A preliminary in vivo trial of load transfer in mandibular implant-retained overdentures anchored in 2 different ways: allowing and counteracting free rotation.

This in vivo pilot methodologic study used 3 patients to investigate load transfer in mandibular implant-retained overdentures anchored in 2 different ways: allowing (gap condition) and counteracting (contact condition) free rotation. Load cells and strain-gauged abutments were used to evaluate occlusal load, load transmitted to the nonworking-side mucosa, and stress on the working-side abutment, in both contact and gap conditions. The occlusal load was reduced and load was shifted from abutments to mucosa in the gap versus the contact condition. In the contact condition, patients reported more comfort and felt that they could exert greater occlusal force.