Objectives: To evaluate in vitro the coronal leakage of endodontically treated teeth sealed with temporary restorative materials with or without coating sealants, and subjected to brushing and thermocycling.

Materials and Methods: One hundred two extracted human premolars and molars, were endodontically accessed, and restored with 3 types of temporary restorations: 1. Cavit (3M ESPE), 2. Ketac Molar (3M ESPE), 3. Riva Light Cure GlC (SDI). Each type of restoration had one subgroup with a coating (Cavit-Ketac Glaze, Ketac Molar- Ketac Glaze, Riva Light Cure GIC -- Riva Coat) and the other without coating. Restored teeth were placed in artificial saliva at 37°C for 24 hours. Teeth were divided into 3 treatment subgroups: Group A: No treatment, soaked at 37° C artificial saliva; Group B: Teeth underwent thermocycling; Group C: teeth underwent both thermocycling and brushing. Thermocycling included 500 cycles between 5°C to 55°C. Tooth brushing was simulated in a brushing machine using 190g weight applied to 16,800 linear strokes. The control group was not exposed to thermocycling or brushing. Leakage was detected by immersion of specimens in 2% methylene blue dye for 24 hours. Specimens were epoxy embedded and sectioned longitudinally. The leakage scores were evaluated from photographs by longitudinal dye penetration depth scored 0 for no leakage and 4 for maximum leakage to the bottom of restoration. Statistical analysis was done to examine the effect of coating and post-treatment on leakage scores.

Results: All tested temporary restorative materials with coating had lower leakage than without coating in all experimental groups.

Conclusions: The leakage of temporary restorative materials can be reduced by surface coating, however, thermocycling and brushing treatment can still generate some leakage.