[PH changes of different cements].

Some properties are required in dental cements used in fixed restorations. One of them is the acidic characteristic of the material since (OH)- ions released during the setting phase may have undesirable effects on the pulp. In this study three different luting cements were tested regarding to their PH values during setting reaction and was found that cements used caused PH changes. Acidity of cements had changed considerably depending upon time and it was determined that PH values of three cements decreased in the period of 24 hours.