Improved bonding of zirconia substructures to resin using a "glaze-on" technique.
OBJECTIVE
To investigate the influence of applying thin intermediary coatings of acid-etchable glasses on the shear bond strength between a methacrylate resin based cement and an yttria-stabilized zirconia dental ceramic substrate.


METHODS
The upper and lower surfaces of 110 sintered yttria-stabilised tetragonal zirconia polycrystalline disc-shaped specimens were polished using sequential grades of Silicon Carbide, then air-abraded with 25 μm diameter alumina particles. Specimens were randomly allocated to 11 groups (A-K) (n=10), group A acting as control. The upper surface of Group A specimens was subjected to a tribochemical coating regime (CoJet, 3M ESPE). Five glazing ceramics were applied and fired according to the manufacturer's recommended firing regime. The glaze was etched with 10% HF acid and all specimens coated with a silane primer. Two differing storage regimes were employed (wet storage vs thermocycling). Shear bond strength testing specimens were created by cementing resin-based composite cylinders to the centre of the prepared ceramic surface using Rely-X Unicem (3M ESPE) resin based cement. Shear bond strength testing was performed and load at failure recorded.


RESULTS
A factorial analysis of variance at a 95% significance level demonstrated that all glazing techniques resulted in a significant increase in the shear bond strength compared with using the resin based cement alone (P<0.01), with the different glazing ceramics resulting in significant differences in mean shear bond strength (P=0.008). The differences were a function of the storage state (wet storage vs thermocycling (P=0.013)).


CONCLUSIONS
The glazing techniques used in the current investigation resulted in a significantly enhanced shear bond stress to the resin based cement when compared with the current 'gold standard' - tribochemical coating.
General Dental Practitioner, Leeds, UK.
Peter
P
Everson
Owen
O
Addison
William M
WM
Palin
F J Trevor
FJ
Burke
D000134:Acid Etching, Dental / Q000379:methods; D000537:Aluminum Oxide / Q000737:chemistry; D017554:Carbon Compounds, Inorganic / Q000737:chemistry; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding / Q000379:methods*; D045662:Dental Etching / Q000379:methods; D003764:Dental Materials / Q000737:chemistry*; D003776:Dental Porcelain / Q000737:chemistry; D003799:Dental Stress Analysis / Q000295:instrumentation; D005898:Glass / Q000737:chemistry*; D006358:Hot Temperature; D006801:Humans; D006858:Hydrofluoric Acid / Q000737:chemistry; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D017655:Silicon Compounds / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D014867:Water / Q000737:chemistry; D015019:Yttrium / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
D017554:Carbon Compounds, Inorganic; D020099:Coated Materials, Biocompatible; D003188:Composite Resins; D003764:Dental Materials; D008689:Methacrylates; C483701:Rely X Unicem; D019279:Resin Cements; D017655:Silicon Compounds; C483027:vitadur alpha; C499362:yttria stabilized tetragonal zirconia; D014867:Water; D003776:Dental Porcelain; D015019:Yttrium; D015040:Zirconium; D000537:Aluminum Oxide; D006858:Hydrofluoric Acid; C022088:silicon carbide