Marginal fit of endocrowns fabricated by three‑dimensional printing and the conventional method:An in vitro study

Abstract

Background: Marginal fit is a key factor in success of prosthetic restorations.This study aimed to assess and compare the marginal fit of endocrowns fabricated by three‑dimensional (3D) printing and the conventional method. Materials and Methods: This in vitro, experimental study evaluated 20 endocrowns, of which 10 were fabricated by 3D printing and 10 were fabricated by the conventional wax‑up technique.The marginal gap was measured at 8 points under a stereomicroscope.The results were analyzed using the Shapiro–Wilk test, paired t‑test, independent t‑test, and one‑way analysis of variance (α = 0.05). Results: The mean marginal gap was maximum at the distal point, and minimum at the buccal point for the conventionally fabricated endocrowns with an overall mean marginal gap of 99.67 ± 4.59 µm. The mean marginal gap was maximum at the mesiobuccal and minimum at the buccal point before pressing (overall mean of 103.92 ± 2.19 µm) before pressing, and maximum at the distobuccal and minimum at the mesiobuccal point after pressing (overall mean of 117.67 ± 2.87 µm).According to paired t‑test,the mean marginal gap of endocrowns fabricated by 3D printing significantly increased after pressing at all 8 points and also in general, compared with before pressing (P < 0.001). Furthermore, the mean marginal gap at all points was significantly greater in endocrowns fabricated by 3D printing compared with those fabricated by the conventional method (independent t‑test, P < 0.001). Conclusion: Within the limitations of this in vitro study, the results showed that endocrowns fabricated by the conventional method had significantly superior marginal fit than those fabricated by 3D printing.