Background and objectives : Individualised therapy of maxillofacial skeleton, especially orbital walls fractures becomes recently more and more popular. Possibility to 3D print a model of a mirrored intact orbit allows to use pre-bent titanium mesh for individual orbital wall reconstruction. The possibility of introducing paper 3D printing technology from Mcor Technologies to create models available for use in operating room was the background of investigation. The technology is promising because of very low cost of model.

Aim : Evaluation of sterilisation process influence to shape stability and cytotoxicity of paper printed 3d models.

Methods : There were printed 30 cuboids 10 mm × 20 mm × 30 mm and 60 cylinders 3 mm height × 14 mm diameter. Cuboids were divided into 3 groups at random. Each group was sterilised using different procedure (radiation, gas plasma, ethylene oxide). Each cuboid was measured using calliper 3 times before and 3 times after sterilization. Cylinders were divided into 6 groups: 3 methods of sterilization, with and without Dermabond cyanoacrylate tissue adhesive coating. Cytotoxicity of 3d-printed paper blocks was tested using normal adult human dermal fibroblasts (ATCC PCS-201-012). Survival of cells was tested using spectrophotometry with XTT and was defined as ratio of absorbancy of tested probe to absorbancy of control probe.

Results : There was no statistically significant influence of sterilization processes to cuboids dimensions. Models showed cytotoxic effect to the cell cultures. Used coating of paper model improved biological behaviour of the material. It decreased cytotoxicity of the model independently of sterilization method. The best method of sterilization for uncoated models was by radiation where gas plasma was the best sterilization method for coated models.

Conclusions : Paper-based 3d printed solids are not allowed to implantation, but it is possible to use them as templates for individual reconstructions of face skeleton even intraoperatively.

Key words : custom paper model; sterilization; shape stability; coating; cytotoxicity