A comparative evaluation of calcium ion release and pH change using calcium hydroxide nanoparticles as intracanal medicament with different vehicles - An in vitro study

Context: Nano-calcium hydroxide (NCH) has been proven to have several advantages over normal calcium hydroxide, supporting in its possible use as an intracanal medicament. Aim: The aim is to evaluate and compare calcium ion release and pH change using NCH with different vehicles as intracanal medicament. Subjects and Methods: Sixty freshly extracted premolars were decoronated at the cementoenamel junction level and the length was standardized. Canals were enlarged to F3 size using protaper rotary system. The samples were divided into three groups (n = 20), namely NCH + distilled water (Group 1), NCH + propylene glycol (Group 2), and NCH + chitosan (CT) (Group 3). Each sample was suspended in 6 ml of distilled water using silicone putty with only the apical third of the roots immersed. The pH and calcium ions were assessed at 24 h, 7 days, 15 days, and 30 days using a pH meter and ultraviolet spectrophotometer, respectively. Statistical Analysis: Comparison of mean calcium release and pH change was made using Kruskal-Wallis ANOVA with post-hoc Dunn's test. The level of significance was set at 5%. Results: A significant difference was seen in the calcium ion release and pH change among the three groups at 24 h, 7 days, 15 days, and 30 days. Conclusions: NCH mixed with propylene glycol showed alkaline pH and adequate release of calcium ions till 30 days. NCH mixed with CT exhibited a high pH at the end of 30 days. Both combinations proved their efficacy as intracanal medicaments.