RADIOPACITY OF DUAL-CURED AND CHEMICAL-CURED RESIN-BASED CEMENTS

Purpose: The objective of this study was to determine radiopacity valu es of a group of resin-based cements and to compare them to those of e namel and dentin. Materials and Methods: Three specimens 2.5 mm thick were prepared from each of 18 cements (nine chemical-cured and nine du al-cured). Three tooth sections 2.5 mm thick were cut from extracted m olars. Specimens and tooth sections were divided into three matching g roups. Following standard radiographic techniques, images of each grou p of specimens, along With an aluminum step wedge were obtained. Optic al density readings for each material were determined with a transmiss ion densitometer. Radiopacity values were subsequently calculated as e quivalents al aluminum thickness. Results: Analysis of variance indica ted significant differences in radiopacity values among the materials (P < 0.0001). four dual-cured cements (Variolink, Geristore, Enforce, and Nexus) had radiopacity values significantly greater than that of e namel, while two (Choice and Adherence) had radiopacity values similar to enamel, For the remaining three dual-cured cements, Duolink had a radiopacity value significantly lower than that oi enamel but higher t han that oi dentin, while both Lute-it and Resinomer had values simila r to dentin. For the chemical-cured cements, five materials had radiop acity values significantly higher than enamel (Sealbond, Advance, Scot chbond, Cement-rt, and Dyract-Cem), while two had values significantly lower than enamel but higher than dentin (Biomer and Panavia 21). The remaining two cements had radiopacity values significantly lower than dentin. Conclusion: For a group of 18 resin-based cements, some had r adiopacity values similar to or significantly lower than that oi denti n.