Bonding of CAD/CAM lithium disilicate restorations with regular and flowable composite resin with and without wetting resin

Assess the effect of applying a low viscosity resin before placing ceramic restoration with two different luting agent.

Twenty slices from IPS e.max CAD (Ivoclar Vivadent) were fired and assigned to 5 treatment surface groups; E: hydrofluoric acid (HF); E/S: HF-etching?+?silane (20?s); E/S+: HF-etching?+?silane (60?s); S: silane (20?s); S+: silane (60?s). Before building the cylinder with regular or flowable composite resin for the SBS test, half of each treatment surface group received adhesive (Optibond FL bottle #2), and the other half no adhesive. The SBS test was performed after 24?h. Statistical analysis was performed using multifactorial analyses of variance Two-way ANOVA. The Tukey HSD test was used to test the average values of all groups. The significance level adopted in all analyses was?≤?0.05 (p?<?0.05).

Groups E/S and E/S+, with flowable?+?adhesive and E/S with regular composite resin?+?adhesive, showed the highest SBS values (22.05, 18.91 and 21.06?MPa respectively), followed by group E with or without adhesive, for both luting agent. The lowest bond strength was observed when the silane was applied alone, independent of the adhesive coat and luting agent (0.65–5.55?MPa). When the adhesive was omitted, flowable presented high bond strength compared to composite resin in groups ES and ES+.

The low viscosity resin in the etched and silanized ceramic surface is important to obtain high SBS values.