The remineralization properties of two newly developed orthodontic primers

This study aimed to explore the demineralization resistance and remineralization effects of the two newly modulated orthodontic primers and to compare them with those of the Transbond™ XT orthodontic primer.

After preparation of graphene oxide/hydroxyapatite (GOHA) and graphite fluoride/bioactive glass (GFBAG) primers, they were evaluated by Field Emission Scanning Electron Microscope (FESEM) and Energy Dispersive X-ray spectroscopy (EDX). The remineralization properties were evaluated through the assessment of calcium (Ca) and phosphate (PO₄) ions released from primer disks (n = 10) for 168 days, the demineralization resistance was explored by evaluating the flat surface of molar teeth (n = 6) by Raman spectroscopy, and the length of the anti-demineralization zone around orthodontic bracket was measured by micro-CT analysis of premolar teeth (n = 5) bonded with one of the experimental or control primers.

Both primers showed a homogenous distribution with the presence of Ca in both primers and Fluorine (F) in the GFBAG. High levels of Ca and PO₄ ions were reported until the 112th day for the GOHA primer and the 168th day for the GFBAG primer. The result of Raman spectroscopy revealed the maintenance of mineral content with the GFBAG primer, followed by the GOHA primer, after subjecting the teeth to pH cycling to develop WSLs. The micro-CT analysis revealed a significant increase in the anti-demineralization length in both experimental primers compared to the control primer (p < 0.05).

The results of the current study collectively illustrate the improvement of the remineralization properties with GOHA and GFBAG primers, with some priority to the GFBAG primer.