Purpose:: to evaluate the influence of different  number and distribution used to retain mandibular overdentures using Peri-implant sulcus depth index, Peri-implant bleeding index and Peri-implant plaque index. Material and methods: Six completely edentulous patient received mandibular implant assisted overdenture. For each patient conventional complete denture was constructed.There are three groups of patient :Group I (single midline implant),GroupII(bilateral two implant at premolars area) were placed and Group III (one midline implant and two bilateral implant at premolars area). After three months of implant placement, the ball attachment was attached to implants. The peri-implant soft tissue changes included are: probing depth, modified bleeding index, modified plaque index (at the time of overdenture insertion and after six months from insertion). Results: The peri-implant clinical soft tissue changes showed statistical significant increase in probing depth and modified plaque index with the advancement of time, while bleeding index decreased significantly. Conclusion:: three-implant-supported overdentures seem to present a functional advantage vs two-implant-supported overdenture and one-implant-supported overdenture . Keywords: Mandibular Overdenture, ball attachment ,probing depth, bleeding index, plaque index.