IADR Abstract Archives
Effect of Surface Treatment of Lithium-Disilicate: Flexural and Shear-bond Strength
Objectives: The objectives of the study was to measure the effect of different surface treatments on the biaxial flexural strength (BFS) and shear-bond strength (SBS) of lithium disilicate (LD).
Methods: The lithium disilicate (IPS e.max® CAD HT/A1) discs (Dimensions:4.0±0.2mm/1.2±0.2mm) for BFS were milled with CEREC MCXL (Sirona) milling machine. The prepared specimens were crystallized using the Programat CS furnace/Program-3 (Ultra-Fast firing cycle: 14:50minutes). The specimens for SBS were prepared by sectioning, crystallizing and mounting LD blocks. Specimens (n=10) were randomly distributed to six experimental groups (1-6) as functions of surface finish and treatment (Table-1). Specimens of Groups: 1 and 6 were treated with Monobond® Plus (MP), Groups: 2 and 4 were acid etched with hydrofluoric acid (HF)/(4.5%) 20s and 60s respectively followed by MP application and Groups: 3(1minute) and 5(1+1minutes) were treated with self-etching ceramic primer (Monobond® Etch and Prime (MEP)). The SBS specimens were secured in Ultradent Jig, resin cement (Variolink® Esthetic DC (Neutral)) was condensed in the insert (Ø2.38mm) and was light cured (Bluephase G2/20s). Specimens were stored in the incubator (37°C/100% humidity) for 24 hours. Instron Universal testing machine was used to determine BFS and SBS. Data was analyzed by One-way Analysis of Variance (ANOVA) and Tukey’s HSD post-hoc test (α=0.05).
Results: Table-1: Experimental groups and biaxial flexural strengths (MPa)/(Mean ± SD). Groups showing different superscripts were significantly different (α=0.05).
Conclusions: Within the limitation of this study, over-etching of LD with HF (Group-4) significantly decreased BFS and SBS. The use of MEP appeared technique tolerant and no significant decrease in BFS and SBS was observed compared to other experimental groups.
Methods: The lithium disilicate (IPS e.max® CAD HT/A1) discs (Dimensions:4.0±0.2mm/1.2±0.2mm) for BFS were milled with CEREC MCXL (Sirona) milling machine. The prepared specimens were crystallized using the Programat CS furnace/Program-3 (Ultra-Fast firing cycle: 14:50minutes). The specimens for SBS were prepared by sectioning, crystallizing and mounting LD blocks. Specimens (n=10) were randomly distributed to six experimental groups (1-6) as functions of surface finish and treatment (Table-1). Specimens of Groups: 1 and 6 were treated with Monobond® Plus (MP), Groups: 2 and 4 were acid etched with hydrofluoric acid (HF)/(4.5%) 20s and 60s respectively followed by MP application and Groups: 3(1minute) and 5(1+1minutes) were treated with self-etching ceramic primer (Monobond® Etch and Prime (MEP)). The SBS specimens were secured in Ultradent Jig, resin cement (Variolink® Esthetic DC (Neutral)) was condensed in the insert (Ø2.38mm) and was light cured (Bluephase G2/20s). Specimens were stored in the incubator (37°C/100% humidity) for 24 hours. Instron Universal testing machine was used to determine BFS and SBS. Data was analyzed by One-way Analysis of Variance (ANOVA) and Tukey’s HSD post-hoc test (α=0.05).
Results: Table-1: Experimental groups and biaxial flexural strengths (MPa)/(Mean ± SD). Groups showing different superscripts were significantly different (α=0.05).
Conclusions: Within the limitation of this study, over-etching of LD with HF (Group-4) significantly decreased BFS and SBS. The use of MEP appeared technique tolerant and no significant decrease in BFS and SBS was observed compared to other experimental groups.
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