Inclusion Criteria:  completely edentulous individuals who had lacked teeth for more than 10 years, routine users of conventional complete prostheses. sufficient amount of remaining bone to receive the implants in the region of the mandibular canines (minimum height=15 mm/minimum ridge width= 5mm) no evidence of systemic or psychic pathology that might contraindicate the implant treatment.  Exclusion Criteria:  Those in which oral surgery or cognitive evaluations are contraindicated