RESUMEN
Objective:To prepare a peptide fluorescent probe based on aggregation-induced emission and to investigate its application in the detection of early caries.Methods:Eight aspartate-serine-serine (DSS) were combined with aggregation-induced emission material to prepare peptide fluorescent probes, and an artificial demineralization model was established in vitro. The samples were immersed in the peptide fluorescent probe solution for 1 min, and a fluorescence imaging system was applied to examine the tooth samples and collect images and fluorescence data. Scanning electron microscopy was also applied to observe the phenotype of the teeth, and electron microscopy was applied to detect the calcium-phosphorus ratio on the enamel surface of the teeth. Polarized light microscopy was also applied to observe the enamel area of the teeth. Results:The fluorescence intensity of demineralized teeth was clearly observed to be lower than that of normal teeth in the peptide fluorescent probe-treated area, and the difference was statistically significant ( P < 0.05). The results of scanning electron microscopy showed that the enamel surface of the demineralized group had more irregular pores, while the enamel surface of the undemineralized group was flatter with only some irregular accumulation of flakes. The results of polarized light microscopy showed that a clear birefringence could be observed in the enamel region of normal teeth, while a black area or the disappearance of the birefringence effect accompanied by a partial black dark shadow could be observed in the enamel region of demineralized teeth. Conclusions:An aggregation-induced luminescence-based peptide fluorescent probe was successfully prepared, which can precisely localize the enamel and show some application value in early caries detection.
RESUMEN
OBJECTIVES: To compare the QLF-D method and the ICDAS and DIAGNOdent techniques for in vitro quantification of occlusal caries and to assess the histological features of the caries. METHODS: One hundred and twenty-two extracted permanent teeth were selected, and the site of interest on the occlusal surface was examined using each detection method. The occlusal sites were classified according to the ICDAS II criteria based on the decision taken by two investigators, who have taken the ICDAS E-learning course. The examined site was then measured using the DIAGNOdent, and the peak value was recorded. In addition, by using the QLF-D, the occlusal site was photographed to obtain the DeltaFmax value. After all assessments were performed, the occlusal sites were vertically sectioned in order to assess the histological features. This was considered the gold standard. The histological criteria were graded using a 4-point scale as follows: S=sound (n=21), E1=limited enamel caries (n=27), E2=caries extending to the dento-enamel junction (n=49), D=caries involving the dentine (n=25). RESULTS: An ICDAS code between 0 and 4 was assigned to all the occlusal sites, and this revealed the QLF-D value, which was between -95 to 0. The DIAGNOdent value was between 8 and 99. The correlation values of QLF-D, ICDAS, and DIAGNOdent with the histological features were 0.68, 0.58, and 0.46, respectively (P<0.01). A highly significant correlation was observed between QLF-D and the gold standard, which showed a moderate correlation and an acceptable correlation was observed with ICDAS (r=0.75, P<0.01). A statistically significant difference was observed in the average QLF-D values of each histological grade i.e., -28.5 (S), -53.7 (E1), -68.1 (E2), and -84.4 (D). CONCLUSIONS: The QLF-D showed a significant correlation with the ICDAS and histological features. Therefore, visual inspection with QLF-D would improve the detection accuracy and ensure early diagnosis of dental caries.