Periowave eradicates biofilms from dental implants without altering surface chemistry

Objectives:  To determine the effect of Periowave™ exposure on dental implant surface chemistry, and to evaluate the efficacy of this photodynamic disinfection (PDD) system in eradicating P. gingivalis biofilms from the surface of several common dental implants.

Methods:  Implants from three manufacturers were exposed to activated and non-activated Periowave™ (sterile water control) and examined using Electron Spectroscopy for Surface Analysis and high resolution carbon scan to determine whether the treatment had any effect on implant surface chemistry. Next, homogenous biofilms of P. gingivalis were grown anaerobically for 72hrs on dental implant screws (n=12) suspended vertically into 12-well culture plates. After a 30sec rinse to remove free-floating organisms, treatment implants were placed in Periowave™ for 30sec, followed by circumferential illumination for 60sec using Periowave™ laser handpieces and light guide tips (220mW, 670nm) placed at 120 degree angles around the implant screw. This procedure was repeated for a total of two 60sec PDD exposures per implant. Surviving biofilm organisms were recovered from implant surfaces and plated onto Brucella Blood Agar supplemented with hemin and vitamin K. Colonies were counted after 7 days anaerobic growth. Controls consisted of no treatment, light-only, and photosensitizer-only conditions.

Results:  Exposure to Periowave™ had no significant effect on the surface chemistry of the dental implants tested. Furthermore, treatment with the Periowave™ system significantly reduced P. gingivalis biofilm viability on these implants. Implant samples A and B, with titanium oxide surface chemistry, showed a >2log₁₀ (>99%) reduction from control. Treatment of hydroxyapatite-coated (Sample C) implants also resulted in a >2log₁₀ (>99%) reduction from control. 

Conclusions:  Treatment with Periowave™ did not cause significant changes in the complex surface chemistry of the three dental implants tested in this study. Furthermore, treatment with this PDD system significantly reduced the viability of P. gingivalis biofilms grown on both HA-coated and titanium oxide implants.