Effect of heat on the hardness of glass carbomer cement used in atraumatic restorative treatment

Abstract

This study aimed to evaluate the effect of heat treatment on the microhardness of two glass ionomer cements: EQUIA Forte (GC Corporation) and GCP Glass Fill (GCPDental). Material and methods: Twenty specimens of the two glass ionomer cements were prepared following the manufacturer’s instructions, and 10 specimens of each material received heat treatment with a light curing unit (Carbo LED lamp, GCP-Dental). After seven days of storage in distilled water at room temperature (23°C), the 40 specimens were submitted for Vickers microhardness test (microhardness HMV 2T). Five indentations were performed on each specimen with a load of 100g, with a 10 second penetration time. Results: For both materials, the average microhardness value were higher in the groups that did not undergo heat treatment, the group presenting with the highest microhardness value was EQUIA Forte (GC Corporation) without heat treatment (125.3), and the lowest value was found for GCP Glass Fill (GCP-Dental) with heat treatment (72.9). Conclusion: The heat treatment had no influence on the microhardness of the glass ionomer cements tested.