A novel air-polishing powder from natural eggshell

Area of Science:

• Dental materials science
• Surface chemistry
• Biomaterials engineering

Background:

• Dental air polishing is a common method for extrinsic stain removal.
• Traditional air polishing powders, such as sodium bicarbonate, can alter tooth surface properties.
• Novel biomaterials are being explored as alternatives for dental applications.

Purpose of the Study:

• To compare the extrinsic stain removal efficacy of sodium bicarbonate powder and a novel eggshell powder.
• To evaluate the impact of these powders on tooth surface roughness.

Main Methods:

• Extrinsic stains were created on bovine teeth by coffee immersion.
• Tooth color change (ΔE*) was measured using a colorimeter after polishing.
• Surface roughness (S_a) was measured using a contact-type profilometer on human posterior teeth before and after polishing.

Main Results:

• Sodium bicarbonate powder exhibited significantly higher stain removal (ΔE*) than eggshell powder (P < 0.05).
• Sodium bicarbonate powder also caused significantly greater surface roughness changes (ΔS_a) compared to eggshell powder (P < 0.05).

Conclusions:

• Sodium bicarbonate powder is more effective for extrinsic stain removal.
• The use of sodium bicarbonate powder leads to more pronounced changes in tooth surface roughness.
• Eggshell powder presents a potentially gentler alternative for air polishing, though with lower stain removal efficacy.