pH measurement of root canal sealers

The purpose of this study was to compare the surface pH level of three different type sealers after mixing at various time intervals in vitro, The cements were mixed according to the manufacturer's instructions, They were incubated to set in 100% humidity at 37 degrees C for 1 h, 24 h, 5 days, 8 days, 2 wk, 3 wk, 4 wk, 5 wk, and 7 wk, pH was calculated by a Twin pH meter, The pH levels of the three sealers were different at various time intervals (p < 0.0001), The resin-based cement had a acid pH level (pH < 7.0), The calcium hydroxide-based cement showed a higher alkalinity pH level (pH > 7.0), The zinc oxide-eugenol-based cement showed a similar pH level to the calcium hydroxide cement at the end of the measurement, We postulated that, in endodontic therapy when those healing is needed, the alkaline-based sealer is the choice.