Related Experiment Video
Updated: Dec 22, 2025
Systematic Approach to Identify Novel Antimicrobial and Antibiofilm Molecules from Plants' Extracts and Fractions to Prevent Dental Caries
Published on: March 31, 2021
pH-responsive calcium and phosphate-ion releasing antibacterial sealants on carious enamel lesions in vitro
Maria Salem Ibrahim1, Abdulrahman A Balhaddad2, Isadora Martini Garcia3
1Ph.D. Program in Biomedical Sciences, Biomaterials and Tissue Engineering Division, University of Maryland School of Dentistry, Baltimore, MD, 21201, USA; Department of Preventive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.
Objective:
Nanoparticles of amorphous calcium phosphate (NACP) have shown beneficial effects of a robust release of calcium and phosphate ions at low pH. Here we examined the effect of NACP combined into antibacterial/rechargeable sealant formulations on the mineral content of artificial carious enamel during pH-cycling mimicking intraoral conditions.
Materials And Methods:
NACP and a quaternary ammonium methacrylate (DMAHDM) were synthesized. Three resin sealants were formulated: "base formulation" (without NACP and DMAHDM, used as control); "NACP on the base formulation" (with 20 wt.% NACP); "NACP on the antibacterial formulation" (with 20 wt.% NACP and 5 wt.% DMAHDM). Standardized enamel windows on sealed non-carious human molars were demineralized and randomly divided into four groups: three groups of teeth sealed with the experimental materials and one group of teeth without sealant application used as negative control. The teeth were exposed to pH cycling regime. The changes in the mineral content of enamel were assessed by quantitative surface hardness loss in percentage (%SHL) and qualitative analyses via scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM-EDX) and polarized light microscopy (PLM).
Results:
The contact with NACP-containing formulations provoked significant lower %SHL on sealed enamel (p < 0.05) in comparison to control groups. This outcome was supported by the results of SEM-EDX, in which the enamel presented higher percentages of calcium and phosphate than control groups. PLM showed less enamel superficial demineralization around the sealants containing NACP.
Conclusion:
NACP incorporated into an antibacterial sealant protected the enamel against demineralization. pH-responsive calcium and phosphate-ion releasing sealants with antimicrobial and rechargeable properties may be a reliable complementary approach for caries management.
Clinical Significance:
Dental caries is the most common childhood disease. Enamel demineralization represents the initial stage of carious lesion formation and may lead to invasive dental procedures. We explored the role of amorphous calcium phosphate (NACP) in a newly-developed antibacterial and rechargeable dental sealant formulation as a preventive approach.
