Effect of Universal Adhesive Etching Mode on Shear Bond Strength of Pulp Capping Materials to Deep Dentin

Objective: This study was aimed at investigating the shear bond strength (SBS) of composite to deep dentin with universal adhesive in total-etch (TE) and self-etch (SE) mode using different pulp capping materials. Methods: One hundred twelve sound human third molars were divided according to universal adhesives (All-Bond Universal and G-Premio Bond), etching modes (TE and SE), and pulp capping materials (TheraCal PT, TheraCal LC, and Lime-Lite). After sectioning the tooth 2 mm above and 3 mm below the CEJ, the liner, adhesive, and composite were applied. Specimens were tested for SBS using the universal testing machine at a crosshead speed of 1 mm/min after restoring with composite. Data were analyzed with three-way ANOVA (α = 0.05). Results: The highest and lowest SBS value was related to G-Premio bonding adhesive in SE mode using Lime-Lite (11.91 ± 0.77) and G-Premio bonding adhesive in SE mode using TheraCal PT (4.48 ± 0.83), respectively. Although the type of adhesive material did not have a significant impact on SBS values (p = 0.58), the mode of acid etching (p = 0.001) and the type of liner (p = 0.001) used were found to have a significant effect. Moreover, TE mode was associated with higher SBS values than SE mode. Conclusions: Using TE mode increased the SBS; in contrast, liners reduced the SBS of the composite to deep dentin. Moreover, other generations of adhesives and comparison with universal bonding should be done in future studies.