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Measuring the Radiopacity of Luting Cements, dowels, and Core Build‐up Materials with a Digital Radiography System Using a CCD Sensor
Author(s) -
Rasimick Brian J.,
Gu Steven,
Deutsch Allan S.,
Musikant Barry Lee
Publication year - 2007
Publication title -
journal of prosthodontics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.902
H-Index - 60
eISSN - 1532-849X
pISSN - 1059-941X
DOI - 10.1111/j.1532-849x.2007.00209.x
Subject(s) - radiodensity , materials science , digital radiography , radiography , core (optical fiber) , luting agent , cement , composite material , medicine , radiology , adhesive , bond strength , layer (electronics)
Purpose:This study assessed the radiopacity of five luting cements, five dowels, and five core build‐up materials using two target distances.Materials and Methods:Materials were analyzed using a modified version of ISO protocol 4049. samples 1 mm thick were digitally radiographed alongside a stepwedge of aluminum alloy 1100 using a Trophy RVG‐4 CCD sensor and 70 kVp X‐ray generator. The gray‐scale values of the stepwedge and sample were converted to X‐ray absorbencies. The relationship between X‐ray absorbance and aluminum thickness was linear for thicknesses less than 10 mm and followed a power‐law relationship above 10 mm. These relations were used to convert the absorbencies of the samples into aluminum thicknesses. The radiopacity data was subjected to ANOVA/Student–Newman–Keuls testing.Results:All materials were more radiopaque than equivalent thicknesses of aluminum. Each product category contained a wide range of radiopacities. Syringe‐dispensed materials tended to be less radiopaque than materials dispensed by mechanically assisted syringe or mixed by hand ( p < 0.01). Target distance did not affect the measured radiopacity so long as the exposure time was suitably adjusted ( p = 0.86).Conclusions:All luting cements and core materials met or exceeded the ISO minimums. The tested metal‐reinforced glass ionomer core build‐up materials were extremely radiopaque. Some publications suggest that excessively radiopaque core materials can hinder a clinician's ability to spot voids or marginal defects.