Abstract
Purpose: Laboratory and clinical assessment of cast titanium dentures were reported, little is known
about additive manufacturing (AM) frameworks. This study evaluated in vitro AM titanium alloy clasps
for clinical use.
Methods: After scanning the stainless steel dies to simulate the first molar, an Akers clasp was designed
by CAD. AM clasp specimens were manufactured using laser sintering and AM machines from CP titanium
grade 2 (CPTi), Ti-6Al-4V (Ti64), and Ti-6Al-7Nb (Ti67) powders. As controls, cast titanium clasps were
conventionally made with same three titanium alloys. After nondestructive inspection and surface ele-
ment analysis, surface roughness, fitness accuracy, initial retentive forces, and changes in retentive forces
were measured.
Results: Although few porosities and little contamination of AM clasps were confirmed, the AM clasp arm
and tip indicated slightly worse fitness accuracy as compared to cast clasps. The initial retentive forces of
all titanium clasps showed appropriate retentive forces within the acceptable ranges, AM clasps tended
to have lower decreases in retentive forces with up to 10,0 0 0 insertion/removal cycles as compared to
those of the cast clasps.
Conclusions: AM titanium clasps would be acceptable for clinical use similar to that of cast titanium
clasps.
