Does simplification signify compromise? Evaluation of different universal adhesives on shear bond strength: in vitro...

Universal adhesives are widely used in the field of dental prosthetics owing to their broad applicability and clinical convenience. This study aims to evaluate the bonding performance of four adhesives on zirconia and resin material surfaces.

The shear bond strength (SBS) test results of four adhesives including Single Bond Universal Adhesive (3M1), Scotchbond™ Universal Plus Adhesive (3M2), PALFIQUE UNIVERSAL BOND (TK1) and BONDMER Lightless II (TK2) were studied (n = 10 per adhesive per storage condition) under three storage conditions: constant-temperature water storage at 37 °C for 24 h, 5,000 thermal cycles, and 10,000 thermal cycles. Three-way ANOVA, Tukey HSD test, and Games-Howell test were performed on the outcome data (α = 0.05). The Adhesive Remnant Index was used to evaluate the debonding condition between resin and zirconia surfaces.

All four groups exhibited acceptable bond strength measured at 24 h in a 37 °C constant-temperature water bath and significant differences were observed among the four groups (p < 0.05). After thermal cycling, the bond strength of all groups showed significant decline, with only TK1 yielding detectable data. Three-way ANOVA results indicated that all factors-storage conditions (p < 0.001), brands (p < 0.05), and generations (p < 0.05)-exerted significant effects on SBS. At the same time, significant differences were observed between the interaction among the three factors (p < 0.001).

The bonding performance of universal adhesives of different generations and brands is material-dependent. After 5,000 thermal cycles, the SBS differed significantly among brands and generations of adhesives, with TK1 exhibiting better performance in this study. Technological advances have introduced user-friendly products with simplified application procedures. However, clinicians should adopt an evidence-based perspective and focus on clinical effect and experimental data of materials.