Five-year clinical trial using three attachment systems for implant overdentures

ObjectiveThe objective is to compare, in a prospective randomized clinical trial, three types of attachment systems for mandibular implant overdenture, focusing on costs, maintenance requirements and complications from baseline to the end of 5-year follow-up period. Materials and MethodsSixty-nine fully mandibular and fully/partially maxillary edentulous patients received two screw-type Straumann implants, in the mandibular canine region. New overdentures with three types of attachment systems were inserted according to an early-loading protocol: Group B (balls, divided into Subgroup B.1 - retentive anchor with gold matrix and Subgroup B.2 - retentive anchor with titanium matrix) (n=23), Group M (magnets) (n=23) and Group L (locator) (n=23). ResultsThe highest maintenance event number (195) was observed in Group B vs. 31 in Group L and 15 in Group M. Significantly more complications were recorded in Subgroup B.1 than in Subgroup B.2, Group M and Group L (P<0.05). Group M registered the highest prosthetic success (82.6%) in the 5years, followed by Group L (78.2%). Subgroup B.1 had the lowest success rate (50%). The magnet group recorded statistically significant higher costs, comparing with the other two groups (P<0.05). ConclusionsThe three attachment systems functioned well after 5years. The magnets had a low maintenance requirement and high success rate, despite the relatively increased initial costs. Retentive anchor with titanium matrix and locator may be a better choice from a financial point of view, taking into consideration the initial low cost of the components and also the reduced number of complications.