dents are caused by there not being enough molten plastic in the sprue area or the sprue cools off before the bait gets fully formed. when you pour the cavity full and top off the sprue the bait is still hot and will draw hot plastic down because as it cools it wants to expand and if the sprue cools off too fast it has nothing to draw from. as for air pockets those are all usually operator error always pour straight down the middle, when you move from side to side or off center you stand the chance of trapping a bubble. i pour sticks when i used to pour before i discovered the huge production gains with injection above 325 and went as fast as our 16 molds would let us.