The effect of two different types of attachments retaining mandibular implant overdentures on measured strains using static loading conditions

Abstract

Controversy persists as to the design and indications for different attachment systems for overdentures. Overdenture attachment design magnitudes around implants. The purpose of this study was to compare the effects of two resilient stud attachment designs on strain magnitudes around implant retained mandibular overdentures. Two acrylic resin casts were fabricated for use in this study. Two implants 13 mm in length and 3.7 mm in diameter were screwed bilaterally into each cast in the area between the canine and lateral incisor. For the first cast, the Locator attachments were secured to the implants: Model 1. For the second cast, Ball and socket attachments were secured to the implants: Model 2. Electric strain gauges were used to record the microstrains generated in the two models.Four strain gauges were used bilaterally to measure the microstarins produced at the labial,lingual, mesial and distal surfaces of the implants, Furthermore, two strain gauges were installed on the buccal surface parallel to the long axis of the ridge to measure microstarins recorded on the ridge for each cast. A loading device was used to produce standardized static loads within the reported physiologic limits of 50 N on either side of the occlusion rims over the implants directly. The readings of the loaded and unloaded sides were recorded in microstrain units from the multi-channel strain indicator. Microstrains were recorded for both the loaded and unloaded side at each time of load application. With respect to the loaded and unloaded implants, the Locator attachment system showed statistically significant lower values than the Ball attachment system. Regarding the esidual ridge, the Ball attachment system showed statistically significant lower values.