Fractographic features of glass-ceramic and zirconia-based dental restorations fractured during clinical function.
Bottom Line: Fourteen lithium disilicate glass-ceramic restorations and 13 zirconia-based restorations were retrieved and analyzed.One crown was not categorized because of difficulty in orientation of the fragments.Three cases of occlusal chipping were found.
Affiliation: Department of Clinical Dentistry, Faculty of Medicine and Dentistry, University of Bergen, Bergen, Norway.Show MeSH
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Mentions: Twenty-seven fractured all-ceramic single-tooth restorations were collected and analyzed. The restorations were submitted by dentists and dental technicians in Norway. We announced our plans in several lectures and seminars and encouraged participants to send the fractured restorations to us. The remaining fragments were carefully removed by the dentist, intact or by splitting with a burr if necessary, packed in soft packaging material to avoid damage, and sent to us by post. Any damage done during removal, such as that caused by drilling or handling with metal instruments, was distinguishable by optical microscopy. Only surfaces that were not destroyed by handling were used in the analyses to ensure that the original fractures were the object of interest. The dentists supplied the information available on time since cementation, type of cement used, and any special events that may have occurred. Unfortunately, information regarding materials used in core, veneer, and cement was incomplete. Information on how the crowns were produced was not included, so it is uncertain whether they were pressed, soft machined, or hard machined. The crowns were inspected visually to determine the shape and orientation of the crown, taking care not to destroy any surfaces (Fig.1). The crowns were cleansed with ethylenediaminetetraacetic acid (EDTA) and then placed in distilled water in an ultrasonic bath for 5 min to remove debris. Further cleansing was undertaken with acetone if necessary. Analyses were performed in an optical light microscope (Leica DM IRM; Leica, Wetzlar, Germany) with a gradual increase in magnification.
Affiliation: Department of Clinical Dentistry, Faculty of Medicine and Dentistry, University of Bergen, Bergen, Norway.