Comparative radiopacity of flowable resin composites

Objective: This in vitro investigation aimed to determine the radiopacity o f eight recently introduced "flowable" restorative resin composites and to compare their radiodensities to those of enamel, dentin, and a widely used composite marketed for universal application in anterior and posterior teet h. Method and materials: A total of 45 composite specimens were fabricated in cylindrical molds and exposed to a curing light for 120 seconds. Two met hods were used to determine radiopacity: a transmission densitometer and a computer-assisted densitometric image analysis station. Results: Of the eig ht flowable resin composites tested, only three exhibited a radiopacity equ al to or greater than that of enamel, a widely followed guideline for clini cians' diagnostic ability The radiopacity of the remaining five materials w as not statistically significantly greater than that of dentin. Conclusion: The level of radiopacity of the tested flowable composites was variable; t hose with low radiodensity should be avoided in Class II restorations, wher e a clear determination of recurrent caries by the examining clinician coul d be compromised.