Biofilm formation on dental implants with different surface micro-topography: An in vitro study

Abstract

Objectives: To compare biofilm formation on whole dental titanium implants with different surface micro‐topography. Methods: A multispecies in vitro biofilm model consisting of initial (Streptococcus ora‐lis and Actinomyces naeslundii), early (Veillonella parvula), secondary (Fusobacterium nucleatum) and late colonizers (Porphyromonas gingivalis and Aggregatibacter actino‐mycetemcomitans) was grown for 96 hr on sterile titanium dental implants with either minimal (Sa: 0.5–1.0 mm) or moderate‐roughness titanium surfaces (Sa: 1.1–2.0 mm). The resulting biofilms were studied with Confocal Laser Scanning Microscopy (CLSM) and Scanning Electron Microscope. Concentrations (colony‐forming units per mL [CFU/ml]) of each bacterium were measured by quantitative Polymerase Chain Reaction (qPCR) and compared by Student t tests. Results: A biofilm, located mainly at the peak and lateral areas of the implant threads, was observed on both implant surfaces, with a greater biomass and a greater live/dead ratio in moderate‐ compared to minimal‐roughness surface implants. Statistically sig ‐nificant higher values of total bacteria (mean difference = 2.61 × 107 CFU/ml; 95% confidence interval — CI [1.91 × 106; 5.02 × 107]; p = 0.036), F. Nucleatum (mean difference = 4.43 × 106 CFU/ml; 95% CI [1.06 × 106; 7.80 × 106]; p = 0.013) and A. actinomycetemcomitans (mean difference = 2.55 × 107 CFU/ml; 95% CI [1.07 × 107; 4.04 × 107]; p = 0.002), were found in the moderate‐ compared to minimal‐roughness surface dental implants. Conclusions: Implants with moderate‐roughness surfaces accumulated more bacte ‐rial biomass and significant higher number of pathogenic bacteria (F. nucleatum and A. actinomycetemcomitans), when compared to implants with minimal‐roughness sur ‐faces, within a similar biofilm structure.