Biomedical Engineering Reference
In-Depth Information
(A)
(B)
(C)
(D)
(E)
FIGURE 20.4
SEM images of the enamel surfaces in different groups (60,000
). Many micropores and honeycomb
structures were apparently on enamel surface in DDW group (B), however, after application of nano-HA,
acicular crystals had sedimented on the lesion surface and the cavities and microspores significantly
decreased, meanwhile, the surface of the demineralized enamel appeared to be covered by crystal, arranged
in a thick and homogenous apatite layer (C). Some fingerlike crystals disorderly distributed on the surface of
enamel after being treated with GCE, a honeycomb structure still remained in some regions on the surface of
lesion (D). In GCE
3
nano-HA group, the surface morphology was similarly to that in the nano-HA group,
however, the crystals were arranged regularly and dense layer was also obtained after addition of GCE (E).
Different sized globules were formed on the lesion surface in the NaF group (A).
1
reservoir, helping to maintain a state of supersaturation with respect to enamel minerals, thereby
depressing enamel demineralization and enhancing remineralization; this is in accordance with the
classic paradigm of “top-down” ion-mediated crystalline growth to account for the intricate biomin-
eralization strategies identified in nature
[69]
. Nano-HA, however, shows promising remineraliza-
tion efficacy on enamel lesions in view of its unique characteristics, including excellent deposition
properties, which are in good agreement with the “bottom-up” concept of particle-mediated nano-
precursor assembly and mesocrystalline transformation in the biomineralization process
[70]
.
Other biomimetic approaches for remineralization of initial submicrometer enamel erosions and
lesions are based on nanosized casein phosphopeptide-amorphous calcium phosphate (CPP-ACP).
The CPP-ACP prevents demineralization and promotes remineralization of initial enamel lesions
in laboratory, animal, human experiments and in randomized, controlled clinical trials
[71
79]
.
