enamel microabrasion

 The procedure was introduced by mckloskey. It is a technique to remove super- ficial enamel discoloration earlier 18% hydrochloric acid and laboratory pumice was used. By a combined chemical action of the acid and the abrasive effect of the pumice, a superficial enamel layer was removed improving the color of the enamel.  Later a compound called PREMA composed of HCL and silica carbide was used for removal of surface discoloration of enamel.