Methods of determining the effective dose in dental radiology

Objectives: To demonstrate the feasibility of GafChromic ® XR-QA2 (ISP Corp., Wayne, NJ) as a dosemeter when performing measurements of the effective dose from three cone beam CT (CBCT) units and to compare the doses from examinations of three common dental clinical situations. A second aim was to compare the radiation doses for three digital panoramic units with the doses for the CBCT units. Methods: The CBCT units used were Veraviewepocs 3De ® (J Morita MFG Corp., Kyoto, Japan), ProMax ® 3D (Planmeca, Helsinki, Finland) and NewTom VGi ® (Quantitative Radiology, Verona, Italy). GafChromic XR-QA2 films were placed between the selected layers of the head and neck of a tissue-equivalent human skull (RANDO ® phantom; The Phantom Laboratory, Salem, NY). The exposure parameters were set using the automatic exposure control function of the units. Depending on the availability, medium and smaller field of view (FOV) scanning modes were used. The effective dose was estimated using the 2007 International Commission on Radiological Protection formalism. Results: The lowest effective dose of a CBCT unit was observed for ProMax 3D, FOV 4 3 5 cm (10 mSv), the highest for NewTom VGi, FOV 8 3 8 cm-high resolution (129 mSv). The range of effective doses for digital panoramic machines measured was 8-14 mSv. Conclusions: This study demonstrates the feasibility of using radiochromic films for dental CBCT and panoramic dosimetry.

Section: Discussionmentioning

confidence: 99%

Using GafChromic film to estimate the effective dose from dental cone beam CT and panoramic radiography

Al-Okshi¹,

Nilsson²,

Petersson³

et al. 2013

“…On the contrary, a comparison with other studies is often difficult because of the use of different dosemeters, measuring locations, phantoms or methodologies. 17 For example, a study by Palomo et al is based on ten TLDs for each measurement, 18 whereas measurements by Pauwels et al are based on 147 and 152 TLDs (for two different phantoms). 19 In conclusion, a more standardized approach would produce relief, especially for the user responsible for finding a radiation exposure as low as reasonably achievable.…”

Section: Discussionmentioning

confidence: 99%

Assessment of the effective doses from two dental cone beam CT devices

Schilling

Ma²

2013

Objectives: This study compares the effective dose for different fields of view (FOVs), resolutions and X-ray parameters from two cone beam CT units: the KaVo 3D (threedimensional) eXam and the KaVo Pan eXam Plus 3D (KaVo Dental, Biberach, Germany). Methods: Measurements were made using thermoluminescent dosemeter chips in a radiation analog dosimetry head and neck phantom. The calculations of effective doses are based on the ICRP 60 and ICRP 103 recommendations of the International Commission on Radiological Protection. Results: Effective doses from the 3D eXam ranged between 32.8 mSv and 169.8 mSv, and for the Pan eXam Plus effective doses ranged between 40.2 mSv and 183.7 mSv; these were measured using ICRP 103 weighting factors in each case. The increase in effective dose between ICRP 60 and ICRP 103 recommendations averaged 157% for all measurements. Conclusions: Effective doses can be reduced significantly with the choice of lower resolutions and mAs settings as well as smaller FOVs to avoid tissues sensitive to radiation being inside the direct beam. Larger FOVs do not necessarily lead to higher effective doses.

“…Some of the compounds used in TLDs include lithium fluoride (LiF), CaSO 4 (calcium sulfate) and CaF 2 (calcium fluoride). 1,6 Radiographic examination is an important component of the diagnostic process in dentistry; still, the possible deleterious effects of ionizing radiation on biological tissues must not be ignored. Digital systems are gradually replacing conventional radiographic films with the advantages of lower radiation doses, as well as time-and storage-saving properties.…”

Section: Introductionmentioning

confidence: 99%

Efficacy of lead foil for reducing doses in the head and neck: a simulation study using digital intraoral systems

Nejaim

Silva

Brasil

et al. 2015

Objectives: To assess the efficacy of lead foils in reducing the radiation dose received by different anatomical sites of the head and neck during periapical intraoral examinations performed with digital systems. Methods: Images were acquired through four different manners: phosphor plate (PSP; VistaScan ® system; Dürr Dental GmbH, Bissingen, Germany) alone, PSP plus lead foil, complementary metal oxide semiconductor (CMOS; DIGORA ® Toto, Soredex ® , Tuusula, Finland) alone and CMOS plus lead foil. Radiation dose was measured after a full-mouth periapical series (14 radiographs) using the long-cone paralleling technique. Lithium fluoride (LiF 100) thermoluminescent dosemeters were placed in an anthropomorphic phantom at points corresponding to the tongue, thyroid, crystalline lenses, parotid glands and maxillary sinuses. Results: Dosemeter readings demonstrated the efficacy of the addition of lead foil in the intraoral digital X-ray systems provided in reducing organ doses in the selected structures, approximately 32% in the PSP system and 59% in the CMOS system. Conclusions: The use of lead foils associated with digital X-ray sensors is an effective alternative for the protection of different anatomical sites of the head and neck during fullmouth periapical series acquisition.