Effect of Two Different Experimental Mixing Ratios on Selective Physical, Antibacterial and Tissue Compatibility Properties of Two Commonly Used Endodontic Root Canal Sealers—An In-Vitro and In-Vivo Study

Abstract

Many root canal sealers have been launched in the last decade, with a lot of interest renewed in calcium hydroxide [Ca(OH)2], especially its long term intra-canal medication effect. This study aims to introduce two novel experimental composition percentage of calcium hydroxide and epoxy resin based root canal sealers (RCS) material and observe the effect of such formulations in term of working time (WT), setting time (ST), radiopacity, histopathological reactions and antibacterial effects. Four different formulations were formed with first two being experimental while remaining two being pure forms. Each formulation was assigned to a group (Gp) [Gp1 (Base: Epoxy resin 48%, Calcium Hydroxide 39%, Barium sulfate 13%; Catalyst: epoxy resin hardener; Gp2 (Base: Epoxy resin 37%, Calcium Hydroxide 46%, Barium sulfate 17%; Catalyst: epoxy resin hardener; Gp 3 (Pure Resin based RCSs); Gp4 (Calcium hydroxide base cement)]. Physical properties like WT, ST and radiopacity were measured using different tests [WT—Penetration test; ST—surface loss of gloss; radiopacity—fluorescent viewer and bone densometer]. Histopathological reactions were evaluated using 60 healthy rabbits, by injecting subcutaneously (2 sites). Scarified tissue was removed after 3, 14 and 28 days and the inflammatory response was evaluated. Antimicrobial effects were tested by deriving ten microbial samples from randomly selected patients with acute pulpitis followed by culturing. Physical properties were associated with the composition and the percentage of calcium hydroxide. Resin RCS showed the severe inflammatory reaction while the experimental formulation showed mild—moderate inflammatory reaction. One of the experimental formula exhibited the highest antibacterial action against all microorganisms tested.