Effects of Porphyromonas gingivalis on Titanium Surface by Different Clinical Treatment

As peri-implantitis is associated with biofilm development, the characteristics of titanium implants may influence biofilm formation, and thereby increase the risk for inflammation. The objective of this study was to evaluate the effect of titanium surface roughness induced by various debridement methods of peri-implants, such as the use of an ultrasonic scaler, rubber polishing cup, gallium–aluminum–arsenide laser, and chlorhexidine (CHX) rinse, on Porphyromonas (P.) gingivalis. Surface debridement was performed by immersing titanium discs in CHX rinse for 24 h or treatment with a laser, polishing cup, or ultrasonic scaler for 60 s. Surface topography was examined using a profilometer. For the bacterial assay, specimens were inoculated with P. gingivalis for 2 h and incubated for 6, 12, and 24 h. After incubation, bacterial adhesion on the discs was quantified via spectrophotometric evaluation. Moreover, scanning electron microscopy (SEM) images were analyzed to quantify P. gingivalis colonization on the titanium surfaces. Data were analyzed using one-way analysis of variance and Pearson’s correlation test (p < 0.05). Scaled surfaces showed the highest surface roughness (R_a, p < 0.001). There was a significant positive correlation between R_a values and optical density measurements at all incubation times (p < 0.05). The quantitative evaluation of P. gingivalis attachment through SEM revealed that the amounts of bacteria were significantly lower in the control, laser, and CHX groups compared with those in the other groups (p < 0.05). Moreover, a significant positive correlation was found between R_a and attached P. gingivalis number obtained from SEM images (p < 0.05). In conclusion, polishing, CHX, and laser treatments of titanium surfaces provide the highest reduction in P. gingivalis biofilm mass and regrowth in vitro. This effect was enhanced as the smoothness of the titanium surface was increased.