title: In vitro fracture resistance and marginal adaptation of metallic and tooth-coloured post systems.
abstract: The aim of this in vitro study was to compare the fracture resistance and marginal adaptation of all-ceramic incisor crowns with all-ceramic posts, glass-fibre-reinforced posts and titanium posts as well as a control without any post. Three groups of eight maxillary incisors were restored with an all-ceramic post, a fibre-reinforced composite (FRC) post, a titanium post and a further group was restored without posts. Composite cores were provided and all-ceramic crowns were adhesively luted. After artificial ageing, the fracture resistance of the restored teeth was determined. The marginal adaptation of the restorations at the interfaces between cement-tooth and cement-crown was evaluated with scanning electron microscopy using replica specimen before and after ageing. The restored teeth without posts [270N (235/335)] showed no significantly different fracture strength compared with teeth with the titanium system [340N (310/445)]. The all-ceramic posts [580N (425/820)] and the FRC posts [505N (500/610)] both provided a significant higher fracture resistance than the teeth without posts. Prior to ageing, all materials showed <5% separation at the margins cement-tooth or cement-crown ('marginal gap'). After ageing, the interfaces of all systems deteriorated to values between 6 and 14% marginal gap. The greatest marginal gap was found with the titanium system (14%) at the interface cement-crown and with the all-ceramic posts (12%) at the transition between cement-tooth. Regarding fracture resistance and the marginal adaptation, the all-ceramic and FRC posts may be considered as an alternative to the commonly used titanium post restorations.
authors.affiliation: Department of Prosthetic Dentistry, University Clinics, Regensburg, Germany. martin.rosentritt@klinik.uni-regensburg.de
authors.forename: M
authors.initials: M
authors.lastname: Rosentritt
authors.forename: M
authors.initials: M
authors.lastname: Sikora
authors.forename: M
authors.initials: M
authors.lastname: Behr
authors.forename: G
authors.initials: G
authors.lastname: Handel
mesh_terms: D002484:Cementation; D003442:Crowns; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis / Q000379:methods; D005898:Glass; D006801:Humans; D066298:In Vitro Techniques; D007180:Incisor / Q000648:ultrastructure; D008422:Materials Testing / Q000379:methods; D008855:Microscopy, Electron, Scanning; D011176:Post and Core Technique; D013314:Stress, Mechanical; D014025:Titanium; D014082:Tooth Fractures / Q000503:physiopathology / Q000517:prevention & control*
chemical_list: C009753:fiberglass; D014025:Titanium