Experimental composites containing quaternary ammonium methacrylates reduce demineralization at enamel-restoration margins after cariogenic challenge

André Coimbra Maia; Adrielle Mangabeira; Renato Vieira; Aline de Almeida Neves; Ricardo Tadeu Lopes; Thais Maria Pires; Gil Mendes Viana; Lúcio Mendes Cabral; Larissa Maria Cavalcante; Maristela Barbosa Portela

doi:10.1016/j.dental.2019.05.021

Experimental composites containing quaternary ammonium methacrylates reduce demineralization at enamel-restoration margins after cariogenic challenge

Dent Mater. 2019 Aug;35(8):e175-e183. doi: 10.1016/j.dental.2019.05.021. Epub 2019 Jun 13.

Affiliations

¹ Faculdade de Odontologia, Universidade Federal Fluminense, Niterói, RJ, Brazil.
² Faculdade de Odontologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
³ Laboratório de Instrumentação Nuclear, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
⁴ Faculdade de Farmácia, Laboratório TIF, Universidade Federal do Rio de Janeiro - UFRJ, Rio de Janeiro, RJ, Brazil.
⁵ Faculdade de Odontologia, Universidade Federal Fluminense, Niterói, RJ, Brazil; Núcleo de Pesquisa em Biomateriais Dentários, Faculdade de Odontologia, Universidade Veiga de Almeida - UVA, Rio de Janeiro, RJ, Brazil.
⁶ Faculdade de Odontologia, Universidade Federal Fluminense, Niterói, RJ, Brazil. Electronic address: mbportela@hotmail.com.

PMID: 31204047
DOI: 10.1016/j.dental.2019.05.021

Abstract

Objective: This study evaluated the influence of experimental composites containing quaternary ammonium monomers (QAM) at different concentrations and alkyl chains on demineralization at enamel-composite margins after cariogenic challenge.

Methods: Standardized 4×4mm cavities were cut into 35 bovine enamel blocks, which were randomly divided into seven groups (n=5) and restored with the following experimental composites and commercial materials: (G12.5) - 5% dimethylaminododecyl methacrylate (DMADDM) with a 12-carbon alkyl chain (G12.10) - 10% DMADDM, (G16.5) - 5% dimethylaminohexadecyl methacrylate (DMAHDM) with a 16-carbon alkyl chain (G16.10) - 10% DMAHDM, (CG) - control group (without QAM), (GZ250) - commercial composite (Filtek Z250^®), and (GIC) - glass ionomer cement (Maxxion R^®). After restorative procedures, initial microhardness was measured and experimental composites were subjected to Streptococcus mutans biofilm formation for 48h. After cariogenic challenge, the samples were washed and microhardness was reassessed. A 3D non-contact profilometer was used to determine surface roughness and enamel demineralization was assessed by micro-CT. Microhardness results were analyzed by the Kruskal-Wallis and Mann-Whitney tests and micro-CT results were analyzed by Tukey's HSD test (95% confidence interval).

Results: None of the materials could prevent mineral loss at the enamel-restoration margins. The addition of 10% DMAHDM yielded the lowest, albeit statistically significant, mineral loss (p<0.05). 3D non-contact profilometry showed enamel surface roughness modification after biofilm exposure. The CG had the highest roughness values. Micro-CT analysis revealed mineral loss, except for GIC.

Significance: The addition of 10% QAM with a 16-carbon chain in experimental composites reduced mineral loss at the enamel-restoration margins after cariogenic challenge.

Keywords: Biofilm; Demineralized enamel; Dental composite; Quaternary ammonium; Restorative dentistry; Streptococcus mutans.

MeSH terms

Animals
Biofilms
Cattle
Composite Resins
Dental Caries*
Dental Enamel
Glass Ionomer Cements
Methacrylates
Streptococcus mutans
Tooth Demineralization*

Substances

Composite Resins
Glass Ionomer Cements
Methacrylates