Effect of a Novel Quaternary Ammonium Methacrylate Polymer (QAMP) on Adhesion and Antibacterial Properties of Dental Adhesives

Abstract

This study investigated the resin–dentin bond strength (μTBS), degree of conversion (DC), and antibacterial potential of an innovative adhesive system containing a quaternary ammonium methacrylate polymer (QAMP) using in situ and in vitro assays. Forty-two human third molars were flattened until the dentin was exposed and were randomly distributed into three groups of self-etching adhesive systems: Clearfil™ SE Bond containing 5% QAMP (experimental group), Clearfil™ Protect Bond (positive control) and Clearfil™ SE Bond (negative control). After light curing, three 1 mm-increments of composite resin were bonded to each dentin surface. A total of thirty of these bonded teeth (10 teeth per group) was sectioned to obtain stick-shaped specimens and tested under tensile stress immediately, and after 6 and 12 months of storage in distilled water. Twelve bonded teeth (4 teeth per group) were longitudinally sectioned in a mesio-to-distal direction to obtain resin-bonded dentin slabs. In situ DC was evaluated by micro-Raman spectroscopy. In vitro DC of thin films of each adhesive system was measured using Fourier transform infrared spectroscopy. In vitro susceptibility tests of these three adhesive systems were performed by the minimum inhibitory/minimum bactericidal concentration (MIC/MBC) assays against Streptococcus mutans, Lactobacillus casei, and Actinomyces naeslundii. No statistically significant difference in μTBS was observed between Clearfil™ SE Bond containing 5% QAMP and Clearfil™ SE Bond (p > 0.05) immediately, and after 6 and 12 months of water storage. However Clearfil™ Protect Bond showed a significant reduction of μTBS after 12 months of storage (p = 0.039). In addition, QAMP provided no significant change in DC after incorporating into Clearfil™ SE Bond (p > 0.05). Clearfil™ SE Bond containing 5% QAMP demonstrated MIC/MBC values similar to the positive control against L. casei and A. naeslundii and higher than the negative control for all evaluated bacterial strains. The use of QAMP in an adhesive system demonstrated effective bond strength, a suitable degree of conversion, and adequate antibacterial effects against oral bacteria, and may be useful as a new approach to provide long-lasting results for dental adhesives.

Effect on vascular permeability of a self-etching adhesive system containing an antimicrobial quaternary ammonium polymer QAMP into subcutaneous tissue of rats

“…6,27,28 In a previous paper devoted to investigate the QAMP behaviour in dental adhesive systems, this quaternary ammonium polymer demonstrated a lower migration from the adhesive system compared to MDPB due to its high molecular weight. 6,33 Furthermore, a commercial adhesive containing QAMP (Clearfil TM SE Bond containing 5% QAMP) showed statistically similar degree of conversion than Clearfil TM Protect Bond and Clearfil TM SE Bond by in situ and in vitro analyses. 33 Thus, the main result of this paper is that QAMP incorporation did not adversely influence the exudative phase of inflammatory process which can be deeply related to the previously reported data that showed an effective lightcuring of the adhesive system containing QAMP and a low release of quaternary ammonium compounds from this dental material.…”

Quaternary ammonium compounds in dental restorative materials

“…Generally speaking, however, with the increase of the amount of antibacterial agent, the mechanical properties and biocompatibility of the material will decrease. QACs belong to a kind of nonrelease antibacterial agent, and the antibacterial effect can be achieved when the dosage is relatively large 32,[44][45][46][47] . While the release antimicrobial agents can achieve better antibacterial effect at a low concentration, however, their extending antibacterial efficiency is low and they may be more toxic toward surrounding environments, the so-called "sudden release effect" [104][105][106][107] .…”

“…Meanwhile, 5 wt% DMADDM was incorporated into Clearfil SE Bond by Zhang et al It had been observed that adhesives containing DMADDM inhibited the growth, lactic acid production, and Exopolysaccharides (EPS) metabolism of S. mutans biofilm at different stages, with no adverse effect on its dentin adhesive bond strength 44,45) . Besides that, Pupo et al 46,47) performed a study incorporating of quaternary ammonium methacrylate polymer (QAMP) at 5% by mass to Clearfil SE Bond as experimental group, Clearfil SE Bond as negative control group, and Clearfil Protect Bond as positive control group. The results showed that experimental group demonstrated the minimum inhibitory /bactericidal concentration (MIC/MBC) values and an inhibition zone against Lactobacillus casei (L. casei) and Actinomyces naeslundii (A. naeslundii) similar to the positive control, and higher MIC/MBC values and smaller inhibition zone than the negative control for S. mutans, L. casei, and A. naeslundii, and that no statistically significant difference in the resin-dentin bond strength (μTBS) was observed between experimental and negative control groups immediately, after 6 months, or 12 months of water storage.…”

“…The antibacterial effect against two E. faecalis strains (ATCC and an endodontic isolate) were assessed, and results had shown that addition of QPEI nanoparticles improved the killing ability of PCS against biofilms of both E. faecalis strains and the effects of AH Plus on the biomass of biofilms from the ATCC strain. Moreover, there were no relevant changes in physicochemical and 95) quaternary ammonium polyethyleneimine QPEI unpolymerizable composite resin 24) , endodontic materials [89][90][91] quaternary ammonium dimethacrylate QADM/IMQ polymerizable composite resin [25][26][27]32) , adhesive system 42) 2-methacryloxylethyl dodecyl methyl ammonium bromide MAE-DB polymerizable composite resin 28,29) 2-methacryloxylethyl hexadecyl methyl ammonium bromide MAE-HB polymerizable composite resin 28,29) 2-Dimethyl-2-dodecyl-1-methacryloxyethyl ammonium iodine DDMAI polymerizable composite resin 30) quaternary ammonium methacrylate QAM polymerizable composite resin 31) , adhesive system 5,53,54) 2-methacryloyloxyethyl phosphorylcholine MPC polymerizable composite resin 33) dimethylaminododecyl methacrylate DMADDM polymerizable adhesive system [43][44][45] quaternary ammonium methacrylate polymer QAMP unpolymerizable adhesive system [46][47][48] methacryloxylethyl cetyl ammonium chloride DMAE-CB polymerizable adhesive system [49][50][51][52] benzalkonium chloride BAC unpolymerizable adhesive system [55][56][57] , glass ionomer cement 73,74) , endodontic materials 87) poly-2-methacry...…”

Recent Advances in Adhesive Bonding: The Role of Biomolecules, Nanocompounds, and Bonding Strategies in Enhancing Resin Bonding to Dental Substrates

“…It was suggested that these agents may reduce dentin biodegradability of host-derived MMPs, thus improving the quality of the hybrid layer. According to this review, these agents may be applied after acid-etching (27), during the priming step as modified primers (69, 70), or during the bonding step as modified resin adhesives (71, 72). …”