Electrophoresis-aided remineralisation system on demineralised dentine

Abstract

Objectives: The aim of this study was to improve therapeutic effects of casein phosphopeptide-amorphous calcium phosphate (CPP–ACP) by introducing electrophoresis, and evaluate remineralisation potentials and safety of electrophoresis–aided CPP–ACP on demineralised dentine. Methods: In vitro after pH–cycling process, 36 teeth with demineralised dentine surfaces were divided into the experimental group which were remineralised by electrophoresis–aided CPP–ACP, and control group remineralised by CPP–ACP. In the experimental and control group, demineralised dentine was remineralised for 3h, 5h or 8h. For verifying remineralisation potentials of electrophoresis–aided CPP–ACP in vivo in a rabbit model, 26 rabbit’s maxillary incisors with acid–etched dentine surfaces were allocated into experimental groups (group A treated with 1.0 mA (n=12); group B treated with 0.5 mA (n=12)), and blank control group without remineralisation (n=2). Samples in experimental groups were remineralised for 3h, 5h or 8h. After remineralisation, remineralised dentine were characterised by scanning electron microscope (SEM). For evaluating pulp vitality, rabbit dental pulp was used for hematoxylin–eosin testing. Results: In vitro, new crystals were densely distributed along collagen fibers within dentine collagen matrix in the experimental group after 5h remineralisation (Fig. 1B). Exposed dentinal tubules were nearly occluded after 8h remineralization (Fig. 1C). While in the control group, profile of demineralised dentine could be observed, and dentinal tubules were still exposed after 8h remineralisation (Fig. 1A). In vivo, the deposition of new crystals on acid–etched dentine increased with remineralisation duration and current strength. After 5h remineralisation in group A (Fig. 1F) and 8h remineralisation in group B (Fig. 1J), acid–etched dentine was completely remineralised by covering a thick layer of new crystals. Additionally, hematoxylin-eosin stain demonstrated no obvious inflammatory reaction in experimental groups (Fig. 2). Conclusions: Electrophoresis could effectively improve therapeutic effects of CPP-ACP and increase its speed in remineralisation. Electrophoresis-aided CPP-ACP remineralisation system could be a potential option in managing dentine demineralisation.