IADR Abstract Archives
Ceramic Intaglio Staining Effect On Bond Strength Of Luting Agent
Objectives: In order to obtain a natural aspect of dental ceramics on dark substrates, the application of a stain layer on the intaglio surface has been an option. However, there is limited data in how this technique can affect bond strength of luting agents to the intaglio. This study evaluated the effect of intaglio staining on the bond strength between e.max CAD blocks and resin luting agent.
Methods: Eighteen e.max CAD blocks were sectioned, polished and crystalized. Blocks were divided in half to allow experimental and control groups on the same block. The following groups were assigned (n=24): G1- One layer of stain (Characterization and glaze with shades), G2- 2 layers of stain; G3- Control (no stain). After the glaze, the surface was treated with 9% Hydrofluoric acid (20s), then cleaned with 35% phosphoric acid (30s), and ceramic primer applied (60s). A polyvynilsiloxane (PVS) template was used to obtain four resin cement rods for each specimen (2mm height; 0.8mm diameter) that were light-cured for 20s. After polymerization, the PVS template was removed and the specimens were stored in distilled water (24 h). Microshear test was performed with a 5-N load cell and tested under shear at 0.7 mm/min. Data was analyzed with non-parametric tests (Kruskal-Wallis and Mann-Whitney).
Results: The results showed that the staining of the intaglio negatively affected the microshear bond-strength (Mann-Whitney, p<0.0001). While the control group presented a mean of 14.2 (4.4) MPa, the G1 and G2 means were 3.5 (1.73) and 3.7 (2.1), respectively. No difference was observed between one or two staining layers (Mann-Whitney, p=0.84). While the majority of failure mode for the control group was adhesive, for the experimental groups most failures were cohesive within the stained layer.
Conclusions: The modification of the intaglio surface with characterization and glaze caused significantly reduction on the bond strength between the ceramic and the luting agent.
Methods: Eighteen e.max CAD blocks were sectioned, polished and crystalized. Blocks were divided in half to allow experimental and control groups on the same block. The following groups were assigned (n=24): G1- One layer of stain (Characterization and glaze with shades), G2- 2 layers of stain; G3- Control (no stain). After the glaze, the surface was treated with 9% Hydrofluoric acid (20s), then cleaned with 35% phosphoric acid (30s), and ceramic primer applied (60s). A polyvynilsiloxane (PVS) template was used to obtain four resin cement rods for each specimen (2mm height; 0.8mm diameter) that were light-cured for 20s. After polymerization, the PVS template was removed and the specimens were stored in distilled water (24 h). Microshear test was performed with a 5-N load cell and tested under shear at 0.7 mm/min. Data was analyzed with non-parametric tests (Kruskal-Wallis and Mann-Whitney).
Results: The results showed that the staining of the intaglio negatively affected the microshear bond-strength (Mann-Whitney, p<0.0001). While the control group presented a mean of 14.2 (4.4) MPa, the G1 and G2 means were 3.5 (1.73) and 3.7 (2.1), respectively. No difference was observed between one or two staining layers (Mann-Whitney, p=0.84). While the majority of failure mode for the control group was adhesive, for the experimental groups most failures were cohesive within the stained layer.
Conclusions: The modification of the intaglio surface with characterization and glaze caused significantly reduction on the bond strength between the ceramic and the luting agent.
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