Hydroxyapatite-based cavitary varnish derived from eggshells: An in vitro analysis of dentin surface

Area of Science:

• Biomaterials Science
• Dental Materials
• Nanotechnology

Background:

• Dentin hypersensitivity is a common clinical condition.
• Hydroxyapatite (HA) is a key component of tooth structure and has shown potential in dentin remineralization.
• Developing effective and sustainable biomaterials for dentin repair is crucial.

Purpose of the Study:

• To evaluate the effectiveness of a novel cavitary varnish containing experimental eggshell-derived hydroxyapatite (HA) on dentin surfaces.
• To assess the impact of simulated brushing on the properties of the HA varnish.

Main Methods:

• Bovine dentin samples were treated with distilled water, cavitary varnish, a commercial product, commercial HA nanoparticles, or the experimental HA varnish.
• Samples underwent simulated brushing.
• Evaluations included surface roughness, morphology (SEM), chemical composition, dentinal tubule diameter, and hydraulic conductance (permeability).
• Statistical analysis was performed using two-way ANOVA with Bonferroni post-hoc tests.

Main Results:

• The experimental HA varnish achieved complete and persistent dentinal tubule occlusion, even after brushing.
• Dentin permeability (hydraulic conductance) was significantly reduced by the HA varnish, comparable to commercial products.
• Scanning electron microscopy confirmed tubule occlusion, and chemical analysis showed HA's influence on calcium and phosphorus levels.

Conclusions:

• Eggshell-derived HA in a cavitary varnish effectively occludes dentinal tubules and reduces dentin permeability.
• The observed effects were persistent after simulated brushing, highlighting the material's durability.
• This experimental HA represents a promising, sustainable, and cost-effective biomaterial for dental applications.