Instructions for Use (IFU) for biocompatible resins

These Instructions for Use (IFU) define the general processing conditions and responsibilities associated with the use of biocompatible photopolymer resin systems supplied by 3Dresyns®.

Important: 3Dresyns resin systems are supplied as professional manufacturing materials for additive manufacturing workflows. They are not placed on the market as finished medical devices, certified medical components, or CE-marked accessories. Any medical device manufactured using these materials remains under the sole regulatory responsibility of its legal manufacturer.

Biocompatibility and performance of printed parts depend on strict adherence to qualified workflows. Deviation from these instructions may significantly affect material behavior, safety and biocompatibility outcomes.

The manufacturing of medical and dental devices using 3D printed materials requires appropriate expertise, validated equipment, controlled workflows and robust quality assurance. Printing alone is not sufficient: biocompatibility is achieved only through correct printing, post-processing and controlled polymer conversion. 3D resins are raw photoreactive materials. Only after validated printing, post-curing and cleansing can printed parts potentially meet biocompatibility requirements for a specific intended use.

This document is part of the broader system-level documentation architecture defined by 3Dresyns®. See Medical & Biocompatible 3D Printing Framework for a structured overview of IFU hierarchy, residual species control and workflow-dependent biocompatibility.

Residual species, extractables and leachables

Photopolymer conversion is not absolute. A fraction of unreacted species, additives, photo accelerant fragments, light blockers and reaction by-products may remain within the printed structure depending on formulation, printing parameters and post-processing conditions.

These residual species may be released under relevant use conditions, including exposure to saliva, biological fluids, blood, solvents or temperature variations. The release of such extractables and leachables may influence the biological response of the final device.

The control of extractables and leachables is therefore a critical aspect of biocompatible additive manufacturing and must be considered at the system level.

• formulation design and selection of raw materials
• degree of polymer conversion achieved during printing and post-curing
• effectiveness of washing, drying and cleansing protocols
• geometry, thickness and internal accessibility of printed parts
• validation of extractable and leachable profiles under intended use conditions

Depending on the application, advanced purification, cleansing or extraction methodologies may be required as part of the validated manufacturing workflow to reduce residual species to acceptable levels.

Monomer Free (MF) resin systems are designed to reduce the presence of reactive residual species at the formulation level, thereby minimizing potential extractable-related risks when processed under validated conditions.

Scope of application

This IFU applies to biocompatible photopolymer resin systems used in medical, dental, laboratory and research manufacturing workflows.

These instructions describe general processing principles and do not replace application-specific validation, risk assessment, regulatory evaluation or device-level instructions defined by the legal manufacturer.

Material system and version control

3Dresyns biocompatible resins are supplied as system-based manufacturing materials that may exist in multiple formulation versions.

• Users must ensure that the selected material version, lot number and associated documentation correspond to the intended workflow and reference testing data.
• Mixing versions, modifying formulations or using expired materials may invalidate expected performance and biocompatibility outcomes.

Printer compatibility, setup and required equipment

Biocompatible resins must be used with compatible additive manufacturing technologies and validated printer configurations defined by the selected material system. Printer calibration, optical integrity and environmental conditions must be verified prior to production. Printer-specific parameters significantly influence polymer conversion, residual species and final part performance.

Required equipment

• Constant-power printers and light boxes with minimal light power decay over time. Variable or low-power systems may lead to insufficient polymer conversion and increased residual reactive species.
• Printers and post-curing units with uncontrolled or variable light output may result in low degree of polymerization and inconsistent performance.
• Thermal oven capable of operating between 60–100 °C where thermal post-curing is required.
• Quality control instrumentation to verify dimensional accuracy, mechanical properties and process consistency.

Printing parameters and build conditions

Printing parameters such as layer thickness, exposure strategy, orientation and support design must follow validated reference configurations.

• Follow Instructions for Use & Printing Parameters and the technology-specific IFU relevant to your printer (SLA, DLP, LCD, 2PP, Inkjet, etc.).
• Printing parameters directly affect polymer conversion, extractables and final safety.
• Changes to printing parameters may alter mechanical behavior, surface chemistry, residual species and biological response and therefore require re-validation by the user.

Post-processing requirements

Post-processing is a critical component of biocompatible manufacturing workflows. Printed parts must undergo validated washing, drying and post-curing steps as defined by the selected material system.

Insufficient or excessive post-processing may result in residual extractables, altered surface chemistry, incomplete conversion or reduced material stability. Only validated post-processing equipment and qualified conditions should be used.

Clear vs. colored prints in biocompatible workflows

Clear, transparent and colored prints may require different post-processing strategies. Transparency alone does not guarantee polymer conversion. Conversion depends on printer output, part geometry, post-curing dose and the complete cleansing and drying workflow.

Colored and opaque prints: light penetration limitations

Opaque and colored resins limit light penetration during post-curing. Standard light-box curing may be insufficient because light may not penetrate through the entire thickness of the part. This can leave residual unreacted species in internal zones, especially in thick sections, complex geometries and strongly tinted or opaque prints.

Residual unreacted species may increase extractables and leachables and negatively impact safety and intended biocompatibility performance. For such cases, validated thermal post-curing protocols may be required to support maximum achievable polymer conversion throughout the part.

Thermal post-curing guideline (70–100 °C)

• Thermal post-curing is typically performed in the range of 70–100 °C, depending on resin formulation and intended application.
• Users must determine and validate the lowest temperature and time achieving required performance and safety outcomes.
• Thermal post-curing must be combined with adequate cleaning and drying prior to curing.

Important: Post-curing in a light box alone may be insufficient for colored or opaque prints due to limited light penetration.

Handling, storage and contamination control

• Printed parts intended for regulated applications must be handled under appropriate contamination control measures.
• Resins and printed parts must be stored according to defined temperature, light exposure and humidity conditions.
• Cross-contamination with non-qualified materials must be avoided.

Relationship to testing and validation

Biocompatibility-related testing data (where available) are generated under defined reference configurations including material version, printer type, post-processing equipment and processing parameters.

• Deviation from reference configurations may invalidate the relevance of testing results.
• Changes in geometry, exposure strategy, cleaning chemistry, post-curing, finishing operations, packaging or sterilization may alter extractables and leachables profiles.
• The legal manufacturer must determine whether additional testing is required for the intended application.

Regulatory responsibility

3D resins are raw manufacturing materials and are not certified medical devices. The responsibility for safety, conformity assessment, biological evaluation and CE marking lies entirely with the legal manufacturer of the final device.

In the EU, 3D printed medical devices fall under Regulation (EU) 2017/745 (MDR). The legal manufacturer must perform conformity assessment, maintain technical documentation, issue an EU Declaration of Conformity and apply CE marking before placing a device on the market.

Responsibilities of the user

• Users are responsible for selecting appropriate materials, equipment and validated workflows.
• Application-specific validation and regulatory compliance remain the responsibility of the legal manufacturer.
• 3Dresyns does not assume responsibility for misuse, off-label applications or deviation from qualified workflows.

Related technical framework

• Extractables and leachables in photopolymer 3D printing
• IFU for Biocompatible Resins
• Medical & Biocompatible 3D Printing Framework
• Polymer conversion in photopolymer 3D printing
• Biocompatible Photopolymer Engineering Knowledge Base
• Technical documentation

Governing principle

Safe use of biocompatible photopolymer resins requires strict adherence to validated processing, cleaning and post-curing workflows. Deviations may alter residual species profiles and biological response.