Slides submitted to histochemical techniques will be evaluated with the aid of a microscope (CARL ZEISS, Germany). The first evaluation will determine if the epithelium has been completely removed. The second evaluation will be from the edge of the epithelial incision to the division that separates the lamina propria of the submucosa, measured in 5 different points. The total extent of the graft will be the sum of the last two measurements (Harris et al, 2003). All counts will be performed by a single calibrated examiner.