In the era of digital dentistry, 3D file formats are the foundation of workflows involving intraoral scanning, CAD/CAM design, dental milling, and 3D printing. Among the most widely used formats are STL, PLY, and OBJ—each with unique properties that affect data quality, file size, and compatibility with dental software and hardware.
Understanding the differences between these formats is essential for dental professionals, technicians, and software developers working with digital impressions and restorative design.
• Most common format in digital dentistry.
• Represents 3D surfaces using a mesh of triangular facets.
• Originally developed for 3D printing, now standard for CAD/CAM workflows.
• Universally accepted by nearly all dental CAD/CAM systems.
• Compact file size and fast to process.
• Excellent for restorative design, milling, and 3D printing.
• No color or texture information
• No metadata (e.g., tooth numbers, scan type, or alignment data)
• No point cloud data – only mesh surface
• Crowns, bridges, inlays/onlays, surgical guides
• Milling and 3D printing
• Export from intraoral scanners (e.g., CEREC, 3Shape TRIOS, iTero)
• Contains both geometry and color/texture data
• Supports point cloud and mesh formats
• Increasingly used in aesthetic dentistry and orthodontics
• Includes RGB color information
• Better suited for soft tissue visualization, gingiva, and tooth shade mapping
• Useful for AI and diagnostic applications
• Larger file sizes
• Not universally supported by all dental software
• Slower to process than STL
• Aesthetic analysis (e.g., smile design)
• Soft tissue contour scanning
• Patient monitoring and communication
• A 3D geometry format that supports color (via MTL files) and textures (via image files)
• Widely used in graphics and animation, but gaining traction in dentistry
• Detailed surface data with texture mapping
• Compatible with virtual smile design and patient-facing visuals
• Can be used with augmented and virtual reality platforms
• Requires multiple associated files (.obj, .mtl, texture images)
• Larger and more complex to manage
• Limited support in some dental CAD software
• Digital smile design and treatment planning
• Orthodontic simulations and aligner visualizations
• Patient education and marketing visuals
Feature | STL | PLY | OBJ |
|---|---|---|---|
| Geometry Support | Mesh only | Mesh + point cloud | Mesh only |
| Color Support | No | Yes (embedded RGB) | Yes (via textures) |
| Metadata Support | No | Limited | With MTL file |
| File Size | Small | Medium to large | Medium to large |
| Software Support | Very high | Moderate to high | Moderate |
| Best Use Case | CAM, 3D printing | Aesthetic and diagnostic scans | Visualization and design |
• Intraoral Scanners: Most support export in STL, with newer models also offering PLY and OBJ.
• CAD Software (e.g., exocad, 3Shape, Dental Wings): Typically supports STL; PLY/OBJ may require plug-ins.
• CAM/Milling Software: Optimized for STL files due to their clean surface geometry.
• 3D Printing: STL remains the standard, but PLY and OBJ are emerging for multi-material and color printing.
Workflow Stage | Recommended Format |
|---|---|
| Intraoral Scanning | STL, PLY |
| Restorative Design | STL |
| Aesthetic Planning | PLY, OBJ |
| Orthodontics/Aligners | STL, PLY |
| Patient Visualization | OBJ, PLY |
| 3D Printing | STL |
• Multi-format interoperability: Software and hardware becoming more flexible with PLY/OBJ.
• Color 3D printing: Driving demand for richer file formats with texture data.
• Cloud-based workflows: Managing larger, detailed formats (PLY/OBJ) more efficiently.
• AI-powered diagnostics: Require detailed anatomical and color data (best handled by PLY).
Understanding the strengths and limitations of STL, PLY, and OBJ file formats is essential in modern digital dentistry. While STL remains the industry standard for most restorative workflows, PLY and OBJ offer valuable advantages in aesthetic and diagnostic applications where color and texture are important. Choosing the right format for the right task ensures accuracy, efficiency, and patient satisfaction in every step of the digital dental workflow.