A photoelastic study of stress distribution by a mandibular split major connector.

This investigation evaluated the stress patterns in a photoelastic model produced by three different mandibular major connectors. The results were as follows. There were minimal differences in stress generated by the rigid and the short split frameworks. When the split extended to the midline, the stress on the distal-extension abutment was in a more vertical direction and decreased in magnitude. The stress in the edentulous portion of the distal-extension side was increased with the long split when force was applied. When force was applied to the tooth-supported side of the removable partial denture, the difference in stress among the three frameworks was insignificant. The long split major connector is a viable, inexpensive alternative to manufactured stress breakers for distal-extension removable partial dentures.