I am not sure what skin condition you wish to treat with the Fraxel but if you have dark skin you should probably avoid Fraxel and seek out the eMatrix. The eMatrix can be used on all color skin with little risk of hyper- pigmentation.
Fraxel Dual can be used safely on skin type five depending on the settings that are used for the treatment and the aftercare. It also depends on whether or not you want a single aggressive treatment or a series of lighter treatments. An experienced doctor who uses this laser can discuss the options with you in a face to face consultation.