In vitro study on the neutralization potential of particulate hydroxyapatite in erosive acids

Area of Science:

• Biomaterials Science
• Dental Materials Science
• Nanotechnology

Background:

• Hydroxyapatite (HAP) is a key component in oral care, acting as a remineralizing agent and ion reservoir.
• HAP's ability to neutralize acids makes it crucial for combating dental erosion and caries.

Purpose of the Study:

• To evaluate the acid neutralization capacity of HAP particles in oral care formulations.
• To investigate the impact of HAP on pH, calcium ion (Ca2+) release, and structural integrity under acidic conditions.

Main Methods:

• In vitro assessment of HAP's neutralization potential in various acids and beverages.
• Measurement of pH changes, Ca2+ release via Atomic Absorption Spectroscopy (AAS).
• Analysis of HAP morphology and composition using Scanning Electron Microscopy (SEM) and X-ray Powder Diffraction (XRD).

Main Results:

• HAP significantly increased pH across all tested acidic systems, neutralizing 98.0%–99.9% of protons.
• Substantial Ca2+ release (up to 2619 mg L−1) was observed, particularly in hydrochloric acid, without compromising HAP structure.
• Even low concentrations (0.15% w/v) of HAP rapidly neutralized acids in beverages within seconds.

Conclusions:

• HAP demonstrates potent acid-neutralizing capabilities essential for oral care applications.
• The release of Ca2+ ions and maintained structural integrity highlight HAP's efficacy.
• HAP effectively counteracts acid challenges, supporting its role in dental health products.