Quantitative determination of radio-opacity: Equivalence of digital and film X-ray systems

Nomoto, Rie; Mishima, Atsushi; Kobayashi, Kei; McCabe, J.F.; Darvell, B.W.; Watts, David C.; Momoi, Yuichi; Hirano, S.

doi:10.1016/j.dental.2007.08.005

Cited by 40 publications

(39 citation statements)

References 16 publications

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“…As a result, if a digital technique is used, it is not necessary to measure the absorbance of the step wedge in every radiograph as long as the target distance and exposure remain unchanged 16) . The digital image analysis has been considered of the same accuracy as transmission densitometry and can be equivalent to film but with less noise, providing precise and trustworthy numerical values and comparative radiodensity studies 8,12,13,[19][20][21] . In transmission densitometry we obtain optical density, which is a logarithmic measure of the ratio of transmitted to incident light through the film image, while in digital image analysis we have radiographic density directly, because the pixels already have their determined gray shades, directly providing the values at a scale of 0 to 255 through the program 12,16) .…”

Section: Discussionmentioning

confidence: 99%

“…Several types of sensor may be used: charge-coupled devices (CCD), complementary metal oxide semiconductor (CMOS) and photo-stimulable phosphor plates (imaging plates). The most important advantage of digital clinic radiographic systems is the greater sensitivity of the detector in comparison with silver halide film, which results in decreased exposure (radiation dose) of the patient 8) . In digital imaging, the gray scale is inverted in comparison with optical density such that white is allotted a value of 255 (for an 8-bit image) and black is 0.…”

Section: Introductionmentioning

confidence: 99%

“…Dental diagnosis relies on radiology, and it is essential to distinguish intraoral placed material, such as composite resin or cement, from surrounding anatomical structures. Radiopacity of the material must be sufficiently different from tooth tissue to be distinguished equally it must be radiopaque enough that it can be distinguished from a void 8) . According to the International Standards Organization (ISO), the radiopacity of material should be equal to or greater than the same thickness of aluminum and should not be less than 0.5 mm of any value claimed by the manufacturer 9) .…”

Section: Introductionmentioning

confidence: 99%

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Radiopacity of composite dental materials using a digital X-ray system

Dukić

Delija²,

Derossi

et al. 2012

Dental Materials Journal

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The aim of this study was to evaluate the radiopacity of 32 current dental composite materials with digital technique. Digital radiographs with CCD sensor along with an aluminum step wedge, 1-mm-thick tooth slice and 1mm thick composite specimen were taken in five different combinations of exposition/voltage. The radiopacity in pixels was determined using Digora 2.6. software. The equivalent in thickness of aluminum for each material was then calculated from the calibration curve. 74.9% of all tested materials in all exposure combinations had radiopacity between 2 mm and 4 mm aluminum equivalent. The radiopacity of composites ranged from 0.61 mm Al (Gradia Direct Anterior) to 4.78 mm Al (Te-Econom). The average radiopacity for enamel and dentine was 2.05 and 1.11 mm Al. The use of digital technique for radiopacity is an easy, reliable, fast and precise way to analyze different dental materials. Most of the tested composite materials fulfill the requested criteria for radiopacity with a few exceptions.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Radiopacity of composite dental materials using a digital X-ray system

Dukić

Delija²,

Derossi

et al. 2012

Dental Materials Journal

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“…16,30,31 Digital image analysis is considered to have the same accuracy as transmission densitometry and can produce measurements equivalent to those obtained with film with reduced noise, providing precise and trustworthy numerical values for comparative radiodensity studies. 19,22,[31][32][33][34] Transmission densitometry measures optical density, a logarithmic measure of the ratio of transmitted to incident light through the film image. In digital image analysis, we measure radiographic density directly using the gray scale of the pixels, measuring the values on a scale of 0 to 255 using the computer software.…”

Section: Discussionmentioning

confidence: 99%

Radiopacity of Flowable Composite by a Digital Technique

Dukić

Lešić²,

Dubravica³

et al. 2013

Operative Dentistry

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SUMMARY The aim of this in vitro study was to evaluate the radiopacity of 19 current dental flowable composite materials by a digital technique. Digital radiographs were obtained with a CCD sensor using an aluminum step wedge, a 1-mm-thick tooth slice, and a 1-mm-thick flowable composite specimen using five different combinations of exposure and voltage. The radiopacity in pixels was determined using Digora 2.6. software. The equivalent thickness of aluminum for each material was then calculated based on the calibration curve. All of the tested flowable composite materials had higher radiopacities than that of dentin, but in almost every combination of exposure and voltage, there were some composite materials that exhibited radiopacities equal to or slightly greater than enamel p>α; α=0.01). Of the flowable composite materials tested, 37% showed lower radiopacities than enamel, and 21% of the tested materials had higher radiopacities than the 3-mm aluminum equivalent. The highest radiopacity at all exposure values was produced by the Majesty Flow and Charisma Opal Flow materials, which had radiopacities almost twice that of enamel. Flowable composite materials should have radiopacities greater than that of enamel (ISO 4049), an important consideration for the introduction of new materials to the market. The digital radiopacity analysis techniques used in this study provide an easy, reliable, rapid, and precise method to characterize radiopacity of dental flowable composite materials.

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“…However, in the present work, R was calculated as the ratio of the linear attenuation coefficient (l) for the cement (slope of the linear regression plot of the logarithm of OD of cement disc versus cement disc thickness) to l for Al (slope of the linear regression plot of OD of Al step-wedge versus Al step-wedge thickness) and expressed as equivalent Al% [36]. The normalized radiopacity (R 0 ) was computed as the ratio of R to the mass fraction of the radiopacifier in the cement powder (9.1 wt/wt% BaSO 4 for each cement group).…”

mentioning

confidence: 99%

A Daptomycin-Xylitol-loaded Polymethylmethacrylate Bone Cement: How Much Xylitol Should Be Used?

Salehi

Parker

Lewis

et al. 2013

Clinical Orthopaedics &Amp; Related Research

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Background The rate of release of an antibiotic from an antibiotic-loaded polymethylmethacrylate (PMMA) bone cement is low. This may be increased by adding a particulate poragen (eg, xylitol) to the cement powder. However, the appropriate poragen amount is unclear.Questions/purposes We explored the appropriate amount of xylitol to use in a PMMA bone cement loaded with daptomycin and xylitol. Methods We prepared four groups of cement, each comprising the same amount of daptomycin in the powder (1.36 g/40 g dry powder) but different amounts of xylitol (0, 0.7, 1.4, and 2.7 g); the xylitol mass ratio (X) (mass divided by mass of the final dry cement-daptomycin-xylitol mixture) ranged from 0 to 6.13 wt/wt%. Eight mechanical, antibiotic release, and bacterial inhibitory properties were determined using three to 22 specimens or replicates per test. We then used an optimization method to determine an appropriate value of X by (1) identifying the best-fit relationship between the value of each property and X, (2) defining a master objective function incorporating all of the best fits; and (3) determining the value of X at the maximum master objective function.

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Quantitative determination of radio-opacity: Equivalence of digital and film X-ray systems

Cited by 40 publications

References 16 publications

Radiopacity of composite dental materials using a digital X-ray system

Radiopacity of composite dental materials using a digital X-ray system

Radiopacity of Flowable Composite by a Digital Technique

A Daptomycin-Xylitol-loaded Polymethylmethacrylate Bone Cement: How Much Xylitol Should Be Used?

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