Movement of artificial teeth during complete (or implant supported complete over-dentures) may compromise the occlusion of these dentures, and may lead subsequent traumatic occlusion, that may need correction of the occlusion which is unfavorable due to loss of intended balanced occlusion especially when anatomic artificial teeth are used. We aimed to evaluate the effect of three methods of flasking commonly used in dental laboratories, on the artificial teeth position, and, surface roughness in order to find why and when these changes take place during flasking, packing, and curing processes. In this study 45 identical lower complete dentures were constructed by the duplication method, stainless steel bars were placed in the first premolar and first molar on each side of the denture using a surveyor engine device. Five samples were cut off the dentures to measure the surface roughness and, radiographs were taken at three stages of the flasking process. In the first group plaster was used as a second pour; in the second group, a silicon layer was used to the level of the occlusal plane; in the third group, the upper half was filled completely with silicon dough. The angles of the first group significantly changed starting from the flasking stage; the second group showed the least changes, first and the third groups demonstrated the significant higher changes in teeth position. The surface roughness of the first group was significantly higher than in the other two groups. Using a layer of silicon for splitting the waxed denture from the gypsum product considerably decreased the surface roughness and the artificial teeth movement.