| Theme | Additive Manufacturing, Ecology |
|---|---|
| Project title | Consideration of the recyclability of recycled plastic in the context of additive manufacturing in the field of dental technology for the production of dental models (RecycAligner) |
| Project duration | 01.06.2024 – 31.05.2026 |
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The aim of the RecycAligner research project is to explore whether and how frequently additively manufactured denture models that are used to manufacture aligners can be recycled. Extrusion-based additive manufacturing (fused filament fabrication, FFF) is being investigated.
The questions of degradation, toxicology and surface quality of additively manufactured denture models have not yet been sufficiently answered. The FFF process on a filament or granulate basis enables direct recyclability without chemical treatment.
The investigated process is compared with other model-based processes (SLA process) and model-free processes (direct printing of aligners) in terms of toxicology and clinical suitability. The focus is on material properties and the fit between aligners and reference models, as these affect therapeutic force development. The toxicological investigations evaluate the presence of mutagenic, teratogenic, genotoxic, cytotoxic, and estrogen-active substances in the intermediate and final products of the processes.
A circular economy in the dental field can make the growing market for dental correction more sustainable and reduce waste production through resin-based methods.
The experts in additive manufacturing at IPH are working closely with the orthodontics department at LMU Klinikum München on the RecycAligner research project.
Publications about the project
Sustainable production in dental and orthodontic additive manufacturing is becoming increasingly important due to growing environmental and economic requirements. This study presents a proof of concept for the use of recycled polymers in combination with fused granular fabrication (FGF). Shredded PETG parts are directly processed as granules, eliminating the intermediate filament production step. A desktop 3D printer equipped with a pellet-based extruder was used to manufacture dental models from recycled PETG. Dimensional accuracy was evaluated using optical 3D scanning techniques. The results demonstrate that the produced models are generally suitable for dental and orthodontic applications within the investigated scope. Technical challenges such as unstable material feeding, bridging, jamming and thermal creep were identified and analyzed. The work provides initial evidence that recycled thermoplastics can be incorporated into sustainable additive manufacturing workflows for dental applications and highlights opportunities for future optimization of process stability, print quality and circular material use.
additive manufacturing, 3d printing, recycling, dental models, fused granular fabrication, petg
Can denture models be additively manufactured from recycled plastic? Is the quality still sufficient for medical purposes even after several recycling cycles? The IPH is investigating this together with the LMU Clinical Centre in the ‘RecycAligner’ research project.
3D printing, additive manufacturing, recycling, dental technology
Due to the significantly increasing demand for plastic components, it has become necessary to investigate polymer recycling solutions to eliminate their adverse environmental impact. The focus of this study is to examine the feasibility of recycling polypropylene and a thermoplastic elastomer up to five times using additive manufacturing. This study also focuses on the production and evaluation of the quality of hybrid components based on polypropylene and thermoplastic elastomers. A thermomechanical recycling approach is used, which involves subjecting polymers to thermal and mechanical processes to obtain a usable material form after each recycling cycle. Additive manufacturing was used to produce specimens using the material in both filament and granular form. The thermal, mechanical, and rheological properties of the specimens were characterized by means of various analytical techniques, including tensile test, impact test, optical microscopy, Fourier-transform infrared spectroscopy, thermogravimetric analysis, dynamic scanning calorimetry, and rheological tests in order to study the degradation characteristics of the recycled polymers. The results generally indicate that the chosen recycling procedure causes only slight alterations in the material properties by means of thermal and rheological tests, while impacting mechanical properties and printability.
Additive manufacturing, recycling, polypropylene, thermoplastic elastomers
