There are two basic emission modes for dental lasers - continuous-wave and free-running pulsed. Continuous-wave means that energy is emitted constantly for as long as the laser is activated. Carbon dioxide and diode lasers operate in this manner. A gated pulsed laser is a variation of continuous-wave and is accomplished with an electronically controlled mechanical shutter. This “gating” helps to minimize some of the undesirable residual thermal damage associated with continuous-wave devices. Free-running pulse mode is produced by a flash lamp, where true pulses - on the order of a few ten-thousandths of a second - emanate from the instrument. Nd:YAG, Er:YAG, as well as Er,Cr:YSGG devices operate as free-running pulsed lasers.

Flexible, small-diameter glass fibers are used to deliver diode and Nd:YAG laser energy. These bare fibers are usually used in contact with the tissue. Erbium and carbon dioxide devices use a more rigid glass fiber, semiflexible hollow wave-guides, or rigid sectional articulated arms to deliver the laser energy to the surgical site. Some of these systems employ additional small quartz or sapphire tips, which attach to the operating handpiece, and other systems are used without contacting the tissue. In addition, the erbium family of dental lasers uses a water spray for hard-tissue procedures; the water is typically switched off for soft-tissue surgery.