Effective Doses of Radiation from Standard Dental Imaging, CBCT, and CT
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Hi Everyone,
Making decisions about dental X-rays is something we all have to do at some point. So, I collected a few studies to compare the approximate radiation doses from different X-ray technologies that a dentist or orthodontist might use. It’s not surprising none of them are from the US...
The overview is that standard x-rays deliver less radiation than CBCT and CBTC delivers less than CT. Although, depending on the setup of the device, the ranges can be quite large especially for CBCT. I didn’t present this data but some studies determined a thyroid collar is worth using.
I think one of the more insidious ways the medical community convinces people radiation is harmless is to say you receive as much radiation as being on a cross country flight as when you are getting a routine X-ray. I know Ray was of the opinion that cosmic radiation at high altitude is essentially harmless because it passes right through the body without interacting much with our tissues. But, this is one of the claims I’ve had more trouble verifying. If anyone has any information on this please post it here.
Li 2013 Patient Radiation Dose and Protection from Cone-Beam Computed Tomography
https://pubmed.ncbi.nlm.nih.gov/23807928/
Method: Anthropomorphic phantom with light sensors inside used to measure absorbed dose of radiation. Tested CBCT device.
Results:
Effective dose CBCT: 61 – 134 uSv
“The results from the direct comparison studies were summarized in Table 2, where the effective dose for panoramic radiography is about 22.0 μSv, for lateral cephalometric examination about 4.5 μSv and for CBCT examnation the effective dose is 61-134 μSv. No study has performed a direct comparison of the effective dose from intraoral and CBCT examinations.In the guidelines provided by the European Academy of DentoMaxillofacial Radiology, the suggested effective dose of one intraoral radiograph is 1.5 μSv. Other studies 20-26 that exclusively estimated the effective dose of conventional dental radiography have demonstrated that the range of the effective dose for a panoramic radiograph is 3.85-38.0 μSv (Table 3), for a lateral cephalometric examination is 1.1-5.6 μSv (Table 4), for posteroanterior cephalometric radiograph, 5.1 μSv, and for one introal examination, 0.65-9.5 μSv (Table 5).
From Summary: Compared with conventional dental radiography, the effective dose of CBCT is several to hundreds of times higher.
Qiang 2018 Estimation of Effective Dose of Dental X-Ray Devices
https://pubmed.ncbi.nlm.nih.gov/30169836/
Method: Anthropomorphic phantom with light sensors inside used to measure absorbed dose of radiation. Tested three devices: CBCT , dental panoramic machine, and intraoral round cone device.
Results:
Effective dose CBCT: 203 uSv
Effective dose Panoramic: 13 uSv
Effective dose Intraoral Round Cone: 5 uSvFrom Discussion: Our study is consistent with other studies which conclude that patient doses from CBCT are much higher than from conventional dental radiography techniques(14–18) and is also close to Granlund’s research which report that the range of effective doses resulted by dental panoramic machine examination is between 19 and 75 uSv(19)”
Shatskiy 2021 Effective Radiation Doses and Radiation Risks from Common Dental Radiographic Panoramic and CBCT Examinations
https://pubmed.ncbi.nlm.nih.gov/34086952/
Method: Anthropomorphic phantom with light sensors inside used to measure absorbed dose of radiation. Tested intraoral examinations with film, digital detectors, panoramic devices, and CBCT.
Results
Effective dose Intraoral: 0.6 – 33.2 uSv
Effective dose Panoramic: 9.4 - 61 uSv
Effective dose CBCT: 79.2 – 1123 uSvFrom Discussion:“In CBCT, reducing the height of the field of view and shielding the thyroid are advisable methods and must be implemented to lower the exposure dose. Although a single CBCT scan can replace the set of conventional dental and panoramic radiographs, a lifetime risk assessment confirms the greater potential radiation detriment associated with CBCT, which can be 23–30 times higher than from panoramic examinations depending on age.”
Khader 2024 Comparing Radiation Doses in CBCT and Medical CT Imaging for Dental Applications
https://pubmed.ncbi.nlm.nih.gov/38882804/
Method: Imaging parameters, such as scan protocols (e.g., field of view, tube voltage, tube current), were retrieved from real life radiology reports from 100 patients that received both CBCT and CT for dental applications. Effective dose was calculated.
Results
Average Effective Dose CBCT: 190 uSv
Average Effective Dose CT: 270 uSvALSO. Maybe dental websites will claim that CBCT delivers LESS radiation than alternative therapies. Obviously, this is misleading and it depends on what it is compared to. But when compared to standard dental imaging it absolutely does not deliver less radiation. Example here: https://advancedperioatl.com/cbct-scan-dentist-vs-x-rays/