Biomimetic mineralisation of phosphorylated dentine by CPP-ACP
Available online 25 June 2013
Abstract
Objectives
Casein
phosphopeptide-amorphous calcium phosphate (CPP-ACP) has the potential
to induce the biomimetic mineralisation of dentine collagen fibrils.
This study aimed to demonstrate in vitro the ability of CPP-ACP to form apatite crystals on phosphorylated dentine collagen fibrils.
Methods
Dentine
slices with a 2-mm thickness were prepared from sound human third
molars. The slices were etched with phosphoric acid to expose the
collagen fibres. Sodium trimetaphosphate was then used to phosphorylate
the exposed collagen fibres. CPP-ACP paste was topically applied to the
surface of the phosphorylated slices, which were then immersed in a
metastable calcium phosphate remineralising solution and incubated at
37 °C for 10 days. The CPP-ACP paste and the remineralising solution
were replaced every two days. Phosphorylated dentine slices without a
CPP-ACP application and non-phosphorylated dentine slices with a CPP-ACP
application were prepared and used for comparison. The slices were
examined using scanning electron microscope (SEM), diffuse
reflectance-Fourier transform infrared spectroscopy (DR-FTIR) and X-ray
diffraction (XRD).
Results
The
SEM results revealed the presence of intrafibrillar and interfibrillar
crystal nucleation and growth along the phosphorylated dentine collagen
fibres. The DR-FTIR and XRD confirmed that the crystals were
hydroxyapatite. No apatite crystal nucleation and growth were observed
in either the slices that had no non-phosphorylation or those without
CPP-ACP application.
Conclusions
CPP-ACP
can induce the biomimetic mineralisation of dentine through apatite
formation along and between the phosphorylated dentine collagen fibres.
Clinical significance
The in vitro
study imitated the application of CPP-ACP to exposed dentine tooth
surfaces in the mouth. This could lead to the development of a new
therapeutic technique for the treatment of tooth hypersensitivity.
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