It has been hypothesized that zirconia might have a reduced bacterial adhesion compared to titanium; however, results from experimental studies are rather controversial. The aim of the present study was to compare biofilm formation on zirconia and titanium implant surfaces using an in vitro 3-species biofilm and human plaque samples.
Experimental disks made of titanium (Ti-M, Ti-SLA) or zirconia (ZrO2-M, ZrO2-ZLA) with a machined or a sandblasted and acid-etched surface topography were produced. Applying an in vitro 3-species biofilm or human plaque samples for bacterial adhesion to each type of disk after 72 hours of incubation was assessed using an anaerobic flow chamber model.
Zirconia showed statistically significant reduction in 3-species biofilm thickness compared to titanium (ZrO2-M: 8.41µm; ZrO2-ZLA: 17.47µm; Ti-M: 13.12µm; Ti-SLA: 21.97µm); however, no differences were found regarding 3-species-biofilm mass and metabolism. Human plaque analysis showed optical density values of 0.06 and 0.08 for ZrO2-M and ZrO2-ZLA, and values of 0.1 and 0.13 for Ti-M and Ti-SLA, respectively; indicating statistically significant reduction in human biofilm mass on zirconia compared to titanium. Additionally, zirconia revealed statistically significant reduction in human plaque thickness (ZrO2-M: 9.04µm; ZrO2-ZLA: 13.83µm; Ti-M: 13.42µm; Ti-SLA: 21.3µm) but a similar human plaque metabolism compared to titanium.
Zirconia implant surfaces showed statistically significant reduction in human plaque biofilm formation after 72 hours of incubation in an experimental anaerobic flow chamber model compared to titanium implant surfaces.