from your question i take note that your surgery for leukoplakia is done with a laser probably a CO2 laser as it is quite hard for a diode laser to perform. The quality of tissue healing following a laser excision is far superior than conventional type and the healing shows no scarring due to the laser limitation of the cells called myofibroblast that is responsible for scarring, so you dont have to worry about speech, however lasers are to be used only by adequately trained doctors