Failure Modes with Point Loading of Three Commercially Available Denture Teeth

Abstract

A common problem associated with implant-supported prostheses is the fracture of denture teeth. This study was designed to compare the fracture modes of three denture teeth by compressive load at a 30 degrees off-axis angle. Three denture teeth (Vident Duostat, Ivoclar Vivadent, and Dentsply Trubyte) processed to two denture base processing systems [injection-molded (IM) SR-Ivocap system and compression-molded (CM) denture base resin] were evaluated. Each specimen was processed to a metal framework. Ultimate failure strength of each system when point loaded at a 30 degrees off-axis angle was recorded, along with a visual inspection of each specimen. The average load fracture for each group was (in N): Vident CM 1106.97 +/- 223.20, Vident IM 1168.18 +/- 322.52, Dentsply CM 1098.08 +/- 286.32, Dentsply IM 1023.80 +/- 282.45, Ivoclar CM 1616.98 +/- 204.87, and Ivoclar IM 1373.54 +/- 282.58. There was a significant difference between the groups and the Ivoclar CM group. The Ivoclar CM group had the highest average load force, and the Dentsply IM group had the lowest average load force. On average, the teeth within the groups fractured at a higher compression force than the average maximum occlusal force in natural dentition. Dentsply and Vident denture teeth fractured more horizontally, and the Ivoclar denture teeth fractured more vertically within the groups. There was no significant difference among the groups between the IM and CM processing methods. In the present in vitro study, all specimens were able to withstand 30 degrees off-axis loading with the exception of one specimen. With these results, this would indicate that these denture teeth are able to withstand normal occlusal forces.