title: Comparative radiopacity of flowable resin composites.
abstract: OBJECTIVE
  This in vitro investigation aimed to determine the radiopacity of 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 teeth.
  
  
  METHODS
  A total of 45 composite specimens were fabricated in cylindrical molds and exposed to a curing light for 120 seconds. Two methods were used to determine radiopacity: a transmission densitometer and a computer-assisted densitometric image analysis station.
  
  
  RESULTS
  Of the eight flowable resin composites tested, only three exhibited a radiopacity equal to or greater than that of enamel, a widely followed guideline for clinicians' diagnostic ability. The radiopacity of the remaining five materials was not statistically significantly greater than that of dentin.
  
  
  CONCLUSIONS
  The level of radiopacity of the tested flowable composites was variable; those with low radiodensity should be avoided in Class II restorations, where a clear determination of recurrent caries by the examining clinician could be compromised.
authors.affiliation: Department of General Dentistry, Lackland Air Force Base, Texas 78236-5551, USA.
authors.forename: D F
authors.initials: DF
authors.lastname: Murchison
authors.forename: D G
authors.initials: DG
authors.lastname: Charlton
authors.forename: W S
authors.initials: WS
authors.lastname: Moore
mesh_terms: D015502:Absorptiometry, Photon; D000704:Analysis of Variance; D003188:Composite Resins / Q000737:chemistry*; D003287:Contrast Media; D003731:Dental Caries / Q000175:diagnosis / Q000628:therapy; D003793:Dental Restoration, Permanent / Q000379:methods; D006801:Humans; D011861:Radiography, Dental; D012008:Recurrence; D012212:Rheology; D014783:Viscosity
chemical_list: D003188:Composite Resins; D003287:Contrast Media