely on.