Effect of Er:YAG, CO2 and diode laser irradiation on surface properties of zirconia endosseous dental implants

Background and Objectives: Zirconia implants (ZI) are becoming more popular in implant dentistry, as a result of their favorable esthetic outcome. However, little is known about the impact laser application has on this material in the course of peri-implantitis treatment. The objective of this investigation was to analyze the influence of Er:YAG, CO2 and diode laser irradiation on polished ZI. Material and Methods: Yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramic disks were irradiated at different power settings with either an Er:YAG, CO2 or diode laser. The surface of the disks was analyzed by scanning electron microscopy (SEM) and confocal 3D white light microscopy (CWLM). In addition energy-dispersive X-ray (EDX) analysis was performed on all disks. Six specimens were used for each parameter set of each laser. Results: SEM analysis demonstrated that, regardless of the power settings, neither the diode laser nor the Er:YAG laser caused any visible surface alterations to ZI. The results of the CWLM were in agreement with the SEM pictures. However, Er:YAG irradiation did penetrate through the disks. At various power settings, the CO2 treatment was characterized by material cracking and melting. The increased roughness values (from CWLM) of the ZI underlined the SEM observations. Conclusion: In contrast to diode and Er:YAG laser irradiation, the CO2 laser revealed distinct surface alterations to zirconia at various laser parameters. However, the Er:YAG laser cannot be recommended for the treatment of ailing implants, as the laser beam penetrates the material. In this respect, currently, diode lasers seem to be the only laser systems offering surface preservation and safety in the treatment of peri-implantits with ZI.