Influence of Different Adhesive Systems on Marginal Integrity in Deep Margin Elevated Restorations: An In-Vitro Analysis

Abstract

Achieving durable marginal integrity remains a crucial factor for the longevity and success of restorations involving deep margin elevation (DME). The choice of adhesive system plays a significant role in ensuring an optimal bond between the restorative material and tooth substrate, especially when margins are placed below the cemento-enamel junction. This in-vitro study aimed to evaluate the influence of different adhesive systems—etch-and-rinse, self-etch, and universal adhesives—on the marginal integrity of deep margin elevated restorations. Standardized Class II cavities with subgingival margins were prepared on extracted human molars and restored using resin composites following DME procedures. Marginal adaptation was assessed through dye penetration and scanning electron microscopy (SEM) after thermocycling to simulate clinical aging. Results indicated that universal adhesives demonstrated superior marginal sealing and reduced microleakage compared to self-etch and etch-and-rinse systems, likely due to their versatile bonding mechanism and improved chemical interaction with dentin. The findings suggest that adhesive selection significantly impacts the interfacial stability of DME restorations and should be guided by both substrate condition and restorative protocol.