Which one of the following is major disadvantage of Rickerts sealer:
Rickert's sealer also known as Kerr pulp canal sealer developed in the year 1931 by the scientist Rickerts as an alternative to chlorpercha. It is an example of a zinc oxide eugenol based sealer. It comes in the powder liquid form. Following is the composition of Rickert's sealer:
Composition of Rickert's sealer:
|Zinc oxide - 41.21 parts||Oil of cloves - 78 parts|
|Precipitated silver - 30 parts||Canada balsam - 22 parts|
|White resin - 16 parts|
|Thymol iodide - 12.79 parts|
Indications of Rickert's sealer:
1. Vertical condensation of warm gutta-percha when a large bulk of sealer is needed
2. When lateral canals are anticipated, for silver points.
1. It has excellent lubrication.
2. Has a working time of 30 minutes.
3. The recommended powder liquid (P:L) ratio is 1:1.
4. It has a germicidal action.
Method of mixing:
Powder and liquid are mixed with a heavy spatula until homogeneity is obtained. The mixture that is obtained after spatulation apperars slightly granular due to the presence of silver.
Disadvantages of Rickert's sealer:
1. Due to the presence of silver, it stains the tooth structure. So this sealer has to be removed from the crown area of the tooth.
2. It has a shorter working time.