RESUMO
Objective This study aimed to assess the validity of DIAGNOdent as a diagnostic device for the detection of secondary dental caries underneath different types of restorations. Methods A total of 60 extracted human permanent molars were used in this experimental study (30 sound teeth and 30 teeth with proximal caries); 20 teeth (10 sound and 10 carious) were randomly allocated into one of three restoration groups: composite, amalgam, or resin-modified glass ionomer (RMGI). All teeth were examined using both KaVo DIAGNOdent Classic and digital radiographic sensors. Results In the composite-restored teeth, DIAGNOdent showed excellent sensitivity (90%) and specificity (90%). On the other hand, digital radiography had high sensitivity (80%) and poor specificity (20%). In amalgam-restored teeth, DIAGNOdent showed low sensitivity (30%) and excellent specificity (100%), while radiographs showed good sensitivity (70%) and low specificity (30%). In the RMGI-restored teeth, DIAGNOdent had excellent sensitivity (100%) and 70% specificity, while digital radiography had poor sensitivity (30%) and excellent specificity (90%). Conclusions DIAGNOdent showed superior results in detecting secondary caries lesions underneath composite and RMGI restorations when compared to digital radiography. On the other hand, radiography emerged as a preferable method for the detection of secondary caries underneath amalgam restorations. Based on our findings, DIAGNOdent can be used in dental clinics for the early diagnosis of hidden secondary caries underneath composite and RMGI restorations.