Evaluation of bacterial adhesion on machined titanium, Osseotite® and Nanotite® discs.

Purpose: Bacterial adhesion and colonization play a crucial function in the pathogenesis of peri-implant tissue infection, which is considered the main cause of fixture loss. The aim of this study is to evaluate the differences in bacterial adhesion between a machined titanium surface, a double acid etched surface (Osseotite®) and an Osseotite surface with Nanometer-scale Discrete Crystalline Deposition (DCD™) of calcium phosphate (CaP)(Nanotite®).Methods: Surface roughness properties of each sample were determined by a laser profilometer and scanning electron microscopy (SEM) observation. Bacterial adhesion on machined, Osseotite®, and Nanotite® discs were performed using the following bacterial strains: Streptococcus mutans CCUG 35176, Streptococcus sanguis CCUG 17826, Streptococcus salivarius CCUG 11878, Actinobacillus actinomycetecomitans CCUG 37002, Porphyromonas gingivalis CCUG 2521. The assessment of bacterial adhesion was performed by comparing two methods: Total Viable Count (TVC) estimation and Confocal Laser Scanning Microscopic (CSLM) studies.Results: The surface roughness parameter increased as follows: machined<Nanotite®<Osseotite®. The attachment of all bacterial strains performed by both methods showed a significant reduction on Osseotite® and even higher on Nanotite® in comparison to machined surfaces (p<0.05). The reduction in bacterial attachment was more significant on Osseotite® and Nanotite® for A. actinomycetecomitans, S. mutans and S. sanguis than for P. gingivalis and S. salivarius strains.Conclusions: Nanotite® samples showed the lowest amount of bacterial contamination in comparison to the smoother machined and rougher Osseotite® surfaces.