Comparative evaluation of microleakage of four restorative materials using confocal laser scanning microscopy: an in vitro study.

Objective: Understanding the sealing ability of restorative materials to prevent microleakage and its consequent complications-such as secondary caries, postoperative sensitivity, and restoration failure-is imperative in clinical dentistry. This study aims to compare the microleakage performance of four restorative materials-bioactive composite resin (Activa Pronto), alkasite restorative (Cention N), compomer (Dyract Flow), and glass ionomer cement (Type 2 GIC)-in Class V cavities of extracted premolar teeth.

Materials and methods: Forty non-carious, intact premolar teeth were selected and prepared with standardized Class V cavities. The teeth were randomly assigned to one of four groups (n = 10) and restored with the respective materials. The restorations underwent thermocycling, followed by microleakage testing using rhodamine dye. Confocal laser scanning microscopy (CLSM), a technique that provides superior depth resolution and three-dimensional visualization of microleakage, was used to assess dye penetration at the tooth-restoration interface. Microleakage was then scored using a standardized grading system.

Results: Significant differences in microleakage were observed among the groups (χ² = 45.69; p < 0.001). Group 1 (bioactive composite resin) demonstrated the lowest microleakage, with predominantly Grade 0 and Grade 1 scores, while Group 4 (GIC) exhibited the highest microleakage, characterized mainly by Grade 3 scores. Bioactive composite resin exhibited significantly lower microleakage than alkasite, compomer, and GIC (p < 0.05). No significant difference was observed between alkasite and compomer.

Conclusions: Bioactive composite resin (Activa Pronto) provided the most effective seal against microleakage, followed by alkasite and compomer, with glass ionomer cement showing the least effective sealing properties.