A preclinical study comparing single- and double-root 3D-printed Ti-6Al-4V implants.

Recently, double-root implants have been investigated using 3D-printed technology. Here, we investigated damping capacity, microcomputed tomographic (micro-CT) and histological analyses of double-root 3D-printed implants compared with single-root 3D printed implants. Single- and double-root 3D-printed implants were fabricated and placed at both sides of mandibular third and fourth premolars in four beagle dogs. The damping capacity was measured, and periapical X-rays were taken every 2 weeks for 12 weeks. The bone volume/tissue volume (BV/TV) and bone mineral density (BMD) around the implants were measured with micro-CT. Bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) were measured in histological samples. The implant stability values between the groups were not significantly different, except at 4 and 12 weeks. The marginal bone changes were similar at the mesial and distal areas between the groups. The BV/TV and BMD values of the double-root 3D-printed implants showed no statistical difference through micro-CT analysis, but the double-root 3D-printed implants showed lower BIC and BAFO values through histomorphometric analysis compared to the single-root 3D-printed implants. Compared to single-root implants, 3D-printed double-root implants demonstrated comparable stability and bone remodeling around the fixtures, but the statistically significant bone loss in the furcation area remains problematic.