VALIDITY OF RADIOGRAPHS FOR DIAGNOSIS OF SECONDARY CARIES IN TEETH WITH CLASS-II AMALGAM RESTORATIONS IN-VITRO

In the present in vitro study, the validity was determined of bite-win g radiographs for the diagnosis of secondary caries in approximal part s of teeth with class II amalgam restorations in vitro. The study was performed on 47 molars and 49 premolars providing 68 and 69 filled app roximal surfaces, respectively. The teeth were radiographed in a bucco lingual direction to obtain images comparable to bite-wings. Radioluce ncies and radio-opacities were scored as caries. Subsequently the teet h were sectioned (700 mu m) in transverse or sagittal direction and th en the sections were radiographed. Validation was performed against th ese radiographs of sections, on which also radiolucencies and radio-op acities were scored. Statistical analysis of the results revealed sign ificant differences between the validity parameters for molars and pre molars, being for sensitivity 73 and 80%, respectively, for specificit y 90 and 95%, for positive predictive value 95 and 92%, and for negati ve predictive value 58 and 86%. For molars, the results did not differ significantly from the results of our previous study on caries diagno sis in teeth with occlusal fillings. The present experiment showed tha t bitewing radiographs are useful for the diagnosis of secondary carie s under approximal parts of class II amalgam restorations, just as for secondary caries diagnosis adjacent to class I restorations.