Characterization of the effects of 3DSS peptide on remineralized enamel in artificial saliva

Aspartate–serine–serine (DSS) repeats are abundant in naturally occurring proteins that are critical for tooth formation. In this study, we reported a possible role of triplet repeats of aspartate–serine–serine (3DSS) peptides in promoting mineral deposition onto human enamel from free ions. Human enamel specimens were acid demineralized, exposed briefly to 3DSS peptide solution, and then immersed in artificial saliva. At various stages of treatments, nanomechanical behaviors, surface morphology, surface roughness and the sorts of deposited minerals were characterized by nanoindentation, scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD), respectively. The results indicated that treatment with 3DSS peptide promoted the uniform deposition of apatites with small crystalline size, in terms of prohibiting deformation, which resulted in a smaller average surface roughness and higher average values of nanohardness and elastic modulus of demineralized enamel treated with 33.3 μM 3DSS peptide and immersed in artificial saliva compared to that without peptide treatment.