PURPOSE: Biofilms on oral piercings might serve as a bacterial reservoir in the host and lead to bacteraemia and even septic complications. The use of piercing materials less susceptible to biofilm accumulation could contribute to alleviation of problems. The present study aimed to assess biofilm formation on four commercially available, surface characterized piercing materials in vitro (polytetrafluoroethylene, titanium, stainless steel, and polypropylene).
MATERIAL AND METHODS: Autoclave-sterilized piercings were surface characterized by X-ray photoelectron spectroscopy, contact angle measurements, and atomic force microscopy. Biofilms were grown for 1, 4, or 20 h on the piercing surfaces by immersion in pooled human whole saliva. Colony forming units (CFUs) were determined. For fluorescence microscopy, samples were stained with DAPI.
RESULTS: All four piercing materials included showed significant amounts of biofilm after 20 h of incubation. Biofilm formation was significantly lowest on polytetrafluoroethylene piercings (p < 0.001), and was mainly determined by wettability – which was significantly lowest for polytetrafluoroethylene (p < 0.001) – and the prevalence of carbon- and oxygen-rich components. Surface roughness measurements showed no statistically significant differences, but standard deviations were rather high. High standard deviations are caused by substantial pits and elevations and are due to poor machining quality in the manufacture of the piercings.
CONCLUSION: Biofilm formation on oral piercings was mainly determined by surface free energy and the prevalence of carbon- and oxygen-rich components, and was significantly lowest on polytetrafluoroethylene piercings. The findings indicate that oral piercings might serve as a reservoir of potentially pathogenic bacterial species.