Middle Infrared Laser Effects on Titanium Implants

Methods: Machined titanium disks and Neoss Bimodal implants were irradiated at 90 degrees with focused and defocussed beams from MIR lasers (Er:YAG KaVo KEY3; and Er,Cr:YSGG Biolase Waterlase MD) with multiple individual exposure points. A matrix design was used with 4 energy densities, 4 peak powers, and 3 pulse durations. Samples were examined under a stereomicroscope for visual changes, and then under SEM for changes in surface topography.

Results: Shadowing and projection/defocussing effects occurred at the macro level on implant threads according to the position of the incoming beam. Greater surface effects occurred with increasing MIR laser pulse energy and increasing peak power (shorter pulses). Effects were more pronounced on the implant surface than on plain disks. Plasma formation occurred at peak powers of 500-1,000W, without surface changes. The ablation threshold at which melting first began was 32J/cm². Melting of surface microfeatures occurred at peak powers of 1700W (energy density 120J/cm²), and central cratering with peripheral melting at peak powers of 2100W (energy density 200J/cm²).

Conclusions: Implant surface ablation thresholds are well above parameters used currently in clinical practice for debriding teeth using MIR lasers (60 mJ per pulse, peak power 170 watts; energy density 12 J/cm²), indicating that implant surface damage is unlikely during clinical use for implant debridement at the same settings.

Implants for this study were provided by Neoss.