Potassium-Releasing Ability of Temporary Cement on Dentine

Objectives: To study potassium-releasing ability of temporary cement with potassium nitrate and influence factors. Methods: A total of 80 freshly extracted bovine lower incisors were randomly and equally divided into 16 groups and all the roots and pulps were removed. A cavity was prepared in the labial surface of the crown. The pulp chamber was connected and bonded to an organic glass tube. Distilled water was filled into the tube to mimic pulpal tissue pressure. The 0%, 5%, 15%, or 25% KNO₃ temporary cement (KTC) was filled into cavities of different group teeth respectively. Potassium concentrations in pulp chambers were measured at 6h, 24h, 7d, and 14d. The two-way ANOVA was used for statistic analysis. Results: The potassium concentration in pulp chamber rose with the increase of the application time and the percentage of KNO₃ in temporary cement. The percentage of KNO₃ in temporary cement, the application time, and their interaction all had significant influence on the potassium concentration in the solution of the pulp chamber (P<0.01). Conclusions: The KNO₃ temporary cement has the ability to release potassium ion constantly, and potassium ion can resist the outward dental fluid and diffuse into the pulp chamber. The higher the concentration of KNO₃ in temporary cement is, the stronger potassium-releasing ability temporary cement has.