Critical review on methacrylate resin-based root canal sealers.

Introduction: Four generations of methacrylate resin-based sealers have been available commercially. Three of these were introduced during the last 5 years when the concept of simultaneous bonding of root canal sealers to root filling materials and dentin was popularized.

Methods: This article presents an overview of methacrylate resin-based sealers, with the objectives of clarifying the behavior of these materials and delineating their limitations in clinical application.

Bonding of self-adhesive (self-etching) root canal sealers to radicular dentin.

The latest generation of methacrylate resin-based sealers has eliminated the use of separate self-etching primers by incorporating acidic resin monomers in the sealers to render them self-adhesive to dentin. This study examined the adhesive strengths, interfacial ultrastructure, and tracer penetration of a nonetching (EndoREZ; Ultradent, South Jordan, UT) and two self-adhesive methacrylate resin-based sealers (MetaSEAL; Parkell, Farmington, NY, and RealSeal SE; SybronEndo, Orange, CA) when they were applied to radicular dentin following the manufacturers' recommended use of EDTA as the active final rinse. A modified push-out testing design was used to evaluate the dislodgement of core-free sealers.

Contemporary methacrylate resin-based root canal sealers exhibit different degrees of ex vivo cytotoxicity when cured in their self-cured mode.

The cytotoxicity of four methacrylate resin-based sealers was investigated by the 3-(4,5-dimethyl-thiazoyl)-2,5-diphenyl-tetrazolium bromide assay, which measures cell viability by assessing its succinate dehydrogenase activity. The sealers were polymerized in the self-cured mode to simulate the setting condition upon their extrusion into periradicular tissues. Disks were prepared from EndoREZ (Ultradent, South Jordan, UT), RealSeal (SybronEndo, Orange, CA), MetaSEAL (Parkell, Farmington, NY), and RealSeal SE (SybronEndo) together with positive and negative controls.