Semiconductor (diode) laser - a great tool for working with soft tissues (gums and oral mucosa). It is known that they contain a large amount of hemoglobin and water: two well absorbed laser light chromophores. The absorption of radiation by water provides ablation (evaporation) of tissues, hemoglobin and oxyhemoglobin - good hemostasis (stops bleeding). For gingival and lip depigmentation the diode laser with the wavelength 810 nm is the best instrument to day.
The answer is straight and simple==== Diode lasers! It has the advantages of being portable, pocket-friendly, user-friendly and tissue-friendly. Diode lasers have de-mystified lasers.
The reason the diode is effective for pigmentation is it is a "pigment seeking" laser. This was emphasized early for a safety factor as a safety factor as if proper wavelength safety eye shields are not worn, the dark macula in the eyes will be damaged. The safety distance will vary with each laser device and the safety glasses will vary with each wavelength unless the glasses are coated with a wide wavelength spectrum. Perhaps that will help in remembering which laser is effective on hyper-pigmentation?
The least expensive products in this excellent category (in addition to their many other soft tissue applications) are PICASSO (AMD Lasers, USA) and ZOLAR (Zolar Lasers, Canada).
Diode laser (810 nm) have given the best results for me for both gum and lip depigmentation. For lip depigmentation i used non-contact mode with minimal watt setting and constant cooling of tissues.