Novel self-etch adhesive with antibacterial and protein-repellent functions to prevent enamel demineralization

Abstract

Enamel demineralization is the most undesired side-effect of fixed orthodontic treatments. This study were to develop a novel adhesive that is self-etching instead of using the traditional etching method, and to form a sealant on the enamel to prevent demineralization. 2-methacryloyloxyethyl phosphorylcholine (MPC) and quaternary ammonium dimethylaminohexadecyl methacrylate (DMAHDM) were mixed into a self-etch adhesive (Adper Easy One, 3M, St. Paul, MN, USA; referred to as AEO). Enamel shear bond strength (SBS) was measured. Protein adsorption onto the resins was measured. An oral microcosm biofilm model with saliva was tested. Incorporation of 7.5% MPC and 5% DMAHDM into AEO did not reduce the SBS (p>0.1). AEO with 7.5% MPC+5% DMAHDM had protein adsorption that was only 1/18 that of AEO control. AEO with 7.5% MPC+5% DAMHDM had much stronger antibacterial properties (p<0.05). In conclusion, the new self-etch adhesive with MPC and DAMHDM greatly reduced protein adsorption and inhibited biofilm viability.

Novel Protein-Repellent and Antibacterial Resins and Cements to Inhibit Lesions and Protect Teeth

“…Reynolds et al [66] suggested that the appropriate shear bonding strength for orthodontic cements was approximately 8 to 9 MPa, which was high enough to prevent the brackets from falling off the surface of the teeth, while avoiding enamel damage during the debonding process at the completion of the orthodontic treatment. The results of Wang et al [63] showed that the enamel shear bond strength of the self-etch group containing MPC and DMAHDM was 9-10 MPa, which is clinically acceptable. Their research suggested that adding MPC and DMAHDM into the self-etch adhesive exhibited excellent antibacterial and proteinrepellent effect without compromising the bond strength of the brackets.…”

“…Adding either 5% DMAHDM or 7.5% MPC alone into AEO reduced the metabolic activity to nearly 17% and 33% of that of AEO control, respectively. More dramatically, biofilms on the adhesive containing both 7.5% MPC and 5% DMAHDM together had the lowest metabolic activity, which was only 5% of that of AEO control (Figure 6(b)) [63].…”

“…Based on these results, Wang et al [63] suggested that there was a synergistic effect of MPC and DMAHDM in the adhesive on antibiofilm properties. Quaternary ammonium compounds, which were positively charged, could bind to the negatively charged cell wall components, cause the leakage of the cytoplasmatic material, and finally lead to the lysis of the bacterial cells [31].…”

“…In a previous study, Wang et al [63] mixed MPC and DMAHDM into a self-etch adhesive (Adper Easy One, 3 M, St. Paul, MN, USA; referred to as AEO) to repel protein adsorption and decrease bacteria accumulation. In their study, the self-etch adhesive with 7.5% MPC had much less bacterial attachment and reduced the protein adsorption to only 5% that of control ( Figure 6(a)).…”

“…Values with dissimilar letters are significantly different from each other (p < 0 05). (Adapted from reference[63], with permission).…”