Inlay‐retained cantilever fixed dental prostheses to substitute a single premolar: impact of zirconia framework design after dynamic loading

Abstract

The purpose of this in-vitro study was to evaluate the influence of the framework design on the durability of inlay-retained cantilever fixed dental prostheses (IR-FDPs), made from zirconia ceramic, after artificial ageing. Forty-eight caries-free human premolars were prepared as abutments for all-ceramic cantilevered IR-FDPs using six framework designs: occlusal-distal (OD) inlay, OD inlay with an oral retainer wing, OD inlay with two retainer wings, mesial-occlusal-distal (MOD) inlay, MOD inlay with an oral retainer ring, and veneer partial coping with a distal box (VB). Zirconia IR-FDPs were fabricated via computer-aided design/computer-aided manufacturing (CAD/CAM) technology. The bonding surfaces were air-abraded (50 μm alumina/0.1 MPa), and the frameworks were bonded with adhesive resin cement. Specimens were stored for 150 d in a 37°C water bath during which they were thermocycled between 5 and 55°C for 37,500 cycles; thereafter, they were exposed to 600,000 cycles of dynamic loading with a 5-kg load in a chewing simulator. All surviving specimens were loaded onto the pontic and tested until failure using a universal testing machine. The mean failure load of the groups ranged from 260.8 to 746.7 N. Statistical analysis showed that both MOD groups exhibited significantly higher failure loads compared with the other groups (i.e. the three OD groups and the VB group) and that there was no significant difference in the failure load among the OD groups and the VB group. In conclusion, zirconia IR-FDPs with a modified design exhibited promising failure modes.

Failure loads of all‐ceramic cantilever fixed dental prostheses on post‐restored abutment teeth: influence of the post presence and post position

“…However, clinical recommendation is limited because of the in vitro nature of the test design with isolated loading on the distal aspect of the cantilever extensions. The lever defined by the loading point with a distance of 3.5 mm to the adjacent abutment tooth simulated a centric contact point and was recommended to reduce adverse loading . The conclusions are strongly limited to our load application design which eliminates loading at a more distal point or any eccentric contact.…”

Minimal invasive prothetische Versorgung als wertvolle Alternative zum kieferorthopädischen Lückenschluss bei Zahnnichtanlagen

“…Vollkeramische Adhäsivbrücken zum Ersatz von Eck-und Seitenzähnen wendet der Autor seit mehr als 10 Jahren erfolgreich in solchen Einzelfällen an, in denen Implantate nicht oder nur mit unverhältnismäßig großem Aufwand möglich sind, oder wenn Patienten eine Implantation ablehnen. Da für diese Anwendung bisher nur vorläufige wissenschaftliche Daten existieren [31][32][33][34], werden die Patienten explizit darüber aufgeklärt, dass der Einsatz von einflügeligen vollkeramischen Adhäsivbrücken zum Ersatz von nicht angelegten Prämolaren und Eckzähnen noch als quasi experimentell anzusehen ist. Die hauptsächlichen Risiken bestehen im Retentionsverlust oder der Fraktur der einflügeligen Adhäsivbrücke.…”

Effect of frame design on the fracture strength of a zirconia crown and porcelain-faced crown

“…In much of the research to date, reports have indicated that the mechanical properties of zirconia are equal to or superior to those of metal. However, if we consider the device's function as a long-term prosthetic device under mastication, it is essential to measure its fracture strength, while taking into consideration its clinical form and the unfavorable intraoral environment [10][11][12][13] . Previous studies have analyzed occlusal contact damage-associated fracture behavior for zirconia crowns 14) and have demonstrated the utility of supportive designs and supportive regions in frame designs when loads are applied to the occlusal surface at various points 15) .…”