Effects of diode and Nd:YAG laser irradiation on titanium discs: A scanning electron microscope examination

Background: Dental lasers have been recommended for uncovering submerged implants as well as decontaminating implant surfaces when treating peri-implantitis. The aim of this study was to show the possible alterations in titanium disc surfaces using an Nd:YAG or a diode laser. Methods: Three different titanium discs were used (sandblasted, titanium plasma-sprayed [TPS], and hydroxyapatite [HA] coated) to determine the effects of laser irradiation on these surfaces using a scanning electron microscope (SEM). The discs were either irradiated with a pulsed Nd:YAG laser with a contact handpiece and power settings of 2.0, 4.0, and 6.0W or with a diode laser at 5.0, 10.0, and 15.0W power settings and continuous wave (cw) in the contact handpiece. Irradiated areas were compared with control titanium sites which were not lased. The specimens were prepared for SEM examination after the disc irradiation. Results: The SEM examination demonstrated extensive melting in all of the Nd:YAG laser irradiated areas. Damage was seen in all TPS- and HA-coated discs even at the lowest power setting. Loss of porosity, coating microfractures, and a relatively smooth surface were observed. In contrast, the diode laser did not cause any damage or modify the disc surface. Regardless of the power setting, there was no visible difference between lased and non-lased surfaces after cw irradiation with the diode laser. Conclusions: From these findings, it was concluded that the diode laser (980 nm) does not damage titanium surfaces, which should be of value when uncovering submerged implants and treating peri-implantitis.