Analysis of the marginal and internal fit of hybrid ceramic and polyetheretherketone endocrowns manufactured with CAD/CAM: An In Vitro approach

Abstract

The restoration of severely damaged endodontic teeth is a challenge, since the main rehabilitation consists of posts that can generate fracture and tooth loss. As an alternative to this problem the endo crowns have been employed. This method requires less invasive preparation, but marginal and internal adaptation is important for its longevity. Objective: To analyze the marginal and internal adjustment of hybrid ceramic and polyetheretherketone endocrowns made in CAD-CAM. Methodology: In vitro experimental study in which an artificial mandibular first molar was prepared with (n=20) hybrid ceramic (n=10) and PEEK (n=10) CAD/CAM endocrowns. The marginal adjustment was evaluated using a Canon EOS-Rebel-T3i camera with a 100mm macro lens and MR-14EX-II-Macro-Ring-Lite ring-flash on four surfaces (vestibular, lingual, mesial and distal) while, the internal adjustment was evaluated at four different points (Point-A: mesio-axial-occlusal, Point-B: mesio-axial-pulpal, Point-C: disto-axial-pulpal, Point-D: disto-axial-occlusal). Statistical analysis was performed in the Stata-14 program and the results obtained were analyzed with the parametric T-Student test and the nonparametric Mann-Whitney U test. Results: The PEEK end-crowns obtained an average marginal adjustment of 89.09±5.92μm while, the hybrid ceramic end-crowns obtained an adjustment of 98.87±4.14μm. In terms of internal adjustment, the average PEEK adjustment was 183.63±4.50μm and the average hybrid ceramic adjustment was 195.47±2.41μm. Although these variations show statistical differences, clinically there are no significant differences. Conclusions: The CAD/CAM produced endocrowns presented better marginal and internal adjustment which is observed in the PEEK material.