This study was designed to investigate the correlation between the biting force and masticatory muscle activity in patients treated by three treatment stages of single mandibular dentures: Conventional denture, Implant supported overdenture without attachment and Implant supported overdenture with attachment. Seven patients with single mandibular edentulous ridge (study group) and seven individuals with complete set of teeth (control group) were selected. The study period was divided into three stages the first treatment stage, each patient received a conventional lower complete denture. At the second stage, four root shaped implants placed into lower arch and denture was refitted to these abutments. At the third stage, the denture was connected to the implants through ball attachments. During each treatment stage, the maximum biting force was measured using the iload star sensor as well as the muscle activity during maximum clenching and chewing of soft and hard food through EMG. Besides the duration of mastication starting from the first chewing stroke to the swallowing was reported by the aid of a stop watch. Results: According to the results of this study, the biting force demonstrated a statistically significant increase by time for the three treatment stages. The highest biting force was recorded for the implant supported overdenture without attachment followed by the implant supported overdenture with attachment, while the lowest values were recorded for the conventional denture. On the other hand, the highest muscle activity was recorded for the conventional denture followed by the implant supported overdenture without attachment, while the lowest values were recorded for the implant supported overdenture with attachment. Conclusion: Masticatory efficiency, as expressed by an increase in the biting force accompanied by decreased muscle activity and shortened duration of mastication, gradually increased throughout the follow up period for the three treatment stages due to patient’s accommodation to the prosthesis.