Determination of setting time in cements based on hydroxyapatite and galactomannan extracted from Adenanthera pavonina L. seeds by the resonant cavity method compared to the Gilmore Needle method

ABSTRACT

The setting time of dental cements is an important clinical parameter, as it estimates the time available to carry out the post-cement treatment, which cannot be long or short. Currently, this parameter can be determined using the ISO 6876/2001 and ADA 57/2000 standards. These techniques use the Gilmore needle and perform only a superficial analysis to determine the setting time, and it is not possible to indicate whether the cement has completely dried. The objective of this work was to determine the setting time using the resonant cavity method of cements based on Hydroxyapatite (Hap) and galactomannan (Gal) extracted from Adenanthera pavonina L. seeds. Two compounds were prepared: HAG (75% HAp and 25% Gal by weight as solid phase and 0.30 mL of distilled water as liquid phase) and HAGJET (75% Hap, 2% by weight of Gal powder with 0.10 mL of commercial catalyst JET (methyl dimethyl methacrylate) p-toluidine) and 0.20 ml of distilled water). The solid phase in each material was dissolved in the liquid corresponding to each compound formed. The insertion of HAG and HAGJET cements generated a disturbance in the electric field due to the presence of free water in the sample, where this disturbance decreases as the cement hardens due to the evaporation of this free water. According to the results, the HAG cement had the longest setting time due to the absence of the chemical activator in its preparation, while the HAGJET cement, which had the activator in its processing, presented the lowest setting time in both techniques.

Keywords
Setting Time; Resonant Cavity; Dental Cement; Hydroxyapatite; Galactomannan