The purpose of this study was to compare the surface pH level of three
different type sealers after mixing at various time intervals in vitr
o, 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 calcul
ated by a Twin pH meter, The pH levels of the three sealers were diffe
rent at various time intervals (p < 0.0001), The resin-based cement ha
d a acid pH level (pH < 7.0), The calcium hydroxide-based cement showe
d a higher alkalinity pH level (pH > 7.0), The zinc oxide-eugenol-base
d 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.