AccScience Publishing / IJB / Online First / DOI: 10.36922/ijb.2918

Novel patient-specific gingival soft-tissue expander development for large bone defects using silicone 3D-printing technology

Tzu-Huan Huang1,2 Shao-Fu Huang3 Lu-Yi Yu3 Chun-Liang Lo3 Yu-Ping Chang1 Chun-Li Lin3*
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1 Department of Biomedical Engineering, National Yang Ming Chiao Tung University, Taipei, Taiwan
2 Department of Oral and Maxillofacial Surgery, MacKay Memorial Hospital, Taipei, Taiwan
3 Department of Biomedical Engineering, Medical Device Innovation and Translation Center, National Yang Ming Chiao Tung University, Taipei, Taiwan
Submitted: 12 February 2024 | Accepted: 4 April 2024 | Published: 10 May 2024
© 2024 by the Author(s). This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution 4.0 International License ( )

The current hydrogel self-inflating expander is limited by its volume and linear expansion rate, making it unsuitable for correcting patient-specific large mandibular bone defects in soft-tissue surgeries. This study devised a novel approach for crafting patient-specific gingival tissue expanders for large mandibular bone defects by employing silicone 3D-printing technology. The biocompatible and swellable polymer tablet was compressed and placed into a 3D-printed silicone membrane to evaluate its expansion capability. Two patient-specific large left and right mandibular bone defects with complex geometries were selected to generate defect expander models in a computer-aided design (CAD) software. The swellable tablets were enveloped in the 3D-printed silicone membranes to form soft-tissue expanders, which were then immersed in phosphate-buffered saline (PBS) for 6 weeks to observe their expansion. Results demonstrated that a slot-shaped silicone soft-tissue tablet attained an expansion volume of 1960 mm³. A fourth-degree polynomial fitting curve illustrated slower expansion rates in the initial 2 weeks and achieved complete expansion in about 6 weeks. Patient-specific silicone expander testing indicated less than 2% error in the average expanded volumes of compared to CAD models. The cross-sectional profile of the soft-tissue expanders closely resembled the CAD model. This study demonstrated that biocompatible polymer could be utilized as swellable tablet material and enveloped within a 3D-printed silicone membrane to generate a novel soft-tissue expander that adhered to clinical standards. Additionally, the study validated the feasibility of expanding patient-specific silicone expanders within 6 weeks for repairing large left and right mandibular bone defects.

Silicone 3D printing
Soft-tissue expander
Bone defect
This study was supported in part by the Ministry of Science and Technology (MOST; Project numbers: 108-2622-E-010- 001-CC2 and 110-2222-E-032-003-MY2), Taiwan.
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Conflict of interest
The authors declare no conflicts of interest.
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International Journal of Bioprinting, Electronic ISSN: 2424-8002 Print ISSN: 2424-7723, Published by AccScience Publishing