Overview
Additive manufacturing (AM), commonly known as 3D printing, is a digital fabrication process in which objects are built layer by layer from a virtual design file. In dentistry, additive manufacturing has become an essential component of modern CAD/CAM workflows, enabling the efficient production of models, surgical guides, splints, temporary restorations, and even definitive prosthetic components.
Compared to subtractive manufacturing (milling), additive techniques reduce material waste and allow fabrication of highly complex geometries with precision and repeatability.
Core Technologies in Dental 3D Printing
Several additive manufacturing technologies are used in dentistry, each differing in light source, material type, accuracy, and indication.
Stereolithography (SLA)
Stereolithography is a vat photopolymerization process that uses a UV laser to selectively cure liquid resin layer by layer.
Key characteristics:
SLA is widely adopted in dental laboratories and clinics due to its balance of cost and precision.
Digital Light Processing (DLP)
Digital Light Processing uses a digital projector to cure an entire layer of resin simultaneously.
Advantages:
DLP is commonly used for dental models, aligner models, surgical guides, and temporary crowns.
LCD (Masked Stereolithography)
LCD-based systems use an LED light source with an LCD mask to cure resin in layers.
Features:
Material Jetting
Material jetting deposits droplets of photopolymer that are immediately cured by UV light.
Advantages:
Often used for highly detailed models and complex aesthetic applications.
Selective Laser Melting (SLM) / Direct Metal Laser Sintering (DMLS)
Selective laser melting and related metal powder bed fusion technologies use a laser to fuse metal powders layer by layer.
Applications in dentistry:
These technologies are primarily used in dental laboratories and industrial production environments.
Materials Used in Dental Additive Manufacturing
Material selection depends on clinical indication, mechanical requirements, and regulatory approval.
Photopolymer Resins
Used in SLA, DLP, and LCD systems.
Types include:
These materials offer high accuracy and good surface finish but may have lower long-term mechanical strength compared to milled ceramics.
Metal Powders
Common alloys include:
Metal additive manufacturing enables strong, lightweight frameworks with complex geometries that are difficult to achieve through casting.
Ceramic-Filled & Hybrid Materials
Some printable resins contain ceramic fillers to improve:
Research continues into fully printable ceramic restorations; however, milled zirconia remains the dominant material for definitive high-strength restorations.
Applications in Dentistry
Additive manufacturing supports both clinical and laboratory workflows:
Integration with intraoral scanning and CAD software enables a fully digital workflow from scan to printed output.
Advantages of Additive Manufacturing
Limitations
For definitive ceramic restorations requiring maximum strength, subtractive milling of zirconia may still be preferred.
Clinical Relevance
Additive manufacturing expands the capabilities of digital dentistry by providing flexible, cost-effective production of models and appliances. When combined with CAD/CAM milling systems, 3D printing enables optimized workflows, faster turnaround times, and highly customized patient-specific solutions.
The continued development of printable biomaterials and improved printer accuracy is expected to further integrate additive manufacturing into routine restorative and prosthetic dentistry.