Comparison of conventional and digital radiography for radiometric differentiation of dental cements

Objective: To test the efficacy of conventional radiometry with indirect digital image analysis in the assessment of the relative radiopacity of dental cements used as liners or bases compared to human enamel and dentin. Method and Materials, Disks of 15 different dental cements, 5 mm in diameter and 2 mm thick, were exposed to radiation together with 2-mm-thick disks of enamel and dentin and an aluminum step wedge. Density was evalulated by digital transmission densitometry and with the histogram function of an image analysis program following digitization of the radiographs with a flatbed scanner. Results: A higher number of dental cements were discriminated from both dentin and enamel with conventional radiographic densitometer. All the cements examined, except lonoseal (Voco) and lonobond (Voco), were more radiopaque than dentin. With both methods, Chelon-Silver (3M ESPE) had the highest radiopacity and glass-ionomer cements the lowest. Conclusion: Radiodensity of dental cements can be differentiated with a high probability with the conventional radiometric method.