Effect of water-ageing on dentine bond strength and anti-biofilm activity of bonding agent containing new monomer dimethylaminododecyl methacrylate
Available online 10 April 2013
Abstract
Objectives
The
objectives of this study were to develop bonding agent containing a new
antibacterial monomer dimethylaminododecyl methacrylate (DMADDM) as
well as nanoparticles of silver (NAg) and nanoparticles of amorphous
calcium phosphate (NACP), and to investigate the effects of water-ageing
for 6 months on dentine bond strength and anti-biofilm properties for
the first time.
Methods
Four
bonding agents were tested: Scotchbond Multi-Purpose (SBMP) Primer and
Adhesive control; SBMP + 5% DMADDM; SBMP + 5% DMADDM + 0.1% NAg; and
SBMP + 5% DMADDM + 0.1% NAg with 20% NACP in adhesive. Specimens were
water-aged for 1 d and 6 months at 37 °C. Then the dentine shear bond
strengths were measured. A dental plaque microcosm biofilm model was
used to inoculate bacteria on water-aged specimens and to measure
metabolic activity, colony-forming units (CFUs), and lactic acid
production.
Results
Dentine bond strength showed a 35% loss in 6 months of water-ageing for SBMP control (mean ± sd; n = 10);
in contrast, the new antibacterial bonding agents showed no strength
loss. The DMADDM–NAg–NACP containing bonding agent imparted a strong
antibacterial effect by greatly reducing biofilm viability, metabolic
activity and acid production. The biofilm CFU was reduced by more than
two orders of magnitude, compared to SBMP control. Furthermore, the
DMADDM–NAg–NACP bonding agent exhibited a long-term antibacterial
performance, with no significant difference between 1 d and 6 months (p > 0.1).
Conclusions
Incorporating
DMADDM–NAg–NACP in bonding agent yielded potent and long-lasting
antibacterial properties, and much stronger bond strength after 6 months
of water-ageing than a commercial control. The new antibacterial
bonding agent is promising to inhibit biofilms and caries at the
margins. The method of DMADDM–NAg–NACP incorporation may have a wide
applicability to other adhesives, cements and composites.
Comments