The Experimental Caries Detector Containing Polypropylene glycol

Objectives: We reported that the sclerotic dentin was stained by the caries detector and sound dentin was exposed on the cavity wall when the pink-stained dentin was completely removed. The sclerotic dentin should be preserved because the dentin adhesive exhibited the superior efficacy to the sclerotic dentin compared to that to the sound dentin. The purpose of this study was to evaluate the effect of the experimental caries detector composed of polypropylene glycol and acid red. Methods: The Micro Vickers Hardness (MVH) of the extracted human dentin was measured on the longitudinal section surface from the pulp chamber to the caries region using a micro hardness tester. Then a dentist with five-year clinical experience removed the caries dentin based on the tactile sensitivity, staining by conventional and experimental caries detector. The MVH of remaining dentin cavity wall was determined by observing the indentations adjacent to the cavity wall. The microstructure of the remaining dentin was observed using a SEM and the possibility of bacteria survival was examined by Gram stained specimen. Results: The MVH of the remaining dentin cavity wall after removal of caries dentin were (25.5 ± 7.8 : tactile sensitivity, 32.7 ± 8.2 : experimental caries detector, 44.7 ± 6.6 : conventional caries detector) statistically significant (p<0.001, One-way ANOVA Fisher's PLSD). The dentin tubules of the cavity wall were completely closed with rod-like or cubic structure substances after the caries dentin was removed based on the experimental caries detector. In addition, the bacteria were not observed regardless of the three guides for caries dentin removal employed. Conclusions: The caries-infected dentin was completely removed and the sclerotic dentin was possible to be preserved by the guide of the staining with the experimental caries detector containing polypropylene glycol.