In vitro Evaluation of Dentine Remineralisation by a Self-assembling Peptide using Scanning Electron Microscopy

A biomimetic self-assembling peptide was recently introduced as a non-invasive treatment for early stage dental caries. The self-assembling peptides can diffuse into the subsurface micro-pores and form a 3D scaffold mimicking the proteins’ function during tooth development to support apatite crystallisation, promote remineralisation and reverse early tooth decay. The present study’s aim was to investigate the ability of a commercially available biomimetic self-assembling peptides in promoting mineralisation on a dentine surface. Dentine discs were polished and etched with 6% citric acid for 2 minutes. Each disc was halved, one for treatment with the self-assembling peptides and one as a control. Both halves were quartered as paired samples, and subjected to immersion in TRIS buffer (pH=7.35) or artificial saliva (AS, pH=6.5) for different time periods. The samples were further fractured for Scanning Electron Microscopy analysis on the etched and fracture surfaces. The controls exhibited open dentine tubules with a size between 2.3-4.2 µm in diameter and the fracture surfaces exhibited a characteristic funnel-shape of the open etched tubules with an etched smooth surface. No visible changes were observed for both the control and peptide treated dentine discs following immersion in TRIS. Similar results were observed for the controls immersed in AS. In contrast, plate-like structures present in, on and around the dentine tubules were clearly visible in samples treated with the self-assembling peptides following 3 hours immersion in AS. The fracture surface demonstrated that the plate-like structures interacted with the smooth etched dentine surface. Occlusion of the dentine tubules with Calcium Phosphate was also evident. The biomimetic self-assembling peptides clearly promoted apatite formation compared with the controls and allowed the interaction between an apatite-like phase and the etched smooth dentine surface.