Physical/mechanical and antibacterial properties of orthodontic adhesives containing Sr-bioactive glass nanoparticles, calcium phosphate, and andrographolide

Abstract

White spot lesions around orthodontic brackets are the major complication during fixed orthodontic treatment. This study prepared orthodontic adhesives for promoting mineral precipitation and reducing bacterial growth. Adhesives with added calcium phosphate monohydrate/Sr-bioactive glass nanoparticles (Sr/CaP) and andrographolide were prepared. The physical/mechanical and antibacterial properties of the adhesives were tested. The additives reduced the monomer conversion of the materials (62 to 47%). The addition of Sr/CaP and andrographolide increased the water sorption (from 23 to 46 μg/mm3) and water solubility (from 0.2 to 5.9 μg/mm3) but reduced the biaxial flexural strength (from 193 to 119 MPa) of the adhesives. The enamel bond strengths of the experimental adhesives (19–34 MPa) were comparable to that of the commercial material (p > 0.05). The Sr/CaP fillers promoted Ca, Sr, and P ion release and the precipitation of calcium phosphate at the debonded interface. An increase in the Sr/CaP concentration enhanced the inhibition of S. mutans by 18%, while the effect of andrographolide was not detected. The abilities of the adhesives to promote ion release, calcium phosphate precipitation, and the growth inhibition of cariogenic bacteria were expected to reduce the occurrence of white spot lesions. The additives reduced the physical/mechanical properties of the materials, but the corresponding values were within the acceptable range.

Adhesive Bond Integrity of Experimental Zinc Oxide Nanoparticles Incorporated Dentin Adhesive: An SEM, EDX, μTBS, and Rheometric Analysis

“…Incorporation of nanoparticle fillers in polymeric adhesives has shown increase of the adhesive's bond strength and a decline in DC in previous studies [ 24 , 49 ]. A possible explanation for decrease in DC on incorporation of ZnO particles is a reduction in curing light penetration through the adhesive medium for monomer to polymer conversion, thereby resulting in a loss of DC [ 50 ].…”

Effects of Sr/F-Bioactive Glass Nanoparticles and Calcium Phosphate on Monomer Conversion, Biaxial Flexural Strength, Surface Microhardness, Mass/Volume Changes, and Color Stability of Dual-Cured Dental Composites for Core Build-Up Materials

“…It was reported that bioactive glass nanoparticles and calcium phosphates promoted ion release that could potentially enhance remineralizing actions and prevent dental caries [ 8 , 10 , 14 , 15 ]. However, the additives were hydrophilic and non-silanized, which may inevitably reduce the physical/mechanical properties of the composites.…”

“… where F is failure load (N), d represents the thickness of disc specimens (m), r is the radius of circular support of the ball-on-ring jig (m), and v is Poisson’s ratio (0.3). Furthermore, represents the rate of change of the load about the central deflection or gradient of force versus the displacement curve (N/m) [ 15 ]. Additionally, and q represents the center deflection junction (0.5024) and the ratio of the support radius to the specimen radius, respectively.…”

“…Bioactive glass nanoparticles represent an alternative ion-releasing filler [ 11 ]. Several studies have incorporated sol-gel-derived bioactive glass nanoparticles into resin composites to enable ion releasing or antibacterial actions for the materials [ 12 , 13 , 14 , 15 ]. Additionally, it was reported that the addition of bioactive glass nanoparticles exhibited no significant effects on the mechanical strength of the composites [ 16 , 17 , 18 ].…”

Evaluation of the effectiveness of bioactive glass fillers against Candida albicans adhesion to PMMA denture base materials: An in vitro study

“…In a study was done by Waltimo et al, (2007) where they used BAG (amorphous nanoparticles, 20- to 60-nm size) to look into its antimicrobial efficacy and had showed an antimicrobial ability which helped to the continuous liberation of alkaline species. Recently, Chaichana et al (2022 ) deduced the ability if ion release and inhibition of the growth of cariogenic bacteria upon the addition of BAG to orthodontic adhesive. However, the effectiveness of its antifungal properties in denture base material is yet to be investigated.…”