In vitro release of hydroxyl ions from calcium hydroxide gutta-percha points

In endodontic practice, calcium hydroxide is widely used for a number of reasons associated with its high pH. The purpose of the present study was to determine in vitro the alkalizing potential of newly introduced calcium hydroxide gutta-percha points that are proposed for temporary filling of root canals. The materials tested were: calcium hydroxide gutta-percha points; chemical pure calcium hydroxide powder mixed with distilled water; and Reogan rapid, a nonsetting calcium hydroxide preparation. The materials were placed into dialysis tubing and transferred into plastic vials containing bidistilled water. Measurements were taken by a digital pH meter after 10, 20, and 30 s; 1, 15, and 30 min; and 1, 2, 3, 24, 48, 72, 96, and 120 h. The calcium hydroxide containing gutta-percha points showed a significantly lower alkalizing potential than Reogan rapid and calcium hydroxide mixed with distilled water (p < 0.05).