The influence of the restoration–tooth interface in light cured composite restorations: a finite element analysis

• Published in: Biomaterials 2001-12, Vol.22 (23), p.3097-3103
• Main Authors: Ensaff, H., O’Doherty, D.M., Jacobsen, P.H.
• Format: Article
• Language: English
• Subjects: Acrylic Resins; Biological and medical sciences; Composite Resins; Dental composite resin; Dental Restoration, Permanent; Finite element analysis; Light; Materials Testing; Medical sciences; Polymerisation shrinkage; Polyurethanes; Restoration–tooth interface; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Technology. Biomaterials. Equipments; Tooth
• ISSN: 0142-9612; 1878-5905
• DOI: 10.1016/S0142-9612(01)00058-8

This study examines the early shrinkage behaviour of dental composite resins, and in particular the interfacial stresses around the margins of a composite restoration. The development of stresses at the restoration–tooth interface can have a detrimental effect on the longevity of a restoration. The influence of this interface on the stress system generated in the tooth was examined using finite element analysis. The restoration–tooth interface was simulated using spring elements of varying spring constants ( k=1, 10 2, 10 4, 10 10 N/mm). Interfacial stresses varied from −0.15 to 0.42 MPa for a spring constant of 1 N/mm, and from −19 to 68 MPa for a spring constant of 10 10 N/mm. Correlations between stiffness at the restoration–tooth interface and higher shrinkage stresses due to restricted shrinkage were found. Interfacial failure at the upper and lower regions of the interface, as well as cuspal movements of the order of 2 μm were predicated for the model of the highest spring constant, 10 10 N/mm. The restoration–tooth interface modelled by the spring elements was seen to have a conclusive effect on the ensuing stress system, as well as the longevity of the restoration.