Feasibility of Shore 00 Hardness Measurement of Porcine Oral Soft Tissues and a 3D-Printed Tissue-Simulating Material: A Pilot Study

Background/Objectives: Simple methods for quantifying the local mechanical properties of oral soft tissues are needed to select materials for physical oral models. This pilot study evaluated the feasibility of Shore 00 durometry on porcine oral mucosa and illustrated its use for screening a 3D-printed elastomer. Methods: Shore 00 hardness was measured on single specimens from five sites (gingiva, three palatal sites, and buccal mucosa) of one animal. Specimens of Formlabs Elastic 50A V2 were printed by masked stereolithography in two orientations, post-cured for 7–27 min, and tested on the Shore 00 and Shore A scales. Results: Mean tissue readings ranged from 32.0 ± 3.3 Shore 00 (buccal mucosa) to 48.2 ± 5.5 Shore 00 (gingiva), with within-site coefficients of variation of 3–12% and a decline of successive readings at two sites. The printed elastomer gave readings of 86–87 Shore 00, 38–55 units above all tissue sites. Shore A hardness increased linearly with post-curing time (approximately 0.2 Shore A/min), whereas the Shore 00 readings did not change. Each orientation was printed in a separate build; the estimated difference between the two builds was less than one unit on each Shore scale; the effect of orientation could not be isolated. Conclusions: Shore 00 durometry yielded readings within the working range of the scale for porcine oral mucosa and clearly separated the tissue from the printed elastomer. A standardized protocol and biological replication are required before the method can provide reference values.