[Effects of dentine phosphoprotein on remineralization of demineralized dentine].

OBJECTIVE: To investigate the relationship between dentine phosphoprotein (DPP) and remineralization of demineralized dentine. METHODS: (1) Soluble DPP was extracted with 1 mol/L NaCl from demineralized dentine and was evaluated. (2) Soluble DPP was removed with 0.1 mol/L NaCl or was not removed from demineralized dentine sections in human tooth roots. Then all sections were subjected to remineralization treatment, and remineralization degrees were compared by atomic absorption spectrum, SEM and microradiography. RESULTS: (1) Soluble DPP was extracted with 1 mol/L NaCl. (2) Removal of soluble DPP resulted in significantly lower calcium concentration in remineralization solution (P < 0.01), less mean light-absorbed value in demineralized dentin sections by microradiography (P < 0.01). CONCLUSIONS: Soluble DPP may have an inhibiting effect on remineralization of demineralized dentine, this study suggests that the remove of soluble DPP from root caries lesions may enhance their remineralization potential.

[The effect of dentin phosphoprotein on inducing mineralization].

OBJECTIVE: To investigate the effect of dentin phosphoprotein (DPP) in inducing dentinal mineralization. METHODS: Human DPP was combined with EAH-Sepharose 4B beads and its function of inducing mineralization was studied in mineralization system in-vitro. The mineral formed on the surface of the beads was analyzed by scanning electron microscopy (SEM) and the structure was analyzed by X-ray diffraction and plasma emission spectrum. RESULTS: There was mineral formed on the beads with combined DPP and the mineral was calcium phosphates whose ratio of calcium to phosphate was 1.33. The diffractogram of the formed mineral was more similar to hydroxyapatite than to other calcium phosphates. CONCLUSION: When tightly combined with certain support substance, human DPP can induce mineralization.