Objective: The current study aims to compare the impact of invasive and non-invasive techniques on the microleakage of two fissure and pit sealants.
Materials and methods: The study included 84 first permanent molar teeth. Teeth were sorted into two groups (n=42) based on the sort of fissure sealant utilized: A1 was sealed with resin fissure sealant (helioseal F), and A2 was sealed with flowable composite fissure sealant (tetric flow). According to the fissure sealant preparation technique, each group was divided into two subgroups (n=21): B1 represents an invasive technique, and B2 represents a non-invasive technique (intact). Each subgroup was furtherly divided according to storage times into three classes (n=7): C1 (one week), C2 (one month), and C3 (three months). Teeth were thermocycled and stored. Then, Microleakage was investigated by immersing the teeth in a 5% methylene blue dye. Results: Gr-A2 recorded a higher leakage score mean value than the Gr_A1 group. The difference was statistically significant (p< 0.05). The Gr B1 group was observed to have a lower mean leakage score than the Gr B2 group (p< 0.05). The highest leakage score mean values were recorded after three months of storage followed by one-month storage, while the lowest leakage score mean values were recorded after one-week storage (p < 0.05). Conclusion: The used sealants failed to achieve completely leak-free conditions. Helioseal F sealant had the least amount of microleakage. Moreover, invasive techniques provide better marginal sealing. The least microleakage was recorded at one week, while the highest was three months.