title: Impact resistance of crowned endodontically treated central incisors with internal composite cores.
abstract: The impact fracture resistance of crowned endodontically treated teeth with composite cores but without posts, that had either no coronal dentin remaining or a 1 mm dentin collar was compared to that of unrestored caries free teeth. The teeth were struck mid-labially to simulate a common trauma situation using a pendulum device and fracture resistance determined by calculation of absorbed energies. No significant difference was found between the intact teeth and the crowned root treated teeth with composite core and a 1 mm dentin collar. Crowned root treated teeth with a composite core but no coronal dentin had significantly reduced fracture resistance (p < 0.05). Teeth with the dentin collar mainly fractured obliquely from the buccal crown margin to a point coincident with the simulated alveolus, representing a clinical situation which would allow retention rather than extraction of the tooth.
authors.affiliation: School of Dentistry, University of Otago Dunedin, New Zealand.
authors.forename: P R
authors.initials: PR
authors.lastname: Cathro
authors.forename: N P
authors.initials: NP
authors.lastname: Chandler
authors.forename: J A
authors.initials: JA
authors.lastname: Hood
mesh_terms: D003442:Crowns; D003799:Dental Stress Analysis; D006801:Humans; D007180:Incisor / Q000503:physiopathology; D011176:Post and Core Technique; D014082:Tooth Fractures / Q000517:prevention & control*; D019553:Tooth, Nonvital / Q000503:physiopathology*