Inkjet-printed silver nanoparticle arrays for dental applications

This work discusses the effect of inkjet-printed silver nanoparticle (SNP) arrays on oral bacteria found in saliva in order to determine their potential as a possible path of infection prevention on oral implants and devices. A piezoelectric inkjet printer (FUJIFILM Dimatix) was used to print an aqueous solution of 0.6 wt% SNPs. Tests were performed by growing oral biofilms from saliva using tryptic soy broth (TSB) under static conditions using a 12-well plate. Oral biofilm was grown from saliva on both printed and blank pieces of titanium (Ti) alloy (TiAl6V4; Stryker) contained in 12-well plates. These were then analyzed using crystal violet (CV) and fluorescent live/dead stains followed by imaging by stereo and confocal microscopes, respectively. While there was no significant difference in the ratio of live to dead bacteria present on the Ti alloy pieces, the difference in thickness of biofilm was twofold. The CV stained biofilm images taken using the stereo microscope were analyzed using ImageJ software. A one-way ANOVA test showed a statistically significant difference (p <; 0.05) in biofilm coverage on the Ti alloy sample between the printed and blank areas. Within the unprinted areas there was an average of 97.8% biofilm coverage, while in the area of the micropattern there was only 87.5% biofilm coverage.