MicroCT-based comparison between fluorescence-aided caries excavation and conventional excavation

摘要

Purpose: To evaluate and compare the use of micro-computed tomography (microCT) to investigate the mineral concentration of the treated dentin surface after caries removal with fluorescence-aided caries excavation (FACE) and conventional excavation. Methods: 20 extracted human teeth with dentin caries were bisected through the lesion center into two halves which were distributed to a FACE and a conventional excavation group. Tungsten-carbide round burs were used for both groups. Each specimen was investigated with microCT after excavation. The obtained images of all the specimens were evaluated using Image J. Based on the grey values, the linear attenuation coefficients were calculated. Four resin-embedded solid hydroxyapatite phantoms with the gradually increased mineral concentration were used to obtain a calibration curve and equation. Finally, the mineral concentration values of the superficial dentin of each specimen after removal and sound dentin were calculated. The data were compared with the Student's t-test. Results: The statistical results showed that the linear attenuation coefficient (LAC) of the treated surface was significantly lower (P 0.0001) in the FACE group with a mean value of 2.13 ± 0.33 cm-1. The value of the conventional excavation group was 2.98 ± 0.19 cm-1. The LAC of sound dentin was 3.89 ± 0.10 cm-1. By using the calibration equation, the calculated mineral concentration of the superficial dentin after caries removal were 0.68 ± 0.14 g/cm3 in the FACE group and 1.05 ± 0.08 g/cm3 in the conventional excavation group. The mineral concentration of sound dentin was 1.44 ± 0.04 g/cm3. The mineral concentration of the superficial dentin after caries removal in the FACE group was about 47% of that of sound dentin, while the value in the conventional excavation group was approximately 73% of that of sound dentin. Under the conditions of this in vitro study, the results of the microCT evaluation may imply that FACE was more conservative than conventional excavation.