How Efficient are Chairside Conditioning Methods for Repair of All-ceramics?

*1567 How Efficient are Chairside Conditioning Methods for Repair of All-ceramics?*
M. ÖZCAN, University Medical Center Groningen, University of Groningen, Netherlands, L.F. VALANDRO, Federal University of Santa Maria, Brazil, and W. KALK, University Medical Center Groningen, University of Groningen, AV Groningen, Netherlands Objective: Although clinical studies are limited, fracture/chipping of all-ceramics is reported. The objectives of this study were 1-to determine the most effective surface conditioning protocol for the repair strength of a resin-composite to core-veneering ceramic and 2-to identify the failure modes. Methods: Disc shaped ceramic specimens (core1:3 mm, veneer ceramic2:1mm) were embedded in PMMA with the bonding surfaces exposed. After ultrasonic cleaning, specimens were randomly assigned to one of the following conditioning protocol (N=40/n=10 per group): Gr1:Hydrofluoric acid (HF)3+aluminiumtrioxide (50ľm)4+silane5, Gr2:Aluminiumtrioxide (50ľm)+HF+silane, Gr3:HF+silica-coating6 (30ľm SiOx)+silane, Gr4:Silica-coating+HF+silane. After adhesive application7, resin composite8 was bonded using polyethylene molds and light-polymerized. All specimens were tested after thermocycling (6.000 cycles, 5-55C). The shear bond strengths (SBS) of resin- composite to ceramics were measured (universal testing machine, crosshead speed: 1mm/min). Failure modes were identified using SEM (Kruskal-Wallis, Kolmogorov-Smirnov). Results: Gr3 demonstrated significantly higher results (MPa) (8.6ą2.6) than those of other groups (3.1ą3.5 - 3.2ą3) (p<0.001) (ANOVA, Bonneferroni, alpha=0.05). Failure types showed significant differences between groups (p=0.032), core and veneering ceramics (p<0.0005). No resin remnant and no fractures were observed in the core ceramic. Resin covered mainly <1/3 of the bonded area in Gr1 and 2, and >1/3 in Gr 3 and 4. Conclusions: Etching the veneer ceramic with HF gel, silicacoating the core followed by silanization resulted in the highest repair strength of the resin-composite tested. 1In-Ceram Zirconia, Vita. 2Vita VM7, Vita. 3Porcelain Etch, Ultradent. 4Korox, Bego. 5ESPE-Sil, 3M-ESPE. 6CoJet, 3M-ESPE. 7VisioBond 3M-ESPE. 8Quadrant Posterior, Cavex.
Seq #183 - Ceramics and Cements: Bond Strength 2:00 PM-3:15 PM, Friday, March 23, 2007 Ernest N. Morial Convention Center Exhibit Hall I2-J
Back to the Dental Materials: III - Ceramics and Cements Program Back to the IADR/AADR/CADR 85th General Session and Exhibition (March 21-24, 2007)
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