Influence of dental implant surfaces on oral biofilms and host immune response

Peri-implantitis, driven by microbial‒host immune interactions, is the leading reason that dental implants fail. Implant surface design plays a crucial role in microbial colonization.

To investigate how surface characteristics of implant materials impact periodontal disease biofilm formation and host immune response.

Biofilms, cultured on Ti-6Al-4V and CoCr disks, had biomass quantified by crystal violet and microbial populations by agar enumeration. We assessed the influence of Ti-6Al-4V post-processing treatments on surface chemistry (energy dispersive spectroscopy), topography (optical profilometry) and microbial dynamics (through complex oral biofilm culture and 16S rRNA sequencing). To evaluate immune responses, biofilms were co-cultured with dysplastic oral keratinocytes, and IL-6, IL-8, IL-1β, TNFα and GRO-α ELISAs were performed.

Sandblasting markedly increased surface roughness (3.9 vs 0.2-0.6 R_a), biomass (0.72-0.99 vs 0.13-0.62 AU) and total viable counts (TVC). Ti-6Al-4V demonstrated significant enrichment of firmicutes compared to CoCr, together with increased proportions of sulphate-reducing and periodontal disease-associated taxa. Rougher surfaces provoked stronger immune activation under microbial challenge, highlighting the link between topography and host response.

Surface roughness influenced biofilm formation and inflammation. Assessment of implant materials should integrate microbial and cellular responses for deeper insights. Smoother surfaces, combined with antimicrobial coatings may help reduce peri-implant disease.