Ionic liquid as antibacterial agent for an experimental orthodontic adhesive

Isadora Martini Garcia; Carolina Jung Ferreira; Virgínia Serra de Souza; Vicente Castelo Branco Leitune; Susana Maria Werner Samuel; Gabriela de Souza Balbinot; Amanda de Souza da Motta; Fernanda Visioli; Jackson Damiani Scholten; Fabrício Mezzomo Collares

doi:10.1016/j.dental.2019.05.010

Ionic liquid as antibacterial agent for an experimental orthodontic adhesive

Dent Mater. 2019 Aug;35(8):1155-1165. doi: 10.1016/j.dental.2019.05.010. Epub 2019 May 23.

Affiliations

¹ Dental Materials Laboratory, School of Dentistry, Federal University of Rio Grande do Sul, Ramiro Barcelos Street, 2492, Rio Branco, Porto Alegre, RS, 90035-003, Brazil. Electronic address: isadora.garcia@hotmail.com.
² Dental Materials Laboratory, School of Dentistry, Federal University of Rio Grande do Sul, Ramiro Barcelos Street, 2492, Rio Branco, Porto Alegre, RS, 90035-003, Brazil. Electronic address: carolinajungferreira@yahoo.com.br.
³ Laboratory of Molecular Catalysis, Institute of Chemistry, Federal University of Rio Grande do Sul, Bento Gonçalves Ave, 9500, Agronomia, Porto Alegre, RS, 91501970, Brazil. Electronic address: vivi_qui@hotmail.com.
⁴ Dental Materials Laboratory, School of Dentistry, Federal University of Rio Grande do Sul, Ramiro Barcelos Street, 2492, Rio Branco, Porto Alegre, RS, 90035-003, Brazil. Electronic address: vicente.leitune@ufrgs.br.
⁵ Dental Materials Laboratory, School of Dentistry, Federal University of Rio Grande do Sul, Ramiro Barcelos Street, 2492, Rio Branco, Porto Alegre, RS, 90035-003, Brazil. Electronic address: susana.samuel@ufrgs.br.
⁶ Dental Materials Laboratory, School of Dentistry, Federal University of Rio Grande do Sul, Ramiro Barcelos Street, 2492, Rio Branco, Porto Alegre, RS, 90035-003, Brazil. Electronic address: gabriela.balbinot@ufrgs.br.
⁷ Department of Microbiology, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Sarmento Leite Street, 500, Farroupilha, 90035-190, Brazil. Electronic address: amanda.motta@ufrgs.br.
⁸ Laboratory of Pathology, School of Dentistry, Federal University of Rio Grande do Sul, Ramiro Barcelos Street, 2492, Rio Branco, Porto Alegre, RS, 90035-003, Brazil. Electronic address: fernanda.visioli@ufrgs.br.
⁹ Laboratory of Molecular Catalysis, Institute of Chemistry, Federal University of Rio Grande do Sul, Bento Gonçalves Ave, 9500, Agronomia, Porto Alegre, RS, 91501970, Brazil. Electronic address: jackson.scholten@ufrgs.br.
¹⁰ Dental Materials Laboratory, School of Dentistry, Federal University of Rio Grande do Sul, Ramiro Barcelos Street, 2492, Rio Branco, Porto Alegre, RS, 90035-003, Brazil. Electronic address: fabricio.collares@ufrgs.br.

PMID: 31128938
DOI: 10.1016/j.dental.2019.05.010

Abstract

Objective: The aim of this study was to formulate and evaluate experimental orthodontic adhesives with different concentrations of 1-n-butyl-3-methylimidazoilium bis(trifluoromethanesulfonyl)imide (BMIM.NTf₂).

Methods: The experimental orthodontic adhesives were formulated with methacrylate monomers, photoinitiators and silica colloidal. The ionic liquid BMIM.NTf₂ was synthesized and characterized. BMIM.NTf₂ was added at 5 (G_5%), 10 (G_10%) and 15 (G_15%) wt.%. One group contained no BMIM.NTf₂ to function as control (G_Ctrl). The adhesives were evaluated for polymerization kinetics, degree of conversion (DC), Knoop hardness and softening in solvent, ultimate tensile strength (UTS), shear bond strength (SBS), thermogravimetric analysis (TGA), antibacterial activity and cytotoxicity.

Results: BMI.NTf₂ showed the characteristic chemical peaks. The polymerization kinetics were different among the groups. G_10% and G_15% showed higher DC (p < 0.05). G_5% and G_Ctrl had no differences for softening in solvent (p > 0.05). There were no differences for UTS (p > 0.05) and SBS (p > 0.05). TGA showed one different peak for G_15%. All groups with BMIM.NTf₂ showed antibacterial activity compared to G_Ctrl (p < 0.05) without cytotoxicity (p > 0.05).

Significance: To reduce biofilm formation around brackets and to prevent demineralization at susceptible sites, materials have been developed with antibacterial properties. In this study, a new experimental orthodontic adhesive was formulated with an imidazolium ionic liquid (BMIM.NTf₂) as antibacterial agent. The incorporation of 5 wt.% of ionic liquid decreased biofilm formation without affecting the physico-chemical properties and cytotoxicity of an experimental orthodontic resin.

Keywords: Antibacterial capability; Biocompatibility; Dental caries; Orthodontics; Tooth demineralization.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Anti-Bacterial Agents
Dental Bonding*
Dental Cements
Ionic Liquids*
Materials Testing
Orthodontic Brackets*
Resin Cements
Shear Strength

Substances

Anti-Bacterial Agents
Dental Cements
Ionic Liquids
Resin Cements