Intro
When a dentist calls saying their cone beam images look “grainy,” “blurry,” or “just not like they used to,” the issue often lands on the technician’s desk. Cone beam CT (CBCT) systems are remarkably precise, but small changes in setup, maintenance, or environment can quickly degrade image quality. Understanding how to identify and correct these problems not only helps your clients, but it also builds trust and positions you as an imaging expert.
Why CBCT Image Quality Matters
A CBCT’s value lies in its ability to reveal fine anatomical details. Poor image quality can obscure canals, bone defects, or implant paths, leading to frustration for dentists and re-scans for patients. For technicians, consistent quality is proof that the system is properly calibrated and maintained.
The Usual Suspects
Common image issues stem from three categories: technique, environment, and hardware/software.
Before opening a service ticket or swapping parts, it’s smart to rule out technique first. Many “machine problems” start with how the scan is taken.
Patient Positioning Errors
Even a few millimeters of misalignment can distort anatomy. If the patient’s chin is too high or low, or the head isn’t centered, shadows and elongation appear. Encourage your dental teams to use laser alignment guides and verify that the Frankfurt plane is level before exposure.
Motion Artifacts
Patients sometimes move during the 10–20-second rotation. The result is a double-image effect resembling ghosting or streaks. If this happens, confirm that the seat or chin rest is secure, and check whether the exposure time can be shortened or the scan mode adjusted.
Exposure Settings and Protocols
Underexposure causes noisy, gray images; overexposure washes out contrast. Remind operators that patient size and region of interest matter. Most systems allow preset protocols (small, medium, large adult). Ensuring these are correctly chosen prevents repeat scans and excess dose.
Environmental Factors
Ambient temperature and electrical stability influence sensitive imaging components. Fluctuating voltage can create line artifacts or intermittent detector errors. Recommend dedicated power circuits with surge suppression and, ideally, voltage regulation for CBCT units.
Detector and Flat-Field Calibration
Digital detectors age over time. Regular flat-field calibration ensures uniform response across the panel. If you see vertical banding, dead pixels, or brightness gradients, schedule a calibration or check for issues with the detector.
Tubehead and Generator Health
If artifacts persist after calibration, inspect tube output consistency. A weakening X-ray tube or unstable generator can cause subtle exposure drift. Reviewing exposure logs and measuring mA/kV stability can reveal early signs of failure before total shutdown.
Software Reconstruction Settings
Occasionally, the issue lies in reconstruction parameters. Verify that the system’s reconstruction filters match the scan protocol. Updating or reinstalling reconstruction software can also resolve artifacts that appear after software crashes or power interruptions.
Service Documentation and Preventive Maintenance
Document every adjustment, calibration, or environmental change. Maintaining a detailed service log helps correlate image issues with events like electrical outages or room remodels. Preventive maintenance visits, like checking motion bearings, filters, fans, and grounding, can reduce emergency calls later.
Educating the Dental Team
Technicians who explain why quality issues occur strengthen relationships. Providing quick-reference guides for common image errors empowers staff to self-correct minor issues, keeping their system performing optimally and you top of mind for future upgrades.
Conclusion
CBCT image quality problems rarely stem from a single cause. A structured troubleshooting process including technique first, then environment, then hardware can saves time and reinforces your role as the expert keeping the office’s imaging dependable and compliant. Great imaging equals happy dentists, fewer retakes, and stronger service partnerships.
About ImageWorks
At ImageWorks, we believe dentists deserve imaging technology that delivers exceptional image quality, great pricing, and dependable performance. Our panoramic, cone beam, and intraoral imaging systems are designed to give you crystal-clear diagnostics while keeping ownership simple and affordable.