Surface hardness of CEM cement and cold ceramic cement across different pH settings

Objective: This study aimed to assess the surface microhardness of calcium-enriched mixture cement (CEM) and cold ceramic (CC) cement after being cured in environments with different pH values.Methods: Sixty maxillary canines were obtained. Their roots were cut below the cementoenamel junction (CEJ) to create root dentin blocks with a height of 3 mm. The internal space of the canal was then prepared with a Peeso reamer. The specimens were filled with either CEM (Group 1) or CC (Group 2) cement (n=30). The groups were further divided into three subgroups (n=10), each was wrapped in gauze soaked in one of the following solutions: A) distilled water (pH=7.4), B) buffered butyric acid (pH=4.4), or C) potassium hydroxide (pH=10.4). The samples were incubated at 37°C for one week. Afterwards, the Vickers surface microhardness of specimens was measured and compared between groups and subgroups using a two-way ANOVA (α=0.05).Results: The microhardness values of both cements showed significant differences depending on the environmental conditions (P<0.05). The highest microhardness was observed in the alkaline environment, with CC cement measuring 60.32 ± 3.16 and CEM cement measuring 53.57 ± 2.09. The microhardness of both materials reduced significantly in the acidic environment (P<0.05). CC cement demonstrated significantly higher surface microhardness than CEM cement in neutral and alkaline environments (P=0.001 for both), but the two groups showed comparable microhardness in the acidic environment (P=0.51).Conclusions: CC cement showed greater microhardness than CEM cement in neutral and alkaline environments. Both cements exhibit reduced hardness in the acidic condition.