Shear bond strength between conventional composite resin and alkasite-based restoration used in sandwich technique: An in vitro study.

Aim: The success of layered restorations necessitates the utilization of an improved restorative material compatible with composite restorations. Therefore, in this line of research, the strength of adhesion of conventional resin-based dental composite to different filling materials was tested.

Materials and methods: Conventional composite resin was bonded to four restorative materials (Group I: conventional glass ionomer cement (GIC), Group II: resin-modified glass ionomer cement, Group III: flowable composite, and Group IV: Cention-N) received no surface treatment (Subgroup A: control), sandblasting using 50-µm aluminum oxide particles (Subgroup B), sandblasting and resin adhesive (Subgroup C), acid etch and resin adhesive (Subgroup D), or self-etch resin adhesive (Subgroup E). After 24 h, the strength of adhesion between the conventional composite resin and the other tested filling materials was estimated by using a universal testing machine and compared using one-factor analysis of variance and Tukey's method.

Results: The conventional GIC had the minimum values of adhesion strength while the flowable composite and Cention-N had the maximum values of adhesion strength (P < 0.05). The treatment of the used restorative materials with sandblasting and resin adhesive boosted the adhesion strength (P < 0.05). The surface treatment of GIC-based materials with either acid etch and resin bonding agent or self-etch resin bonding agent boosted the adhesion strength (P < 0.05).

Conclusion: Cention-N sandblasted and coated with resin adhesive before the application of conventional composite resin in layered restorations is a potential alternative to GIC-based restorations and flowable composite.