In vitro and in vivo evaluation of electrophoresis-aided casein phosphopeptide-amorphous calcium phosphate remineralisation system on pH-cycling and acid-etching demineralised enamel

Casein phosphate-amorphous calcium phosphate (CPP-ACP), as a remineralisation agent, is extensively used in managing demineralised enamel; however, its remineralisation kinetics is low. This study aimed to improve remineralisation kinetics of CPP-ACP by introducing a rapid remineralisation method with electrophoresis. In vitro, a pH-cycling enamel model was used to test remineralisation potentials of electrophoresis-aided CPP-ACP. For verifying remineralisation potentials of electrophoresis-aided CPP-ACP in vivo in a rabbit model, acid-etched enamel surface on rabbit maxillary incisors was remineralised by electrophoresis-aided CPP-ACP with 1.0 mA (group A) or 0.5 mA (group B). Both in vitro and in vivo, it was observed that electrophoresis was benefit to improve remineralisation kinetics of CPP-ACP, and the demineralised enamel was completely remineralised after 5 h. The Ca/P ratio in remineralised enamel consisted with that of hydroxyapatite, the microstructure in native enamel. Meanwhile, in vivo the micro-hardness of acid-etched enamel in group A (322.55 ± 31.90) and group B (322.55 ± 31.90) recovered up to the value of native enamel after 5 h remineralisation (p > 0.05). The Hematoxylin-eosin stain demonstrated that the electric field used in this study was safe on rabbit dental pulp. Therefore, this efficient and safe method has the potential to be applied in treating enamel deminerlisation.