The Trefoil system incorporates a pre-manufactured framework designed to the natural arch of the mandible and fixed on three implants. Adaptive joints compensate for the deviations from planned implant placement. A recent study1 investigated the mechanical performance of Trefoil and the range of passive fit provided by its adaptive joints.
Coupled finite element and mechanical analyses determined the maximum range of passive fit as ±0.4mm horizontal, ±0.5mm vertical and ±4.0° angular deviation. The median fatigue limit of Trefoil was measured for ideal (no implant deviation) and worst-case (maximum deviation within the passive fit range) scenarios. The Trefoil design showed high resistance to mechanical fatigue, 313 N in ideal and 304 N in worst cases.