Comparative analysis of manual and 3D scanning methods for backface deformation on anatomically complex surfaces

Oral biofilms that develop on dental implants contribute to peri-implant mucositis and peri-implantitis. These microbial communities are influenced by the physical and chemical properties of their environment, particularly oxygen availability. However, it is not entirely clear whether fluctuations in oxygen levels within the peri-implant pocket can affect the structure and composition of a well-established microbial colony.

To investigate this, a research team cultivated a biofilm consisting of four species - Streptococcus oralis, Actinomyces naeslundii, Veillonella dispar, and Porphyromonas gingivalis - under different oxygen conditions: normoxic (21% O2), hypoxic (1% O2), and anoxic (0% O2) for 21 days. They analyzed the biofilm's three-dimensional architecture, volume, and membrane integrity using LIVE/DEAD staining and confocal laser scanning microscopy.

They also assessed the community composition through quantitative real-time PCR and complemented it with Fluorescence In Situ Hybridization (FISH) to provide structural context.

Despite normoxia initially boosting early biofilm volume and membrane integrity, the community showed remarkable resilience over the long term, consistently maintaining a V. dispar-dominated structure across all oxygen gradients. Importantly, the obligate anaerobic pathogen P. gingivalis persisted as a minor presence (~1%) even under normoxic conditions, protected within the deeper layers of the biofilm.

These findings suggest that the oxygen levels found in clinical environments are not sufficient to significantly alter established oral biofilm communities. Furthermore, oxygen-sensitive pathogens can persist in a subclinical sanctuary, shielded by the non-pathogenic species that make up the majority of the biofilm.