Effect Of Phosphate Group On Remineralization Of Early Enamel Caries Regulated By Amelogenin Peptide

Amelogenin is the main extracellular matrix protein in the mineralization of tooth enamel.Biomimetic remineralization is the process of tooth remineralization induced by organic matrix to obtain highly biomimetic dental hard tissues in morphology and function.In previous studies,we found that recombinant Amelogenin peptide could promote the remineralization of early enamel caries,and has the ability to combine with calcium ions to form stable ACP,inhibit the premature formation of calcium phosphate crystals in the solution,eventually formed highly ordered hydroxyapatite crystals in the mineralized solution.In addition,the recombinant Amelogenin peptide could penetrate into the subsurface area of the caries.The single phosphate group on the N-terminus of amelogenin can combine with calcium ions,stable mineral nucleation precursor-amorphous calcium phosphate(ACP),prevent the deposition of disordered crystal.Therefore,we think that the recombinant Amelogenin peptide may play a role as? ion carrier ' in the process of remineralization of early enamel caries.Objective: To verify the effect of phosphate group in the remineralization process of early enamel caries regulated by amelogenin peptide,provide a theoretical basis for the development of anti-caries materials which could induce the formation of biomineralized tissue with higher-order structure in early enamel caries.Methods: Artificial early enamel caries were prepared by fresh extracted,completed and crack-free bovine teeth,randomly divided into 4 groups: Group A: fluorination remineralization solution treatment group;Group B: pure remineralization solution treatment group;Group C: 100 ? g/ml recombinant Amelogenin peptide remineralization solution treatment group;Group D :100 ?g/ml non-phosphorylated recombinant Amelogenin peptide remineralization solution treatment group.Fresh remineralization solution is replaced daily for 12 days.After the remineralization,the transverse microradiography(TMR)is used to determine the mineral loss and demineralization depth before and after each sample's remineralization,thereby calculating the mineral acquirement and mineralization depth of each sample.Results: The mineral acquirement and mineralization depth of the recombinant Amelogenin peptide group with single phosphate group was higher than that of the nonphosphorylated Amelogenin peptide group without phosphate group,and the results were statistically significant(P<0.05).Conclusions: The single phosphate group on the amelogenin N-terminus plays an important role in the regulation of recombinant Amelogenin peptide promoting the remineralization of early enamel caries.