Use of QLF In Vitro to Assess Sealed Caries Lesions

There is strong evidence for the effectiveness of sealants in preventing caries. However, one of the major barriers in sealant utilization is the concern of sealing over caries lesions. Monitoring of sealed caries lesions could help address this concern. Objective: To evaluate the effect of clear sealant placement on detection and quantification at one point in time of different stages of caries lesion severity using Quantitative Light-Induced Fluorescence (QLF). Method: Fifty permanent molars were selected using the visual International Caries Detection and Assessment System criteria (ICDAS). Lesion severity scores ranged from 0-4 (10 teeth/category). Teeth were randomly numbered, and after brushing with water and drying for at least 10 seconds, baseline images were acquired using QLF. The occlusal surfaces were then sealed (Helioseal Clear Chroma, Ivoclar Vivadent) according to the manufacturer's instructions. A second QLF image was acquired of the sealed fissures. Images were analyzed for lesion average fluorescence loss, (ΔF [%]), size (S [mm²]), and ΔQ [%xmm²]. For the purposes of this study fluorescence radiance levels of less than 70% of reconstructed sound fluorescence radiance levels were considered to be caries. Results: Lesions appeared larger/more severe after sealant placement with significant (p<0.05) strong correlations between before and after sealant placement for all QLF measurements [r=0.81, 0.97, and 0.97 for ΔF, S and ΔQ, respectively]. Furthermore, higher QLF values were associated with higher visual ICDAS scores, regardless of sealant presence (e.g. the correlation between ICDAS score and ΔQ before and after sealant placement was r=0.58 and r=0.64, respectively). Conclusion: Different stages of caries lesion severity can be observed and objectively quantified using QLF after sealant placement. This study was supported by NIH grant R21 DE018115-01.