Streptococcus Sanguis Biofilm Architecture and Its Influence on Titanium Corrosion in Enriched Artificial Saliva

Abstract

Bacteria biofilm formation on metals is well-known, while biofilm architecture varies under different conditions. To date, few studies have determined the possible contribution to corrosion of titanium made by biofilm architecture. We investigated the interaction between the oral Streptococcus sanguis biofilm architecture and its influence on titanium corrosion in enriched artificial saliva using electrochemical methods and microscopic study. Patchy biofilms were observed on titanium surface after being immersed in solution containing S. sanguis. The thickness and size of the patchy biofilms increased with an increase of immersion time. The extensive pits were clearly observed by scanning electron microscopy, showing that adsorption of S. sanguis on titanium promoted the localized corrosion. The electrochemical results indicated that the corrosion rates were clearly accelerated in the presence of S. sanguis. The low icorr and high Rt in the first 48 h indicated that a typical passive behavior still remained. Our study showed that the pitting corrosion of titanium was mainly attributed to the formation of a self-catalytic corrosion cell by the co-effect of patchy biofilm and organic acid secreted by S. sanguis.

Evaluation of oral microbial corrosion on the surface degradation of dental implant materials

“…The aim of this study was to compare the degradation effects of bacterial biofilm on the surface morphology and electrochemical behavior of four commercial dental implant surfaces: Ti‐SLA, Ti‐modSLA, TiZr‐SLA, and ZrO 2 ‐SLA. To simulate a worst‐case scenario for microbial‐induced corrosion and surface deterioration, implants were immersed continuously for 30 days in a polyculture consisting of three Streptococcus species implicated in peri‐implant diseases: S. mutans , S. sanguinis , and S. salivarius . Based on the literature, it was hypothesized that TiZr and ZrO 2 implants would exhibit a lower degree of bacterial colonization and surface degradation than pure Ti implants.…”

“…Streptococcus species, especially S. mutans , are opportunistic bacteria known to accelerate corrosion of Ti‐based dental implants . Bacterial adhesion is expected to induce corrosion of metallic substrates via metabolic byproducts including lactic acid and hydrogen peroxide which can lower the corrosion resistance of Ti .…”

“…Streptococcus species, especially S. mutans , are opportunistic bacteria known to accelerate corrosion of Ti‐based dental implants . Bacterial adhesion is expected to induce corrosion of metallic substrates via metabolic byproducts including lactic acid and hydrogen peroxide which can lower the corrosion resistance of Ti . Additionally, the accumulation of organic acids in these regions, creates localized, acidic environments which promote corrosion features including discoloration and pitting .…”

“…The ability of Streptococci to adversely lower the electrochemical behavior of Ti surfaces is well‐documented in the literature . However, the influence of bacterial adhesion on the corrosion behavior on TiZr remained unknown.…”

“…To simulate a worst-case scenario for microbial-induced corrosion and surface deterioration, implants were immersed continuously for 30 days in a polyculture consisting of three Streptococcus species implicated in peri-implant diseases: S. mutans, S. sanguinis, and S. salivarius. 39,40 Based on the literature, it was hypothesized that TiZr and ZrO 2 implants would exhibit a lower degree of bacterial colonization and surface degradation than pure Ti implants.…”