Five EO-containing solutions were manipulated according to the manufacturer’s recommendations; in addition, artificial saliva and 0.3% citric acid were respectively used as positive and negative controls (Table 1 ).
A total of 10 mL of each solution was added to a glass beaker and the pH value at 25°C was measured by a benchtop electrode previously calibrated with standard solutions (pH 4.01, 7.00, and 10.00). The electrode was washed with distilled water between each one of the three measurements.
Aliquots of 0.1 M sodium hydroxide were added to 10 mL of each solution (eight samples per group), and the total base volume (µL) of base needed to raise the initial pH to 7 was recorded. The TA was not determined for solutions with initial pH above 7 or neutral.
A total of 0.5 mL of each EO-containing solution was mixed with 0.5 mL of 10% (v/v) nitric acid (six samples per group), sieved with filter paper, diluted in 1:10 deionized water, and placed into polyethylene bottles (Medeiros et al., 2020 (link)). Ca2+, K+, and Na+ ions were quantified by using inductively coupled plasma optical emission spectrometry (ICP-OES) under axial configuration, equipped with an automatic sampling system (Vista-MPX CCD Simultaneous; Varian, Mulgrave, Australia), and operating conditions determined by specific software (ICP Expert Vista; Varian).
A total of 10 mL of each solution was added to a glass beaker and the pH value at 25°C was measured by a benchtop electrode previously calibrated with standard solutions (pH 4.01, 7.00, and 10.00). The electrode was washed with distilled water between each one of the three measurements.
Aliquots of 0.1 M sodium hydroxide were added to 10 mL of each solution (eight samples per group), and the total base volume (µL) of base needed to raise the initial pH to 7 was recorded. The TA was not determined for solutions with initial pH above 7 or neutral.
A total of 0.5 mL of each EO-containing solution was mixed with 0.5 mL of 10% (v/v) nitric acid (six samples per group), sieved with filter paper, diluted in 1:10 deionized water, and placed into polyethylene bottles (Medeiros et al., 2020 (link)). Ca2+, K+, and Na+ ions were quantified by using inductively coupled plasma optical emission spectrometry (ICP-OES) under axial configuration, equipped with an automatic sampling system (Vista-MPX CCD Simultaneous; Varian, Mulgrave, Australia), and operating conditions determined by specific software (ICP Expert Vista; Varian).