Ultrasond-Mediated Pccp Process For Remineralization Of Artificial Dentin Caries

The hydration layer within caries-like demineralized dentin matrixn (DDM) creats a barrier effect, impeding the rapid permeation of mineralization mediums. This study aimed to overcome this barrier effect using ultrasound for treating artificial dentin caries (ADC) lesion via Polyelectrolyte-Cation Complexes Preprecursor (PCCP) process. Ultrasound-mediated permeation rates of mineralization mediums, such as calcium or phosphate liquid, were evaluated with confocal laser scanning microscopy for screening out the optimal ultrasound treatment duration. Comsol Multiphysics simulations were integrated with experimental data to analyze the mechanism by which ultrasound enhanced permeation of mineralization mediums. After the dentin disks with ADC were treated with mineralization mediums and incubated in artificial saliva for 21 days, they were characterized with micro-CT, scanning electron microscopy, high-resolution transmission electron microscopy with selected-area electron diffraction and nanoindentation testing. Ultrasound greatly enhanced the permeation rate of mineralization medium by the force of acoustic flow field. The calcium and phosphate liquids achieved full-thickness permeation through the DDM via 1h and 5min ultrasonic treatments respectively, demonstrating 2000% and 12000% enhancements compared to that of immersion. After incubation, heavy remineralization within the collagen fibrils and mostly remineralization outside the fibrils were achieved in ADC lesion, whose mechanical strength was recovered to approximately 70% compared to that of natural dentin. The ultrasond could assist in mineralization mediums to break through the barrier effect of caries-like DDM and improve the biomimetic mineralization of ACD. This should shed light on ultrasond-mediated PCCP process for treating dentin caries lesions.