The influence of cavity shape on the stresses in composite dental restorations: a finite element study.
Dental restoration adhering to the cavity exhibits fundamentally different load transfer mechanisms from non-adhering restorations. It is therefore questionable that traditional cavity designs are optimal from a purely mechanical point of view when working with composite materials. Drawing from general engineering experience, it can be hypothesised that smooth, well rounded designs with bevelled margins are superior. A finite element model is used in the present investigation to determine the stress field in four different cavity designs as it develops during the curing of the restoration. The results show that a significant reduction of the stress along the adhesive interface between the tooth and the restoration can be achieved through the use of a rounded cavity shape. They also show that the adoption of bevelled margins leads to a reduction of the stress concentration at this location. These results are confirmed by a set of experimental results published in the literature. It is concluded that adhering restorations will perform better from a mechanical point of view if an appropriate cavity shape is selected.
Biomechanics Research Unit, Dental Health and Biological Sciences, University of Wales College of Medicine, Cardiff Medicentre, Heath Park, Cardiff CF14 4UJ, Wales, UK.
Pierre
P
Hubsch
John
J
Middleton
Jeremy
J
Knox
D003188:Composite Resins / Q000737:chemistry*; D003198:Computer Simulation; D001840:Dental Bonding; D003731:Dental Caries / Q000503:physiopathology / Q000601:surgery; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent / Q000295:instrumentation / Q000379:methods*; D004548:Elasticity; D020342:Finite Element Analysis; D006801:Humans; D066298:In Vitro Techniques; D008954:Models, Biological; D013314:Stress, Mechanical; D014070:Tooth / Q000503:physiopathology* / Q000601:surgery; D014783:Viscosity
D003188:Composite Resins