Human In Situ Study of the effect of Bis(2-Methacryloyloxyethyl) Dimethylammonium Bromide Immobilized in Dental Composite on Controlling Mature Cariogenic Biofilm

Abstract

Cariogenic oral biofilms cause recurrent dental caries around composite restorations, resulting in unprosperous oral health and expensive restorative treatment. Quaternary ammonium monomers that can be copolymerized with dental resin systems have been explored for the modulation of dental plaque biofilm growth over dental composite surfaces. Here, for the first time, we investigated the effect of bis(2-methacryloyloxyethyl) dimethylammonium bromide (QADM) on human overlying mature oral biofilms grown intra-orally in human participants for 7–14 days. Seventeen volunteers wore palatal devices containing composite specimens containing 10% by mass of QADM or a control composite without QADM. After 7 and 14 days, the adherent biofilms were collected to determine bacterial counts via colony-forming unit (CFU) counts. Biofilm viability, chronological changes, and percentage coverage were also determined through live/dead staining. QADM composites caused a significant inhibition of Streptococcus mutans biofilm formation for up to seven days. No difference in the CFU values were found for the 14-day period. Our findings suggest that: (1) QADM composites were successful in inhibiting 1–3-day biofilms in the oral environment in vivo; (2) QADM significantly reduced the portion of the S. mutans group; and (3) stronger antibiofilm activity is required for the control of mature long-term cariogenic biofilms. Contact-killing strategies using dental materials aimed at preventing or at least reducing high numbers of cariogenic bacteria seem to be a promising approach in patients at high risk of the recurrence of dental caries around composites.

Tooth sealing formulation with bacteria‐killing surface and on‐demand ion release/recharge inhibits early childhood caries key pathogens

“…The biointeractivity with the microenvironment surrounding the sealing materials is expected to prevent the attack from cariogenic pathogens and provide essential ions, such as calcium and phosphate, to restore the physiological equilibrium between tooth minerals and oral fluids. Our previous studies have demonstrated that dimethylaminohexadecyl methacrylate (DMAHDM), which can be covalently bonded and copolymerized with dental monomers, is very useful in decreasing the overall bacterial growth in resin‐based formulations (Cheng et al, 2012; Melo et al, 2018; Zhang et al, 2015; Zhou et al, 2019). Still, its performance on ECC‐linked key pathogens is not investigated yet.…”

In vivo Microbial Diversity Analysis on Different Surfaces of Dental Restorative Materials via 16S rDNA Sequencing

“…At present, many novel restorative materials have antimicrobial effects, including effects on caries-related and periodontitis-related microorganisms [ 34 – 37 ], mainly through the inhibition of the formation of bacterial biofilms and inhibition of the destruction of tooth structure by acid-producing metabolic pathways [ 38 , 39 ]. However, the application of clinical restorative materials is mostly dependent on the cost, aesthetics, the properties of the materials, and patients’ choice and economic conditions, rather than on the individual differences and the effects on micro-ecological diversity in the oral cavity [ 40 , 41 ].…”

Emerging Contact-Killing Antibacterial Strategies for Developing Anti-Biofilm Dental Polymeric Restorative Materials

“…In a recent study, the antibacterial properties of resin composites containing quaternary ammonium with 12 carbon chain lengh investigated using an in situ model [ 68 ]. Patients were asked to wear an intraoral device containing the resin composite specimens, and two weeks later the attached biofilms were collected.…”

“…Figure 8 demonstrates the quantification of total microorganisms, total Streptococci , Mutans streptococci , and Lactobacilli biofilms 7 and 14 days after wearing the devices. The CFUs of total microorganisms after seven days were reduced significantly in QADM resin composites compared to the control, but no significant inhibition was observed with total Streptococci , Mutans streptococci , and Lactobacilli [ 68 ]. After 14 days, even though QADM resin composites had fewer CFUs counts than control, the amount of reduction was not significant.…”