Biomimetic remineralization of enamel and dentin with chicken eggshell slurry: An in vitro study

In the light of escalating focus on preventive and minimally invasive dental practices, this study explores the potential of chicken eggshell powder (CESP) as an eco-friendly source of calcium and bioactive compounds for remineralization of demineralized dental substrates.

The aims of this study were to characterize and evaluate the remineralization potential of CESP slurry on demineralized human permanent teeth.

CESP was prepared from chicken eggshell using calcination procedure followed which CESP slurry was prepared. The CESP powder was characterized using Fourier transform infrared spectroscopy (FTIR) analysis. Twenty-four intact human third molars were collected and sectioned, randomly allocated into two groups (n = 96): G1 - enamel (E) and G2 - dentin (D) which were further divided into the following six subgroups (n = 16) based on the intended surface treatment: E1 (sound enamel-control), E2 (demineralized enamel with no treatment), and E3 (enamel treated with CESP), D1 (sound dentin-control), D2 (demineralized dentin with no treatment), and D3 (dentin treated with CESP). All enamel and dentin blocks except those in Group E1 and D1 were immersed in a demineralizing solution for 72 h. E3 and D3 were subjected to the application of CESP slurry twice daily for a week by gentle rubbing for 2 min. All samples underwent pH-cycling and were tested using a Vickers hardness tester and scanning electron microscopy analysis.

Tukey's honestly significant difference test and paired samples test were used for statistical analysis (P < 0.005).

FTIR analysis of CESP revealed notable peaks in the range of 1400-1500 cm^-1 and sharp peaks around 1000-700 cm^-1, a feature commonly observed in calcium carbonate. A significantly higher mean % recovery of surface microhardness (%RSMH) was seen as compared to the mean % decrease in surface microhardness (%DSMH) in enamel with a mean difference ofcm-13.32 ± 4.0 (P = 0.000), whereas, in the case of dentin, a significantly higher mean % DSMH was seen as compared to mean % RSMH with a mean difference of 61.47 ± 3.7 (P = 0.000).

The elevated pH of the chicken eggshell solution, coupled with the abundant bioavailable calcium content, holds the potential to favor remineralization. The findings suggest that the application of CESP slurry could contribute to the remineralization process.