Oral bacterial adhesion forces to biomaterial surfaces constituting the bracket–adhesive–enamel junction in orthodontic treatment

Abstract

Bacterial adhesion to biomaterial surfaces constituting the bracket-adhesive-enamel junction represents a growing problem in orthodontics, because bacteria can adversely affect treatment by causing demineralization of the enamel surface around the brackets. It is important to know the forces with which bacteria adhere to the surfaces of these junction materials, as the strength of these forces will determine how easy it will be to remove the bacteria. We compared the adhesion forces of five initially colonizing and four cariogenic strains of bacteria to an orthodontic adhesive, stainless steel, and enamel, with and without a salivary conditioning film. Adhesion forces were determined using atomic force microscopy and a bacterial probe. In the absence of a salivary conditioning film, the strongest bacterial adhesion forces occurred to the adhesive surface (-2.9 to -6.9 nN), while adhesion forces to the enamel surfaces were lowest (-0.8 to -2.7 nN). In the presence of a salivary conditioning film, adhesion forces were reduced strongly, to less than 1 nN, and the differences between the various materials were reduced. Generally, however, initial colonizers of dental hard surfaces presented stronger adhesion forces to the different materials (-4.7 and -0.6 nN in the absence and presence of a salivary conditioning film, respectively) than cariogenic strains (-1.8 and -0.5 nN).

Influence of a polymerizable eugenol derivative on the antibacterial activity and wettability of a resin composite for intracanal post cementation and core build-up restoration

“…However, this relationship is not a linear correlation since the chemical composition of the surface tends to govern the interaction which depends on both the chemistry of the solid and immersion liquid and additionally the type of bacteria and growing media. This has resulted in conflicting reports with reports suggesting that materials with low SFE result in less bacterial adherence [23,40]; whilst other contrary reports found that bacterial adhesion decreased with increasing surface energy of substrates [41][42][43]. The addition of EgMA monomer containing a substituted aromatic ring into the formulation significantly increased the hydrophobicity leading to an increase of the surface contact angle and reducing the SFE values from 54.3 mN/ m for the control, to 47.7 and 44.8 mN/ m for composites containing 5% and 10% EgMA respectively.…”

Synergy of brushing mode and antibacterial use on in vivo biofilm formation

“…Atomic force microscopy has pointed out that bacterial adhesion forces to different materials used in orthodontics, including stainless steel, differ from the ones exerted by enamel surfaces in a strain-specific fashion. 35 Accordingly this explains 36 why biofilms on different materials have a different bacterial composition, including the enamel and stainless steel surfaces as involved here. Furthermore, the biofilm taken from retention wires will be more mature than biofilm taken from smooth enamel surfaces, as more biofilm will be left-behind after brushing on retention wires than on smooth enamel surfaces on which biofilm has to develop newly after each brushing.…”

Adhesion Forces and Composition of Planktonic and Adhering Oral Microbiomes

“…It is amazing how such small differences in bacterial adhesion forces can select strains from saliva to become members of the adhering microbiome. Earlier, it had already been found that initial colonizers of dental hard surfaces possess adhesion forces to saliva-coated enamel that are only 0.1 nN stronger than those of later-colonizing, more cariogenic strains (Mei et al, 2009). With respect to Staphylococcus aureus strains, a difference in adhesion force of 0.28 nN appears to dictate whether or not a strain can invade mammalian cells (Yongsunthon et al, 2007).…”