An investigation of cuspal deformation and delayed recovery after occlusal loading

Abstract

OBJECTIVE: The purpose of this study was to investigate the extent of progressive cuspal displacement during prolonged occlusal loading (either continuous or cyclic) and delayed cuspal recovery following removal of the load. METHODS: Extracted maxillary premolars with extensive MOD cavity plus endodontic access were subjected to an occlusal load applied to both cusps, followed by a recovery period. Two types of loading were applied: (a) continuous load of 100, 200 and 300 N for 0.1--1000 s; (b) cyclic loading of 300 N at 0.83 Hz for 1--1000 cycles. Cuspal displacement during loading and subsequent recovery were measured with an extensometer attached to both cusps. RESULTS: Continuous loading..