Bond strength evaluation of two bioactive liners and glass ionomer cement, bonded to resin composite: A comparative study

الملخص

Abstract
Aims: The mechanical properties of cements, as well as their adhesive properties, are important factors that influence the durability of restorations in the oral cavity. So the aim of this study is to compare and evaluate the bond strength of resin composite to underlying bioactive materials (Biodentine & Therecal) and conventional Glassionommer cement using single bond adhesive system and characterizing their failure modes with
(10X magnification). Materials and Methods: 30 acrylic blocks
containing a central hole with a 5mm diameter and a 2mm height were prepared and divided into three groups of 10 samples each based on the liner used as Group A Biodentine (BD), Group B Therecal (TLC), and Group C chemical cure glassionomer cement (GIC). The resin composite of 4 mm diameter and 2 mm height was then bonded to each sample using universal adhesive. Shear bond strength (SBS) analysis was performed at a cross-head speed of 0.5 mm/min.
Statistical Analysis: Statistical analysis was performed with one-way analysis of variance (ANOVA) and least significant difference (LSD) tests were P > 0.05 (Non-significant), P<0.05 (significant), P < 0.001 (highly significant) using Statistical Package for the Social Sciences (SPSS) version 19.
Results: The results showed that the highest mean of SBS was in group B (TLC) (21.79 Mpa). While the lowest mean of SBS was scored by group A (BD) (6.5490 Mpa). Both group B (TLC) and group C(GIC) showed a very high significant difference (p = 0) more than group A (BD) while group B(TLC) showed a significant difference (p = 0.001) higher than group C (GIC). The observed mode of failure were predominately cohesive in group A (BD), in group B (TLC) were adhesive and mixed while group C (GIC) were shown cohesion and a mixed mode of failure
Conclusions: This present study concludes that;
Both TLC and GIC showed adequate bond strength to be used immediately as a direct liner beneath composite resin in single appointment. While newly set BD showed weak bond strength with composite, which mean it is better to use it in two-stage filling procedure.