title: Tunnel or saucer-shaped restorations: a survival analysis.
abstract: The aim of the present effectiveness trial was to compare the survival of restorations placed in saucer-shaped cavities to that of restorations placed in tunnel preparations. Ten operators placed a total of 85 tunnel and 97 saucer-shaped restorations. The dentinal part of the tunnel was restored by resin-modified glass ionomer cement. The remaining part of the tunnel was restored by composite resin using an adhesive technique. Composite resin was used to restore the saucer-shaped cavities. The restorations were assessed clinically and radiographically for up to 79 months, with a mean observation time of 28.8 months for tunnel, and 30.3 months for saucer-shaped restorations. The survival proportion of the tunnel restorations was 46%, and the survival proportion for the saucer-shaped restorations was 76%. A main reason for failure of the tunnel restorations was fracture of the marginal ridge (24% after 24 months). Caries development in relation to the restoration was significantly higher for tunnel restorations compared with saucer-shaped restorations (41 and 19%, respectively, after 24 months). There was no difference between the two types of restoration in marginal deterioration and caries progression in the neighboring tooth (40% after 24 months). Based on findings from the present study, it is suggested that saucer-shaped restorations should be preferred for tunnel restorations in small- and mid-sized cavities.
authors.affiliation: Department of Dental Pathology, Operative Dentistry and Endodontics School of Dentistry, Faculty of Health Sciences, University of Aarhus, Vennelyst Boulevard 9, Aarhus, 8000, Denmark. ph-b@odont.au.dk
authors.forename: P
authors.initials: P
authors.lastname: Hörsted-Bindslev
authors.forename: B
authors.initials: B
authors.lastname: Heyde-Petersen
authors.forename: P
authors.initials: P
authors.lastname: Simonsen
authors.forename: V
authors.initials: V
authors.lastname: Baelum
mesh_terms: D000293:Adolescent; D001641:Bicuspid / Q000473:pathology; D002648:Child; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003731:Dental Caries / Q000209:etiology; D003737:Dental Cavity Preparation / Q000145:classification* / Q000706:statistics & numerical data; D018772:Dental Marginal Adaptation; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent / Q000145:classification* / Q000706:statistics & numerical data; D003804:Dentin / Q000473:pathology; D017220:Dentin-Bonding Agents / Q000737:chemistry; D018450:Disease Progression; D005500:Follow-Up Studies; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D008963:Molar / Q000473:pathology; D019279:Resin Cements / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013499:Surface Properties; D016019:Survival Analysis; D015040:Zirconium / Q000737:chemistry
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; D005899:Glass Ionomer Cements; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; C083568:Z100 composite resin; C067790:Vitrabond; D012822:Silicon Dioxide; D015040:Zirconium