Breast prostheses help restore body appearance and femininity for mastectomy patients, but they can be uncomfortable for some patients. Custom-made prostheses offer better fit and comfort but are typically still manufactured from silicone, which patients report as sometimes heavy.

This study explored the use of soft additive manufacturing (AM) materials with varying geometric infill structures for breast prostheses. Part A of the study evaluated the compressibility of different 3D printed infill patterns, geometry sizes, and thicknesses using different VAT polymerizable flexible materials.

Statistically significant effects were found for infill size (p<0.05) and material-infill shape interaction (p<0.01). Larger unit cell sizes and thinner struts generally resulted in softer structures. FormLabs Silicone 40A was the softest material tested. In Part B, post mastectomy patients rated their perceived softness of a subset of the experimental treatments. The face-centered cubic infill pattern with 7.5 mm unit cell size and 1.5 mm strut thickness was rated the preferred softness, which was marginally stiffer than ratings for a silicone prosthesis. Several designs achieved softness ratings comparable to, or preferred over, silicone prosthesis.

The results demonstrate the potential for using additive manufacturing (AM) to create customized breast prostheses with tailored softness. This research offers a platform for further research to create soft but lighter prostheses for patients targeting improved comfort and satisfaction.