Probing the neutralization behavior of zwitterionic monomer-containing dental adhesive

Abstract

Objective To investigate the polymerization kinetics, neutralization behavior, and mechanical properties of amine-functionalized dental adhesive cured in the presence of zwitterionic monomer, methacryloyloxyethyl phosphorylcholine (MPC). Methods The control adhesive was a mixture based on HEMA/BisGMA/2-N-morpholinoethyl methacrylate (MEMA) (40/30/30, w/w/w). The control and experimental formulations containing MPC were characterized with regard to water miscibility of liquid resins, photopolymerization kinetics, water sorption and solubility, dynamic mechanical properties and leachables from the polymers (aged in ethanol). The neutralization behavior of the adhesives was determined by monitoring the pH of lactic acid (LA) solution. Results The water miscibility decreased with increasing MPC amount. The water sorption of experimental copolymer specimen was greater than the control. The addition of 8 wt% water led to improved photo-polymerization efficiency for experimental formulations at MPC of 2.5 and 5 wt%, and significant reduction in the cumulative amounts of leached HEMA, BisGMA, and MEMA, i.e. 90, 60 and 50% reduction, respectively. The neutralization rate of MPC-containing adhesive was faster than control. The optimal MPC concentration in the formulations was 5 wt%. Conclusions Incompatibility between MEMA and MPC led to a decrease in water miscibility of the liquid resins. Water (at 8 wt%) in the MPC-containing formulations (2.5–5 wt% MPC) led to higher DC, faster RPmax and significant reduction in leached HEMA, BisGMA, and MEMA. The neutralization rate was enhanced with the addition of MPC in the amine-containing formulation. Promoting the neutralization capability of dentin adhesives could play an important role in reducing recurrent decay at the composite/tooth interface.

Fabrication of hybrid crosslinked network with buffering capabilities and autonomous strengthening characteristics for dental adhesives

“…In our previous study, amine-functionalized co-monomers have been introduced into the dental adhesive resin and the copolymers showed a long-term neutralization capacity [34,53,63,64]. In the present work, with the incorporation of amine functionalized poly-merizable component (SNM), the copolymers showed promising neutralization capacity, which could offer the benefit of maintaining the neutral pH at the localized micro-environment of the restorative material/tooth interface.…”

“…The protocol for determining water miscibility of adhesive formulations has been reported in detail [52,53]. In brief, about 0.5 g of each neat resin was weighed into a brown vial with water added in increments of approximately 0.005 g until the mixture was visually observed to be turbid.…”

Polybetaine-enhanced hybrid ionomer cement shows improved total biological effect with bacterial resistance and cellular stimulation

“…7 Previous studies have also explored the role of polybetaines in aiding the neutralization of bioactive resin formulations and have attributed it to enhanced ionic exchange from the bioactive filler. 32,33 In accordance, we investigated the cumulative ion-release and contrasted CTRL against the m ZM groups. Because it has reported previously there is an increase in elution at lower pH values (distilled water, ca.…”

“…7 Previous studies have also explored the role of polybetaines in aiding the neutralization of bioactive resin formulations and have attributed it to enhanced ionic exchange from the bioactive filler. 32,33 In accordance, we investigated the cumulative ion-release and…”

Bio-Interactive Zwitterionic Dental Biomaterials for Improving Biofilm Resistance: Characteristics and Applications

“…The use of MPC to augment pH neutralization of the dental adhesive was also reported in an in vitro setup [62]. This study tested the MPC concentrations of 2.5, 5, and 10 wt.%, as the amine monomer component of the resin adhesive, for assessment of the neutralization capacity and kinetics.…”