**7.1. Infiltration base design**

The printing process itself will produce a highly accurate solid model of the missing facial part and consists of printed powder and skin coloured binder. Given the resultant structure post‐ printing processing is required to infiltrate the model with a suitable material with properties that will lend itself to the role required—light, flexible and durable in nature [34]. Due to the post‐printing processing needed for direct prosthesis printing, an infiltration base modelled from the affected and adjacent area must be generated (**Figure 9**). The site of the affected area is imported into the process as a single surface using a suitable CAD software programme. Then using the final prosthesis as a guide, the infiltration base can be trimmed to support the prosthesis and any peripheral extension required in order to define the contact point or provide a feathered edge for final fitting. Each requirement of the prosthesis can be developed within the support with the exact nature of the periphery dependent on the type of facial part to be replaced and the characteristics of the surrounding tissue. Smooth peripheral surfaces will be more suited to feathered edges whilst well‐demarcated wrinkles, or surgical margins will be more suited to a well‐defined edge for closer fitting. Final design features in the infiltration base will depend on the geometry of the missing facial part, but drainage holes and reservoirs may be required in order to provide adequate support and infiltration.

**Figure 9.** Illustrations demonstrating the design and production of an infiltration bed to support the prosthesis during infiltration with a suitable material (Approx. part Dim: 52 × 36 × 25 mm).
