An investigation in the remineralization and acid resistant characteristics of nanohydroxyapatite produced from eggshell waste via mechanochemistry

Abstract

Objectives: This study focuses on the properties of nanohydroxyapatite (nHAp) in terms of remineralization and acid resistance. The nHAp were produced from waste eggshells via the mechanochemistry process. Materials and methods: The characterization was based on Fourier Transform Spectroscopy, X-ray diffraction, Field Scanning Electron Microscope (FESEM), and High-Resolution Electron Microscope to determine the surface morphology of the nHAp. The acid and remineralization properties were evaluated using bovine enamel and dentine models ( n = 5) while the buffering properties against acids were studied using a pH meter. The biocompatibility of the produce nHAp was assessed in vitro against NIH 3T3. Results: The XRD and FTIR results confirm that nHAp were successfully produced from eggshell waste after 5 h of milling. The HRTEM reveals a semi-sphere morphology with an average dimension of 9 to 20 nm. The buffering test suggests that nHAp were highly effective in neutralizing common dietary acids. Also, the nHAp exhibits outstanding remineralization and occluding properties. The cytotoxicity assay suggests that the nHAp had a low toxicity. Conclusion: The study concludes that using eggshell waste to produce nHAp will help in waste management and at the same time, provide valuable biomaterial for the treatment of tooth sensitivity.

An In Vitro Assessment of the Acid Resistance Characteristics of Nanohydroxyapatite/Silica Biocomposite Synthesized Using Mechanochemistry

“…The sharp spectrum around 3750 cm −1 is attributed to the OH stretching [19]. The absorption bands of carbonates (CO 3 2− ions) in the hydroxyapatite structure were observed around 1450 cm −1 [7,18]. On the contrary, the image in Figure 1(c) reveals the presence of Si-O-Si stretching.…”

“…In Figure 1(a), the spectrum observed around 1000 cm −1 is attributed to the P-O asymmetrical in the hydroxyapatite [19]. The broad spectrum observed around 3450 cm −1 and 3000 cm −1 and a sharp peak at 1600 cm −1 was attributed to water molecules [7,18,20]. The sharp spectrum around 3750 cm −1 is attributed to the OH stretching [19].…”

“…The powder obtained after milling was characterized to establish the formation of nHAp in the first step and the subsequent modification with silica in the second step. The particle size and shape of the prepared nHAp are reported in another study [18]. The pH of the samples was measured using a pH meter.…”

“…In line with the procedure demonstrated by Onwubu et al [18], bovine tooth enamel was used to assess the acid resistance characteristics of the samples. The tooth enamel specimens were assigned randomly into five groups (n = 5).…”

“…Owing to this, a novel approach in the treatment and management of DH is the use of various nanomaterials [4,5]. Among these materials, mesoporous silica (MSN) and nanohydroxyapatite (nHAp) had gained enormous research interest due to their antibacterial action; physical, mechanical, and biological characteristics; and distinctive particle size [6,7].…”