PROGRESSION OF RADIOPACITIES AND RADIOLUCENCIES UNDER AMALGAM RESTORATIONS ON BITE-WING RADIOGRAPHS

Radiolucent and radiopaque areas in the dentine under amalgam fillings represent demineralized tissue. The aim of this study was to investig ate whether caries progresses in radiolucent and radiopaque areas unde r amalgam fillings, by assessing their enlargement longitudinally on b ite-wing radiographs. Bite-wings from dentitions of persons aged 17, 2 0 and 23 years were compared. For a 3-year evaluation, 365 teeth with class I and class II amalgam restorations were available on bite-wings ; 16 radiopacities, 46 radiolucencies and 28 combinations could be fol lowed longitudinally. All radiopacities remained the same size, 14 rad iolucencies enlarged and 8 combinations enlarged. For a 6-year evaluat ion, 236 filled teeth were available; 10 radiopacities, 30 radiolucenc ies and 11 combinations could be compared longitudinally. All radiopac ities remained the same size, 12 radiolucencies enlarged and 6 combina tions enlarged. Because the radiopaque areas had not enlarged visibly on bite-wing radiographs over 3 or even 6 years, it was concluded that radiopacities may be non-progressing caries. A substantial number of radiolucent areas, with or without concomitant radiopacities, did not enlarge while radiolucent areas are considered as progressing caries.