Ca(OH)2 has an antimicrobial effect through the dissociation of Ca2+, OH- ion and pH ideally
used as an intracanal medicament. Nanoparticle Ca(OH)2 has been successfully obtained from
natural limestone in Indonesia. Nanoparticle Ca(OH)2, aquades, propylene glycol (PG),
methylcellulose (MS) and barium sulfate (BS) formulations can affect the mechanism of action.
This study aims to determine the effectiveness of the Ca(OH)2 nanoparticle formula as an
intracanal medicament through the Ca2+, OH- ion release and pH at the evaluation on days 1, 7,
and 14. The method of this study was an experimental study consisting of two groups, the first
group is the nanoparticle Ca(OH)2 25%, aquades, PG 3%, MS 2% and BS 35% and Ca(OH)2
Calxipex II® (Nippon Sika-Yakuhin., Shimonoseki, Japan) as the control group. Samples were
inserted into polyethylene tubes and immersed with 10 mL of distilled water, incubated at 37°C and
100% humidity. Evaluation of Ca2+, OH- ion release and pH has done with a spectrophotometer
(Dirui DR-7000D, China) and a pH meter (Lutron/pH-207, Taiwan). The results showed the Ca2+
ion release in all groups increased to its peak on day 14 (11.29±0.196) mg/dL and (17.52±4,67)
mg/dL.
The pH levels of the nanoparticle Ca(OH)2 formula have the same pattern and are increased
until day 14. However, this is not the same as measuring OH ion release. The number of OH ions
released was highest on day 7 and decreased on day 14. There were significant differences
between the two study groups on the measurements of the Ca2+, OH- ion release and pH with
different day variables. The commercial Ca(OH)2 group demonstrated significantly higher levels of
Ca2+, OH- ion release and pH than the nanoparticle Ca(OH)2 group. This can occur due to several
factors that are affected, such as the solvent, powder-liquid ratio, particle size, and contaminations.