Measurement of pH and calcium ions release from different calcium hydroxide pastes at different intervals of time: Atomic spectrophotometric analysis

AimTo evaluate the effect of different vehicles on pH and release of calcium ions from calcium hydroxide (CH) paste from apical third of root canals.Methods40 single rooted extracted human mandibular premolars were instrumented with RevoS files (MicroMega) up to ISO size 40. The teeth were divided into 4 groups on the basis of vehicle as follows: Group I - calcium hydroxide mixed with 2% chlorhexidine; Group II - calcium hydroxide mixed with propylene glycol; Group III - calcium hydroxide mixed with glycerine; and Control - calcium hydroxide mixed with double distilled water. Each group had two subgroups (n = 5) on the basis of the calcium hydroxide delivery. Subgroup A - calcium hydroxide paste placed with spiral filler (Lentulospiral) subgroup B - calcium hydroxide paste placed with flat wire filler (Paste Inject). pH and calcium ion release was evaluated at 24 h, 48 h, 7th day, 15th day and 30th day using a pH meter and atomic absorption spectrophotometer respectively.ResultsThe calcium release from various groups was highest for CH+glycerine (Group III) followed by CH+chlorhexidine (Group I), CH+propylene glycol (Group II) and CH+double distilled water (control). At all the intervals the differences in calcium ion release among the groups were statistically significant (p < 0.05), except on day 7. Delivery technique did not have a significant effect on calcium ion release. Highest pH values were recorded from CH+glycerine group at day 30 for both the delivery systems, however rise in pH from day 1 to day 30 were non-significant in all groups with both delivery systems.ConclusionDemonstrable changes in calcium ion release occurred from the calcium hydroxide mixed with various vehicles and CH+glycerine group showed the maximum calcium ion release at all intervals and highest pH day 30.