Streptococcus sanguinis adhesion on titanium rough surfaces: effect of shot-blasting particles

Abstract

Dental implant failure is commonly associated to dental plaque formation. This problem starts with bacterial colonization on implant surface upon implantation. Early colonizers (such as Streptococcus sanguinis) play a key role on that process, because they attach directly to the surface and facilitate adhesion of later colonizers. Surface treatments have been focused to improve osseointegration, where shot-blasting is one of the most used. However the effects on bacterial adhesion on that sort of surfaces have not been elucidated at all. A methodological procedure to test bacterial adherence to titanium shot-blasted surfaces (alumina and silicon carbide) by quantifying bacterial detached cells per area unit, was performed. In parallel, the surface properties of samples (i.e., roughness and surface energy), were analyzed in order to assess the relationship between surface treatment and bacterial adhesion. Rather than roughness, surface energy correlated to physicochemical properties of shot-blasted particles appears as critical factors for S. sanguinis adherence to titanium surfaces.

Probing the nanoadhesion of Streptococcus sanguinis to titanium implant surfaces by atomic force microscopy

“…8 Biofilm formation comprises of a series of stages, starting with the initial adhesion of early colonizing species 9 and continued by the attachment of secondary and increasingly pathogenic bacteria that can lead to disease. 10 In this context, Streptococcus sanguinis has been consistently reported as an initial colonizer in the process of oral 11 with the ability of adhering directly to the surface of biomaterials, giving place to the attachment of secondary bacterial strains. Attachment of S. sanguinis to substrates is mostly mediated by adhesins present on the bacterial cell wall surface, 12 with some studies even describing the existence of bacterial appendages such as pili as contributing factors in adhesion.…”

S. sanguinis adhesion on rough titanium surfaces: Effect of culture media

“…Shot blasting treatment was carried out at 0.25 MPa using a laboratory blasting machine (Model RB4 from Raytech Industries®). These treatment conditions (particle size, hardness and composition), were selected from a previous work [11] due to these particles ability to obtain roughness in the range of 1-10 μm, which maximizes bone-implant surface interlocking [12] and their excellent results in biocompatibility [13,14]. Prior to use, titanium disks were washed with distilled water, ethanol and acetone (15 min each), dried at room temperature and autoclaved.…”

“…To determine titanium surface energy a modified contact angle method, proposed previously [11], was used. Here, the advancing contact angle from three different liquids: water (Milli-Q), formamide (Sigma Aldrich®) and diiodomethane (Sigma Aldrich®) was measured using a Contact Angle System OCA from Dataphysics Instruments with CCD coupled and software (SCA20®).…”

“…2, A and B). This division has been explained in terms of the physico-chemical properties of particles, where the silicon carbide electron transfer properties, guide enhanced bacterial attachment behavior due to their free valence shell, which provide a reactive surface resulting in more favorable adhesion mechanism by sharing electrons [11]. By contrast, the inert nature of alumina limits that bacterial adhesion mechanism.…”

“…The second group of in vitro studies consists of adhesion bacterial experiments using routinary bacteria culture media. Studies on rough titanium samples [10,11] have permitted the analysis of initial bacterial attachment on surfaces with different kinds of surface modification treatments, in the best conditions of culture. These studies have established a direct correlation between surface characteristics (physico-chemical properties, roughness, surface energy,) and bacterial adhesion.…”