Novel rechargeable calcium phosphate dental nanocomposite

Abstract

Objectives Calcium phosphate (CaP) composites with Ca and P ion release can remineralize tooth lesions and inhibit caries. But the ion release lasts only a few months. The objectives of this study were to develop rechargeable CaP dental composite for the first time, and investigate the Ca and P recharge and re-release of composites with nanoparticles of amorphous calcium phosphate (NACP) to achieve long-term inhibition of caries. Methods Three NACP nanocomposites were fabricated with resin matrix of: (1) bisphenol A glycidyl dimethacrylate (BisGMA) and triethylene glycol dimethacrylate (TEGDMA) at 1:1 mass ratio (referred to as BT group); (2) pyromellitic glycerol dimethacrylate (PMGDM) and ethoxylated bisphenol A dimethacrylate (EBPADMA) at 1:1 ratio (PE group); (3) BisGMA, TEGDMA, and Bis[2-(methacryloyloxy)ethyl] phosphate (BisMEP) at 2:1:1 ratio (BTM group). Each resin was filled with 20% NACP and 50% glass particles, and the composite was photo-cured. Specimens were tested for flexural strength and elastic modulus, Ca and P ion release, and Ca and P ion recharge and re-release. Results NACP nanocomposites had strengths 3-fold of, and elastic moduli similar to, commercial resin-modified glass ionomer controls. CaP ion recharge capability was the greatest for PE group, followed by BTM group, with BT group being the lowest (p < 0.05). For each recharge cycle, CaP re-release reached similarly high levels, showing that CaP re-release did not decrease with more recharge cycles. After six recharge/re-release cycles, NACP nanocomposites without further recharge had continuous CaP ion release for 42 d. Significance Novel rechargeable CaP composites achieved long-term and sustained Ca and P ion release. Rechargeable NACP nanocomposite is promising for caries-inhibiting restorations, and the Ca and P ion recharge and re-release method has wide applicability to dental composites, adhesives, cements and sealants to achieve long-term caries-inhibition.

Protein-repellent and antibacterial functions of a calcium phosphate rechargeable nanocomposite

“…A new rechargeable NACP composite with multiple recharge/re-release capability was recently developed for long-term caries-inhibition [30,31]. However, CaP composites are not antibacterial.…”

“…CaP composite was developed with long-term Ca and P ion release for the first time [30,31]. Its Ca and P ion recharge and re-release were sustained, showing no decrease with increasing the recharge/re-release cycles [30,31].…”

“…Recently, a rechargeable CaP composite was developed with long-term Ca and P ion release for the first time [30,31]. Its Ca and P ion recharge and re-release were sustained, showing no decrease with increasing the recharge/re-release cycles [30,31]. However, while CaP composites have remineralization and acid neutralizing capabilities, they do not have significant antibacterial activity.…”

“…Third, PMGDM is an acidic adhesive monomer with a carboxylate group, hence EBPM can chelate with calcium ions from the exterior environment such as a recharge solution [31,37,61]. EBPM-NACP composite could repeatedly recharge Ca and P ions into the composite to have long-term ion re-release [30,31]. Therefore, all three bioactive mechanisms (MPC, DMAHDM, and NACP) of the composite are expected to have long-term durability.…”

Bioactive Dental Composites and Bonding Agents Having Remineralizing and Antibacterial Characteristics

“…Recently, an experimental rechargeable CaP dental composite was developed [40]. Three NACP nanocomposites were tested using resins including:

bisphenol A glycidyl dimethacrylate (BisGMA) and triethylene glycol dimethacrylate (TEGDMA) (referred to as BT group);

pyromellitic glycerol dimethacrylate (PMGDM) and ethoxylated bisphenol A dimethacrylate (EBPADMA) (referred to as PE group);

BisGMA, TEGDMA, and Bis[2-(methacryloyloxy)ethyl] phosphate (BisMEP) (referred to as BTM group).

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