Fracture Resistance of Glass Ceramic Crowns With Different Cementation Modes
Objectives: To analyze the influence of conventional cementation (CC) and adhesive bonding (AB) on the fracture resistance of single molar glass ceramic crowns during a simulated five year oral service.
Methods: The materials under investigation were single molar glass ceramic crowns (VITA SUPRINITY, Vita Zahnfabrik, Bad Säckingen, Germany). Ceramic-wise tooth preparation of freshly extracted human molars and CAD/CAM crown preparation was performed according to manufacturer’s instructions. The crowns (n = 8) were conventionally cemented (Ketac Cem, 3M ESPE, Seefeld, Germany) or adhesively bonded (Variolink II / Syntac classic, Ivoclar-Vivadent, Schaan, Liechtenstein). During a combined thermal cycling and mechanical loading (TCML) five years of oral service was simulated (6000x5°C/55°C, 2 min. each cycle, H20 dist., 1.2x106 force á 50N). Resilience of the human periodontium was simulated by root coating with a 1 mm polyether layer (Impregum, 3M ESPE, Seefeld, Germany). Fracture force was determined by mechanically loading the crowns to failure in a universal testing machine (Zwick Roell, Ulm, Germany). The force was applied on the center of the crowns using a steel ball (Ø = 12 mm, crosshead speed = 1mm/min) with a 1 mm foil inserted between crown and ball. The failure determination was set to a 10% loss of the maximum loading force or acoustic signal (crack).
Results: Fracture values ranged between 1888N +/-585 for CC and 2612N +/-853 for AB.
Conclusions: The fracture forces of CC crowns are sufficiently high in comparison to literature data on human teeth with fracture values between 2000-2500N. The fracture forces of AB crowns are in a range, where no restrictions should be expected for clinical application. Also, in relation to maximum in-vivo loadings of about 800-1000N no restrictions in strength should be expected for either CC or AB crowns in clinical application.
Division: IADR/AADR/CADR General Session
Meeting:2015 IADR/AADR/CADR General Session (Boston, Massachusetts) Location: Boston, Massachusetts
Year: 2015 Final Presentation ID:3694 Abstract Category|Abstract Category(s):Dental Materials 3: Ceramic-based Materials and Cements
Authors
Just, Benjamin
( VITA Zahnfabrik
, Bad Säckingen
, Germany
)
Goediker, Michael
( VITA Zahnfabrik
, Bad Säckingen
, Germany
)
Fischer, Jens
( VITA Zahnfabrik
, Bad Säckingen
, Germany
; Institute for Material Sciences and Engineering, University Hospital of Dental Medicine, University of Basel
, Basel
, Switzerland
)
Rosentritt, Martin
( UKR University Hospital Regensburg, Department of Prosthetic Dentistry
, Regensburg
, Germany
)
Financial Interest Disclosure: B. Just, M. Gödiker, and J. Fischer are employees of VITA Zahnfabrik, Bad Säckingen, Germany. M. Rosentritt has no significant affiliation with VITA Zahnfabrik.