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SimuCrown - Simulation of functional aging – towards failure prediction of dental restorations
Projektleitung
	Dr. rer. nat. Andreas Kupsch BAM - 8.5 Röntgenbildgebung E-Mail: Andreas.Kupsch@bam.de
Beteiligte BAM-Fachbereiche
	BAM - 8.5, Röntgenbildgebung
Förderstruktur
	DFG - DFG - Sachbeihilfen
Projektbeginn
	01.03.2023
Projektende
	28.02.2026
Projektart
	Realisierte Antragsforschung
Themen-/Aktivitätsfeld
	THEMENFELD Analytical Sciences, * Zerstörungsfreie Prüfung und Spektroskopie
Abstract
	Full-coverage dental crowns are indirect restorations produced in the dental lab and they are permanently cemented to teeth or to implants. Crowns are clinically recommended for restoring teeth with significant tissue loss. They are the most common indirect dental restoration in Germany with more than 5 million crowns delivered every year. The fifth German Oral Health Study reported that 58% of younger seniors (65 to 74 years) and 42% of younger adults (35 to 44 years) had at least one full-coverage dental crown. Dental crowns are fabricated from different biomaterials that are usually harder and stiffer than the replaced natural tooth tissues, enamel and dentine. Computer aided design (CAD) techniques nowadays make it easier to establish a reproducible production line of such restorations. Full-coverage restorations are permanently fixed in the mouth by one of several kinds of cements, either acid based glass-ionomer, resin-based composite or self-adhesive resin cements. Cementation of the dental crown restoration establishes a crown-cement-tooth-complex (CCTC) intended to function as a single, durable unit. Although laboratory-fabricated crowns boast high mechanical strength and resistance to fatigue and wear, the CCTC is prone to failure. The highest frequency of failure is due to crown debonding (known as "loss of retention") or crown and core fracture. The reasons for these failures remain unclear. In summary, the longevity of dental full-coverage crown restorations remains an unresolved clinical challenge. Knowledge about the mechanical performance of the CCTC and how it changes over time due to aging processes is critical for tooth survival. So far, little evidence-based data is available regarding dynamic, time-dependent failure mechanisms of the CCTC. Non-destructive analyses of during simulated cycles of aging have been performed only to a very limited extent up to now. This is in part because models to predict failure as a function of geometry of the CCTC are lacking and approaches for failure prevention are still missing. This proposal combines the expertise of several complementary groups working across 3 institutes: PI Beuer brings his clinical experience and ongoing CAD/CAM dental-laboratory know-how relating to the fabrication of full-coverage tooth and implant supported crowns and their use in patients; PI Fleck contributes material science expertise in experimental testing as well as FE modelling of the mechanical behaviour of biological and engineering materials and structures and fatigue; PI Müller provides physics-based experience in high-energy X-ray computed tomography to bridge the clinical/experimental and simulation worlds and PI Zaslansky, speaker of FOR2804 within the dental clinic, brings his expertise in 2D and 3D high-resolution image and in situ strain analysis. Only by bundling such complementary expertise we can improve our understanding of the failure mechanisms of clinically-used CCTC structures. Jointly, the PIs will address the interdependence of macro- and micro-structural properties within the CCTC and mechanical performance alterations due to aging. We hypothesise that changes to the integrity of the cement layer due to aging are the major reason for failures of crown restorations. We postulate that damage accumulates with time, and that there may be early signs that correlate with later appearance of CCTC failures. Our objective, therefore, is to unravel how temporal changes in the cement layer structure influence the mechanical compliance and endurance of crown restorations. Specifically, for the CCTC, we will combine 3D imaging, lab and in silico testing to study changes in the cement layer during thermo-mechanical aging. We aim at discovering how aging-related structural changes are related to failure of dental crown restorations. A further aim is to generate reliable 3D lab-based data that can be used to describe and predict failure mechanisms of the CCTC.