Early caries detection methods according to the depth of the lesion: An in vitro comparison

Ld tended to be significantly deeper according to the demineralizing period (p < 0.05). The ΔF significantly decreased (p < 0.05) and the ΔL* significantly increased with increasing the demineralizing period (p < 0.05). More shallow lesions (Ld≤200 μm) showed a strong relationship between ΔF and Ld (r = -0.898, p < 0.001), while there was a strong relationship between ΔL* and Ld in deeper lesions (Ld>200 μm) (r = 0.858, p < 0.001). Our findings show that QLF system is a more efficient device for shallow early caries detection and that the spectrophotometer is a more stable device for the detection of deeper lesions.