[Variation, over time, in the pH of the materials used for pulpal-dentinal protection. A new measurement method]

A modern AmpHel pH-meter permits the easy determination of dental materials pH. This new instrument has allowed, analysing seven cements and two varnishes used for pulpodentinal protection, continuously to specify this important parameter's modifications in the long run. The results of this study, conducted for six hours after cement mixing or varnishes application, certified glass ionomer cements' (Ketac-Cem, Fuji-Ionomer II) strong acidity, even higher than well known zinc phosphates' acidity is. A cavity liner's (Tubulitec) pH from an initial value of 6.07 decreased to 5.04 at sixth hour. On the contrary, much lower were the acidity of a modified ZOE (Temrex) and the one of a cavity varnish (Copalite): both showed a physiological pH from the beginning of the test.