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.
Key Words: Dental marginal adaptation, dental prosthesis, printing, three‑dimensional