text: Effectiveness was compared statistically ( ANOVA/Tukey 's ) based on % area covered by deposited precipitate layer ( % DPL ) , % dye penetration inhibition ( % DPI ) and percentage of fully-open ( % FOT ) , partially-occluded ( % POT ) and completely-occluded ( % COT ) tubules in each block calculated relative to the number of tubules in their control blocks .