Stressbreakers and the removable partial denture.

A laboratory study was designed to determine the effect of ""deactivation'' of stressbreakers on abutment tooth movement and ridge displacement. The Ticonium hidden-lock and the pin-Dalbo precision stressbreakers were tested. Results showed that ridge displacement was significantly decreased when the Dalbo was made rigid, and tooth movement was significantly decreased (during bilateral loading) when the hidden lock was made rigid.