Objective: The available literature concerning systems for occlusal caries detection in primary teeth is limited. The aim of this study was to compare in vitro a ranked scoring system for occlusal caries detection in primary molar teeth with bitewing radiography and to investigate the most accurate cut-off point for dentine caries detection when using this ranked scoring system.
Methods: Sixty primary molar teeth were examined in vitro visually and by bitewing radiography (two examiners) using Ekstrand' criteria.
Results: Histological examination revealed that 13% were sound, 38% had enamel caries and the remainder had dentine caries. Similar accuracy was seen when comparing bitewing radiographs and visual examination for caries detection at the d3 threshold, while visual examination was more accurate at the d1 threshold. The most suitable cut-off for diagnosing caries at the d1 threshold was V1 (no/slight change in enamel translucency after air drying). Either V2 (opacity/discoloration visible without air drying) or V3 (enamel breakdown in opaque/discoloured enamel and/or greyish discoloration) were suitable cut-off points at the d3 threshold.
Conclusion: Visual examination was more accurate than bitewing radiographs for detection at the d1 threshold (the cut-off point of V1). Either V2 or V3 can be used for caries detection at the d3 threshold.