Limited clinical research identifies prosthodontic maintenance requirements of mandibular overdentures using the Locator attachment system. Sixty-five edentulous participants received complete maxillary dentures opposing mandibular two-implant overdentures with either Locator nylon (n = 21), Southern plastic (n = 24), or Straumann gold (n = 20) matrices. Prosthodontic maintenance was recorded prospectively for 3 years using defined categories. Over the 3-year period, a mean 3.52 ± 4.8, 2.08 ± 1.9, and 5.5 ± 4.2 maintenance events occurred for Locator, Southern, and Straumann participants, respectively. Prosthodontic success rates of 90% in the Locator nylon group, 88% in the Southern plastic group, and 75% in the Straumann gold group were achieved.