The effect of lesion size, restorative material, and film speed on the detection of recurrent caries

The purpose of this investigation was to study the effect of the size of carious lesions, radiographic density of composite and amalgam restorative materials, and film speed on the radiographic detection of simulated recurrent caries. Radiographs were made of extracted premolars with either large or small recurrent carious lesions simulated adjacent to Class II amalgam or composite restorations with both E-speed and D-speed intraoral film. For each restorative material, teeth that had no simulated caries were compared with teeth that had small and large simulated caries. Recurrent caries is detected best when the lesion is adjacent to radiopaque composite restorations, and detection is poorest when the lesion is next to radiolucent composite restorations. Large carious lesions are identified correctly more often than small lesions, although many lesions are not detected at all, especially those adjacent to radiolucent composite materials. There is no difference between E-speed and D-speed film for the detection of recurrent carious lesions.