Effect of Indigenously Developed Nano-Hydroxyapatite Crystals from Chicken Egg Shell on the Surface Hardness of Bleached Human Enamel

Abstract

Objective: The objective was to evaluate the effect of nano-hydroxyapatite (nHA) derived from chicken eggshell on bleached human enamel in comparison with commercial casein phophopeptide-amorphous calcium phosphate (CPP-ACP) paste using Vickers microhardness test. Materials and Methods: nHA powder was prepared from chicken eggshell using combustion method. nHA slurry was prepared by mixing 1.8 g of nHA powder with 0.3 ml of distilled water. Forty intact maxillary anterior teeth were collected and decoronated, and the crowns were embedded in acrylic mold with the labial enamel surfaces exposed. Baseline microhardness evaluation was done (T0). The specimens were randomly divided into the following four groups (n = 10) based on the surface treatment of enamel: Group 1: no bleaching treatment; Group 2: bleaching with 30% hydrogen peroxide (HP) solution; Group 3: bleaching followed by the application of CPP-ACP; and Group 4: bleaching followed by the application of nHA. The specimens were stored in artificial saliva at 37°C for 2 weeks, after which they were subjected to Vickers microhardness test (T14). One-way ANOVA and Tukey's post hoc multiple comparison tests were used for statistical analysis (P < 0.05). Results: Bleaching with HP significantly decreased the enamel microhardness. CPP-ACP and nHA derived from chicken eggshell increased the enamel microhardness significantly. There was no significant difference in microhardness values among the CPP-ACP and nHA groups. Conclusion: Nano-hydroxyapatite sourced from chicken eggshell was as effective as CPP-ACP in remineralizing and restoring the lost microhardness of bleached enamel.

Effect of eggshell powder and nano-hydroxyapatite on the surface roughness and microhardness of bleached enamel

“…Kunam et al . [ 25 ] supported our findings. They reported that nHA showed a significant elevation on the surface enamel microhardness.…”

Remineralization effect of calcium glycerophosphate in fluoride mouth rinse on eroded human enamel: An in vitro study

“…These differences could be related to differences in specimen preparation methods, the degree of enamel mineralization, or local variations resulting from enamel rods and tufts. [ 20 ] However, there were no significant differences in the mean SMH value among the groups at Baseline.…”

Eggshell-Waste-Derived Calcium Acetate, Calcium Hydrogen Phosphate and Corresponding Eggshell Membranes

“…Numerous reports deal with the transformation of ESW using o-phosphoric acid [2,8,10,13,[27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43]55], but the possibility of the production of calcium hydrogen phosphate from ESW has been reported by only one scientific report [42] and one patent [56]. Laohavisuti et al [42] prepared calcium hydrogen phosphate of high purity/yield of 99.63% using ESW, which is much higher than the mass yield observed in our research (77.06 ± 6.21%), but authors used an ESW calcination at 500 • C for two hours where all organic matter was incinerated, and a much greater o-phosphoric concentration (50%) for the solvation of ESW calcium carbonate.…”

“…In continuation of our efforts oriented toward the complete utilization of ESW, in our present research, we have examined the possibility of chemical transformation of ESW with acetic and o-phosphoric acid to the corresponding calcium salts and eggshell membranes. Although the use of o-phosphoric and acetic acid for the production of corresponding Ca-salts from eggshell waste, such as calcium hydroxyapatite [2,8,10,13,[27][28][29][30][31][32][33][34][35][36][37][38][39], calcium triphosphate [13,28,[30][31][32]34,38,[40][41][42], calcium diphosphate [42,43] and much less studied calcium monophosphate [42] or calcium acetate [44,45], have been reported, the novelty of our research lies in the use of eggshell halves and pieces In this respect, our research group has been oriented towards the possibility of the complete utilization of eggshell waste, using the most common industrial processes, such as mixing, filtration, evaporation and drying, but with the aim of producing high-value-added products. Our most recent publication [1] has proven the possibility of ESW utilization for the production of egg white protein solution, calcium chloride dihydrate as a food-grade additive, and eggshell membranes, using ESW transformation with 5% (w/v) hydrochloric acid.…”

“…In continuation of our efforts oriented toward the complete utilization of ESW, in our present research, we have examined the possibility of chemical transformation of ESW with acetic and o-phosphoric acid to the corresponding calcium salts and eggshell membranes. Although the use of o-phosphoric and acetic acid for the production of corresponding Ca-salts from eggshell waste, such as calcium hydroxyapatite [2,8,10,13,[27][28][29][30][31][32][33][34][35][36][37][38][39], calcium triphosphate [13,28,[30][31][32]34,38,[40][41][42], calcium diphosphate [42,43] and much less studied calcium monophosphate [42] or calcium acetate [44,45], have been reported, the novelty of our research lies in the use of eggshell halves and pieces instead of milled ones, the chemical transformation of eggshell waste calcium carbonate with diluted acids instead of those with higher percentages, the use of room temperature during the ESW chemical transformation into salt solutions and ESMs instead of higher ones, as well as the production of calcium salts as the major product and corresponding eggshell membranes as valuable by-products. Moreover, ESW-derived calcium acetate monohydrate and calcium hydrogen phosphate obtained in this research were fully examined in the prescribed demands regarding their suitability as food-grade additives.…”