Introduction: The high viscosity Bulk-Fill composite (Tetric N ceram) and high viscosity glass ionomer cement (Equia Forte GIC) are the most used materials in class II cavities of primary molars. They have the advantages of being placed in a single layer of 4mm and therefore allow better ergonomics and speed of use. Until now, we find failures of restorations at the level of class II cavities of temporary teeth and many authors have tested the role of the bevel in improving the mechanical strength of restorations. Objectives: The objectives of this study are: to test the role of the bevel in improving the fracture resistance of Bulk Fill composite restorations versus GIC of class II restorations in primary molars, and to test which material has better resistance to fracture. Methods: One hundred temporary extracted molars are collected and randomly divided into four groups: Group I (non-beveled) and II (beveled) filled with Equia forte. Group III (non-beveled) and IV (beveled) filled with Bulk Fill Ivoclar Tetric N Ceram. The specimens were subjected to thermocycling from 5 to 55° for 10000 cycles. After artificial aging, an axial loading at a speed of 1 mm/min was applied until the specimens fractured. Results: The statistical analysis reveals the following: an average of 442.2 N for group I and 498.80 N for group II. Thus, no statistical difference was observed between the groups restored with Equia Forte (p-value>0.05). Whereas, the resistance to fracture for groups III (901.80N) and IV (2438.33N) with a p-value<0.001 so there is significant difference between the two groups. Conclusions: The bevel improves the fracture resistance of the BulkFilll Ivoclar restorations. Whereas, it does not influence the fracture resistance of the Equia Forte group. Bulk Fill Ivoclar Tetric N ceram has better resistance to fracture than Equia Forte GIC restorations.
Read full abstract