Influence of Gutta-Percha Surface on Enterococcus faecalis Initial Adhesion In Vitro: An Atomic Force Microscopy Study

Abstract

The aim of this study was to evaluate the influence of surface topography of gutta-percha (GP) cones and plasticized disks of GP on the initial adhesion of Enterococcus faecalis (E. faecalis). The GP cones (Tanari and Dentsply brands) were cut 3 mm from the apical portion and fixed on a glass slide. To make the disks, the cones were thermoplasticized in standardized molds. The specimens were divided into groups according to the shape of the GP and the presence or absence of the bacteria. For contamination, the strain of E. faecalis (ATCC 29212) was used. The surface topography was analyzed using an atomic force microscope (AFM). The surface, roughness, and waviness parameters were evaluated by the Kruskal–Wallis and Dunn test. The comparison between disks and cones showed significant differences, where the cones were rougher, with a higher value attributed to the Dentsply cone (DC group). The same was observed for the waviness. After contamination, there was greater bacterial accumulation in cones, especially in their valleys, but both the surface and the topography became more homogeneous and smoother, with no differences between disks and cones of both brands. The topographic surface of the GP, at the micro and nanoscale, influences the initial adhesion of E. faecalis, with a greater tendency for contamination in regions associated with the presence of roughness and waviness. In this context, plasticization of GP is indicated, as it reduces surface irregularities compared to cones, contributing to less retention of bacteria.