Frank P Nothdurft1, Konrad Neumann, Andreas W Knauber. 1. Department of Prosthetic Dentistry and Dental Materials Sciences, Dental School and Clinics, Saarland University, Homburg, Saar, Germany, frank.nothdurft@uks.eu.
Abstract
OBJECTIVES: The purpose of this in vitro study was to evaluate the influence of the superstructure-geometry on the fracture behavior of zirconia abutments (Compartis, DeguDent GmbH, Hanau, G). MATERIALS AND METHODS: Four different groups (n = 8) representing anterior single crown replacement were prepared. In groups 1 and 2, the implants were restored with customized all-ceramic abutments and anatomically shaped crowns (chromium cobalt alloy). Groups 3 and 4 received crowns with a geometry according to the international standard ISO 14801 (dynamic fatigue test for endosseous dental implants) with a spherical contact area. Groups 2 and 4 were subjected to mechanical aging in a chewing simulator (50 N × 1,200,000 cycles). Static loading until fracture was performed using a universal testing device at an angle of 30° to the implant axis. Fracture patterns were analyzed using SEM. RESULTS: In group 2, only one specimen survived mechanical aging. In group 4, one specimen fractured during the chewing simulation. Groups 1 and 2 showed significantly lower load-bearing capacity than groups 3 and 4. Artificial aging did not influence the fracture resistance. The SEM analysis revealed fatigue-related fracture patterns in those specimens, which failed during artificial aging. CONCLUSIONS: Drawing conclusions from ISO testing concerning clinical performance appears to be critical as anatomic superstructure geometries induce different fracture behaviors. CLINICAL RELEVANCE: ISO testing of zirconia abutments should be accompanied by load-bearing capacity testing under simulated clinical conditions to predict clinical performance.
OBJECTIVES: The purpose of this in vitro study was to evaluate the influence of the superstructure-geometry on the fracture behavior of zirconia abutments (Compartis, DeguDent GmbH, Hanau, G). MATERIALS AND METHODS: Four different groups (n = 8) representing anterior single crown replacement were prepared. In groups 1 and 2, the implants were restored with customized all-ceramic abutments and anatomically shaped crowns (chromium cobalt alloy). Groups 3 and 4 received crowns with a geometry according to the international standard ISO 14801 (dynamic fatigue test for endosseous dental implants) with a spherical contact area. Groups 2 and 4 were subjected to mechanical aging in a chewing simulator (50 N × 1,200,000 cycles). Static loading until fracture was performed using a universal testing device at an angle of 30° to the implant axis. Fracture patterns were analyzed using SEM. RESULTS: In group 2, only one specimen survived mechanical aging. In group 4, one specimen fractured during the chewing simulation. Groups 1 and 2 showed significantly lower load-bearing capacity than groups 3 and 4. Artificial aging did not influence the fracture resistance. The SEM analysis revealed fatigue-related fracture patterns in those specimens, which failed during artificial aging. CONCLUSIONS: Drawing conclusions from ISO testing concerning clinical performance appears to be critical as anatomic superstructure geometries induce different fracture behaviors. CLINICAL RELEVANCE: ISO testing of zirconia abutments should be accompanied by load-bearing capacity testing under simulated clinical conditions to predict clinical performance.
Authors: Roland Glauser; Irena Sailer; Arnold Wohlwend; Stephan Studer; Monica Schibli; Peter Schärer Journal: Int J Prosthodont Date: 2004 May-Jun Impact factor: 1.681
Authors: Maria Beatriz Bello Taborda; Gabriela Sumie Yaguinuma Gonçalves; Cecília Alves de Sousa; Wirley Gonçalves Assunção Journal: Int J Dent Date: 2021-11-18