Remineralization of early enamel caries lesions induced by bioactive particles: An in vitro speckle analysis

•Laser speckle imaging was used to evaluate enamel remineralization induced by bioactive materials.•Treatments based on bioactive remineralizing materials may represent the best approach to repair enamel wihite-spot lesions.•Laser speckle imaging may represent an ideal approach for early detection and assessment of remineralization of early caries lesions. This study aimed at evaluating the remineralization effect promoted by different bioactive fillers on simulated early caries lesions in enamel (ECLE). Forty sound bovine incisors were used to prepare buccal enamel specimens (6 × 6 × 2 mm). The specimens were divided into two areas (3 × 3 mm²): control (CTR) and experimental (EXP). All the enamel specimens were then submitted to a specific protocol for a period of 48 h to induce simulated caries lesions. Subsequently, the specimens were treated for 7 days (2 min, twice a day) with a slurry pastes containing different bioactive particles (P/L ratio: 1 g/mL). All the specimens were analyzed by laser speckle before and after treatments. The results showed after the first analysis that the ECLE had very low average intensity (back-scattered light). Conversely, after application of the bioactive pastes, higher average intensity was always detected; this was comparable to CTR sound specimens. In conclusion, innovative pastes/gels developed for enamel remineralization should contain bioactive particles that when applied daily on early caries lesions may “boost” the remineralization process to reestablish a sound enamel.