In situ evaluation of microbial profile formed on Ti-6Al-4V additive manufacturing disks: 16S rRNA sequencing

Dental implants obtained by additive manufacturing may present changes in the microbiome formed. However, studies profiling the microbial communities formed on Ti-6Al-4V are lacking.

The purpose of this in situ study was to characterize the profile of the microbial communities formed on Ti-6Al-4V disks produced by additive manufacturing and machining.

Titanium disks produced by additive manufacturing (AMD) and machining (UD) were housed in the buccal region of removable intraoral devices. These devices containing both disks were used by eight participants for 96 hours. After every 24 hours of intraoral exposure, the biofilm that had formed on the disks was collected. The 16S rRNA genes from each specimen were amplified and sequenced with the Miseq Illumina instrument and analyzed. Total microbial quantification was evaluated by analysis of variance-type statistics using the nparLD package. The Wilcoxon test was used to evaluate alpha diversity (α=.05).

A difference was found in the microbial communities formed on additively manufactured and machined disks, with a reduction in operational taxonomic units (OTUs) for the AMD group compared with the UD group. Firmicutes and Proteobacteria were the most abundant phyla. Of the 1256 genera sequenced, Streptococcus predominated on both disks.

The microbiome of the biofilm formed on the Ti-6Al-4V disks was significantly influenced by the fabrication method. The AMD disks showed lower total microbial counts than the UD disks.