Surface microhardness of different thicknesses of a premixed bioceramic material with or without the application of a moist cotton pellet

Abstract

Background: This study was conducted to assess the effect of thickness and hydration condition
on the surface microhardness of Endosequence Root Repair Material putty (ERRM; Brasseler USA,
Savannah, GA), a premixed bioceramic material.
Materials and Methods: Polymethyl methacrylate cylindrical molds with an internal diameter
of 4 mm and three heights of 2, 4, and 6 mm were fabricated. In Group 1 (dry condition), the
molds with heights of 2, 4, and 6 mm (10 molds of each) were fi lled with ERRM. In Groups 2 and
3 (wet condition), a distilled water- or phosphate-buffered saline (PBS)-moistened cotton pellet
was placed directly on the upper surface of ERRM, respectively. The lower surface of ERRM was
in contact with fl oral foams soaked with human blood. After 4 days, Vickers microhardness of the
upper surface of ERRM was tested. The data were analyzed using two-way analysis of variance.
Signifi cance level was set at P < 0.05.
Results: No signifi cant difference was found between the microhardness of three thicknesses of
ERRM (2, 4, and 6 mm) with or without placing a distilled water- or PBS-moistened cotton pellet
over the material (P > 0.05).
Conclusion: Based on the results of this study, it could be concluded that placing a moistened
cotton pellet on ERRM putty up to 6 mm thick might be unnecessary to improve its surface
microhardness and hydration characteristics.

Key Words: Dry, hardness, pellet, phosphate-buffered saline, root repair, silicates, wet
condition