Nanosized calcium deficient hydroxyapatites for tooth enamel protection

Area of Science:

• Materials Science
• Biomaterials
• Dental Materials

Background:

• Calcium phosphates (CaP) are vital for tooth enamel protection against caries.
• The potential of substituted CaP for enhanced enamel protection remains unclear.

Purpose of the Study:

• To synthesize and characterize strontium (Sr2+) and fluoride (F-) substituted calcium deficient hydroxyapatite (CDHAp).
• To evaluate the in vitro efficacy of substituted CDHAp in promoting enamel remineralization and pH increase.

Main Methods:

• X-ray powder diffractometry, FTIR, SEM, EDX, BET for material characterization.
• Cytotoxicity evaluation and pH-time profile analysis.
• In vitro remineralization assays on bovine enamel using profilometry.

Main Results:

• Successfully synthesized CDHAp with 1.5-1.6 wt% F- and 7.4-7.8 wt% Sr2+.
• CDHAp suspensions increased media pH by ~0.3 within 10 min after acid addition.
• A protective CDHAp layer (up to 5.8 μm in 7 days) formed on enamel, with no significant differences among tested groups.

Conclusions:

• CDHAp substituted with Sr2+ and/or F- can form a protective layer on enamel.
• These substituted CDHAp show potential as additives in dental care products for enamel protection.
• No significant difference in protective efficacy was observed among the different substituted CDHAp groups.