Yucel Yilmaz1, Asude Yilmaz. 1. Department of Pedodontics, Atatürk University, Faculty of Dentistry, Erzurum, Turkey. yyilmaz25@atauni.edu.tr
Abstract
PURPOSE: The objective of this study was to determine the in vitro shear bond strength of 2 different repair materials for anterior preveneered stainless steel crowns (SSCs) after bond failure in the prefabricated veneers. METHODS: Sixteen preveneered anterior SSCs were used. Each of the preveneered crowns was cemented with a luting glass ionomer cement onto cast die. Each die was placed into a mechanical testing machine. A force was applied on the veneer at the incisal edge, with a crosshead speed of 0.05 inches/minute until the initial original facial facing material fractured or dislodged. Fracture or dislodgment failure of the initial original facial facings was evaluated and photographed. Specimens were divided into 2 equal repairing procedure groups. Group 1 was repaired using Tetric Flow, a flowable resin composite. Group 2 was repaired using Major Resin, a crown and bridge veneering resin. After the repairing procedure, crowns were stored in water at room temperature for 24 hours and then thermocycled. The crowns repaired were debonded in the test machine in the same manner as the initial facial facing fracture test. The debonding failure of the repaired crowns also was evaluated and photographed. RESULTS: There was a statistically significant difference between the initial original veneer material and groups 1 and 2 (P < .000) and between groups 1 and 2 (P < .001). CONCLUSIONS: In this in vitro study, it was determined that shear forces of the repair materials were lesser than bond forces of the original veneer material to the stainless steel metal base.
PURPOSE: The objective of this study was to determine the in vitro shear bond strength of 2 different repair materials for anterior preveneered stainless steel crowns (SSCs) after bond failure in the prefabricated veneers. METHODS: Sixteen preveneered anterior SSCs were used. Each of the preveneered crowns was cemented with a luting glass ionomer cement onto cast die. Each die was placed into a mechanical testing machine. A force was applied on the veneer at the incisal edge, with a crosshead speed of 0.05 inches/minute until the initial original facial facing material fractured or dislodged. Fracture or dislodgment failure of the initial original facial facings was evaluated and photographed. Specimens were divided into 2 equal repairing procedure groups. Group 1 was repaired using Tetric Flow, a flowable resin composite. Group 2 was repaired using Major Resin, a crown and bridge veneering resin. After the repairing procedure, crowns were stored in water at room temperature for 24 hours and then thermocycled. The crowns repaired were debonded in the test machine in the same manner as the initial facial facing fracture test. The debonding failure of the repaired crowns also was evaluated and photographed. RESULTS: There was a statistically significant difference between the initial original veneer material and groups 1 and 2 (P < .000) and between groups 1 and 2 (P < .001). CONCLUSIONS: In this in vitro study, it was determined that shear forces of the repair materials were lesser than bond forces of the original veneer material to the stainless steel metal base.