Low‐shrinkage‐stress nanocomposite: An insight into shrinkage stress, antibacterial, and ion release properties

Abstract

The aims are: (a) To develop the first low-shrinkage-stress nanocomposite with antibacterial and remineralization capabilities through the incorporation of dimethylaminododecyl methacrylate (DMAHDM) and nanoparticles of amorphous calcium phosphate (NACP); (b) to investigate the effects of the new composite on biofilm inhibition, mechanical properties, shrinkage stress, and calcium (Ca) and phosphate (P) ion releases. The low-shrinkage-stress resin consisted of urethane dimethacrylate and triethylene glycol divinylbenzyl ether. Composite was formulated with 3% DMAHDM and 20% NACP. Mechanical properties, shrinkage stress, and degree of conversion were evaluated. Streptococcus mutans biofilm growth on composites was assessed. Ca and P ion releases were measured. The shrinkage stress of the low-shrinkage-stress composite containing 3% DMAHDM and 20% NACP was 36% lower than that of traditional composite control (p < 0.05), with similar degrees of conversion of 73.9%. The new composite decreased the biofilm colony-forming unit by 4 log orders and substantially reduced biofilm lactic acid production compared to control composite (p < 0.05). Incorporating DMAHDM to the low-shrinkage-stress composite did not adversely affect the Ca and P ion release. A novel bioactive nanocomposite was developed with low shrinkage stress, strong antibiofilm activity, and high levels of ion release for remineralization, without undermining the mechanical properties and degree of conversion.

Low-Shrinkage Resin Matrices in Restorative Dentistry-Narrative Review

“…Moreover, the polymerization stress of the new composite was 40% lower than that of traditional composite control [111]. Also, the new composite has a strong antibiofilm activity that decreased the S.mutuns colonies to the minimum levels [112,113]. Another study conducted by Filemban et al concluded that the novel resin composite reduced the stress without compromising other properties, Figure 4.…”

“…The researchers developed a hydrolytically stable low-shrinkage-stress polymer containing UDMA and TEG-DVBE (U1V1). It was mixed with dimethylaminododecyl methacrylate monomer (DMAHDM)-with a carbon chain length of 16, which is a highly effective, contact-killing, long-lasting antibacterial material [110][111][112][113][114]. Moreover, adding bioactive nanoparticles of amorphous calcium phosphate (NACP) was advantageous to dental tissues to regenerate the lost minerals and buffer the acidic environment by releasing calcium and phosphate ions to the enamel and dentin under low pH conditions [110][111][112][113][114].…”

Novel Dental Low-Shrinkage-Stress Composite with Antibacterial Dimethylaminododecyl Methacrylate Monomer

“…The low-shrinkage-stress (LSS) resin was formulated using 55.8% UDMA (Esstech, Essington, PA, USA) and 44.2% TEG-DVBE (mass %), following previous studies [30,34]. This resin was designated as "UV".…”

“…In this study, Heliomolar (Ivoclar, Ontario, Canada) was used as a commercial control. It is a bioactive material that has the ability to release fluoride, according to previous studies [23,34]. The objective of this study was to investigate the antimicrobial efficacy and mechanical properties of the new formulations.…”

“…For mechanical testing, a mold with specific dimensions of 2 × 2 × 25 mm 3 was used to produce the composite bars [34]. Specimens were photopolymerized using a Labolight, DUO (GC, Tokyo, Japan) curing lamp for 1 min [34].…”