An in-vitro Evaluation of Microleakage and Microhardness of Short Fiber Reinforced Composite Versus Composite Resin Inlays in Compound Cavity in Molars

Background: Increasing demand for esthetic, durable posterior restorations has led to the development of various composite techniques. Short fiber reinforced composites (SFRC) claim improved stress absorption, while indirect inlays reduce polymerization shrinkage, potentially influencing microleakage and mechanical properties. Aim: To evaluate and compare the microleakage and hardness of SFRC and composite inlays using direct, indirect, and semidirect techniques in Class II cavities of molars. Materials and Methods: Thirty extracted human molars were randomly divided into three groups (n=10): Group 1—Direct SFRC restorations; Group 2—Indirect CAD/CAM composite inlays; Group 3—Semidirect composite inlays. Standardized Class II cavities were prepared, restored according to each protocol, and subjected to microleakage evaluation using methylene blue dye under a stereomicroscope. Microhardness was measured with a Vickers hardness tester.^4 Data were analyzed statistically with significance set at p < 0.05. Results: Indirect inlays showed no microleakage (Mean = 0) compared with direct (Mean = 0.6) and semidirect (Mean = 1.6) techniques (p < 0.05) (Hasanreĭsoğlu et al., 1996) .Direct SFRC restorations demonstrated significantly higher microhardness (Mean = 58.8) than indirect (Mean = 22.0) and semidirect (Mean = 20.4) inlays (p < 0.05). Conclusion: Indirect CAD/CAM inlays ensure excellent marginal sealing with minimal microleakage, whereas direct SFRC restorations provide superior surface hardness. Clinical choice should balance sealing ability and mechanical durability according to case requirements.