Aim: This study aimed to evaluate the effect of pseudocolor filter in micro-computed tomography (CT) images for the detection of proximal and occlusal caries lesions in primary molars.
Materials and methods: For this in vitro analysis, 26 extracted human primary teeth were scanned using a compact micro-CT device (Skyscan 1172, Bruker micro-CT, Kontich, Belgium) and the projection images were reconstructed into cross-sectional slices (NRecon v.1.6.9, Bruker micro-CT, Kontich, Belgium). The original and pseudocolor images were evaluated twice by three calibrated radiologists. The tooth surfaces were scored according to Mejàre et al. criteria. The agreement was assessed by the Kappa coefficient, and the Chi-square test was used to evaluate the association between radiolucent lesion depth in enamel and dentin.
Results: There was a good intra-observer agreement for detecting proximal caries lesions with or without using pseudocolor filter (k >0.60). The inter-examiner agreement had similar results, and the agreement rates were good or moderate for the proximal surfaces. There were no statistically significant differences between the original and pseudocolor images (p >0.05). The pseudocolor filter showed high sensitivity and specificity when compared with the original image with the exception of the occlusal face in enamel.
Conclusion: The pseudocolor filter appears to be a promising enhancement tool for micro-CT images used for the detection of caries lesions in primary molars; even if it was not significantly different from the original images.
Clinical significance: The pseudocolor filter converts grey scale images into color images. It is present in micro-CT software and must increase the diagnostic capacity of detecting caries lesion in occlusal and proximal surfaces.
Keywords: Dental caries; Diagnostic imaging; Primary molars X-ray microtomography..