Endodontic access preparations were prepared in 48 intact extracted human premolars. The teeth were divided into 6 groups, including positive and negative control groups. After access preparation, cotton pellets were placed in the pulp chamber so that the space remaining for the restoration was 4 mm. After thermal cycling for 500 cycles (5°C-55°C), the teeth were immersed in 2 % methylene blue solution at neutral (pH = 7.0) in an incubator for leakage assessment. The teeth were sectioned, and the greatest depth of dye penetration was recorded. Marginal leakage was evaluated with a stereomicroscope.
Positive control sections exhibited complete dye penetration, and negative controls had none. In the experimental groups, the differences in the leakage scores of the Clip and Cavit-G groups and the other 2 groups were very marked. There were no statistically significant difference in marginal leakage between Cavit-G and Clip.
The new light-curing temporary material Clip seals against marginal leakage as effectively as Cavit when used as a temporary filling.