Dental laser has been increasingly used in implant surgery and the use of different lasers proposed. It has been suggested that laser may be beneficial in reducing surgical trauma and discomfort during the second phase of implant surgery and peri-implantitis treatment. Purpose The aim of the study was to investigate the effect of dental lasers (CO2, Er:YAG, Er,Cr:YSGG) on the surface of implant and temperature change during laser irradiation for determining optical dose of laser irradiation in vitro model. Materials and Methods CO2 (λ=10.6㎛, UM-L25, Unionmeical, Korea), Er:YAG (λ=2,940㎚, SDL-3300EN, B&B system, Korea), Er,Cr:YSGG (λ=2,780㎚, Waterlase, Biolase, USA) laser irradiated on the surface of implant with different energy and frequency. A scanning electron microscope study was presented for observation of surface change. And thermocouples prepared to estimate thermal increasement of implant body during laser irradiation of implant surface. Results All of three dental laser systems can induce implant surface alterations with high energy irradiation. Melting and glazing were observed on the implant surface. But for selective range of power output, there was no significant morphologic change on the implant surface in three dental laser systems. CO2 laser produced minimal temperature changes with forming carbonization layer on the implant surface. But in irradiation dose for clinical application, there was no temperature change on the implant body. Er:YAG and Er,Cr:YSGG laser did not excessively heat implant body, especially under a water spary. Conclusion When using the CO2, Er:YAG and Er,Cr:YSGG laser seems to be safe as far as possible surface alterations and thermal damage. But the power output must be limited so as to avoid implant and periimplant tissue damage. This experiment was carried out in vitro to standardize test conditions. The influence of surrounding tissue, saliva and blood on the laser effects require further scientific studies.