Development of a bimetallic zeolite for caries management

Abstract

Dental caries is a prevalent oral disease worldwide. It is caused by cariogenic microorganism, cariogenic diet, susceptible tooth surface, and time. Caries begins when cariogenic bacteria accumulate on the tooth surface and metabolize sugars to produce lactic acid, which causes tooth demineralization. Demineralization is the process of removing mineral ions (calcium and phosphate) from the hydroxyapatite crystals of the hard tissues of the tooth. Therefore, dental materials that inhibit the growth of cariogenic microorganisms and release calcium ions stably over time are considered to have potential for caries control.

Zeolites and zeolite imidazolate frameworks (ZIFs) are aluminum silicate crystals with porous structures that are widely used in the fields of industry, agriculture, food and medicine. Their enhanced ion exchange capacity, physicochemical stability, thermal stability and biocompatibility make them a promising dental material. Commonly used zeolite compounds for dentistry include silver zeolite, zinc zeolite, calcium zeolite and strontium zeolite. Commonly used ZIFs for dentistry include ZIF-8 and ZIF-67. Zeolites and ZIFs have been used in various fields of dentistry such as restorative dentistry, endodontics, prosthodontics, implantology, periodontics, orthodontics and oral surgery. Zeolites and ZIF can enhance the antimicrobial properties, mechanical properties, and stability of dental materials and can also be used as carriers for targeted drugs. Zeolites and zeolite imidazolate frameworks show great potential for application in clinical dental practice.

Based on the great potential of zeolites in dentistry, we synthesized a novel zeolite focused on caries management. We developed calcium silver zeolite using calcium chloride, silver nitrate and zeolite. We observed its morphological characterization, crystal structure, and evaluated its biocompatibility, calcium and silver ion release kinetics, and inhibition of common cariogenic bacteria. The calcium silver zeolite exhibits a hexagonal cage structure, possesses superior biocompatibility, releases calcium and silver ions in a sustained manner, and has antimicrobial properties.

Glass ionomer cement (GIC) is a multifunctional dental material mainly consists of calcium fluoro-aluminosilicate glass powder, and polyacrylic acid, which is widely used in caries treatment. Its advantages include fluoride-releasing properties, translucency, biocompatibility and good adhesion to dental tissues. However, it also has the disadvantages of low mechanical strength, poor abrasion resistance, limited antimicrobial effect and limited remineralization capacity. We have developed a novel GIC for caries management by adding calcium silver zeolite to GIC. We observed its surface morphology, and evaluated its biocompatibility, physical properties, antimicrobial effect, and ion release kinetics. The novel GIC containing calcium silver zeolite possessed superior biocompatibility. It presented better physical properties, antimicrobial effect, and calcium ion release compared to conventional GIC. (414 words)