What's the difference between milled and printed digital dentures?

Technology Type:

• Subtractive technology

Technology Type:

• Additive technology

Process Description:

• Starts with solid puck of pre-polymerized PMMA material
• Computer-controlled milling machine removes (subtracts) material
• Cutting burs progressively remove everything that is not the denture
• Reveals a finished prosthesis from within the original block
• Similar to Michelangelo revealing David from a marble block

Process Description:

• Build object layer by layer from liquid photopolymer resin
• Light source (laser or DLP projector) selectively cures resin
• Each layer bonds chemically to the previous layer
• Continues until a complete 3D object is constructed
• Analogous to layered composite placement but at micron scale

Material Properties:

• Uses polymethylmethacrylate (PMMA), same chemistry since 1937
• Pre-polymerized under controlled industrial conditions (temperature, pressure, time)
• Polymerization shrinkage already occurred during puck manufacturing
• Dimensionally stable material (no further shrinkage after milling)
• Achieves true 1:1 fit against a digital master model

Material Properties:

• Photopolymer resins specifically formulated for dental use
• FDA cleared for intraoral use (first cleared 2015)
• Significant material evolution from the first generation (2017) to current high-impact resins
• Chemistry different from PMMA (methacrylate-based polymers with different formulations)

Types of Milled Dentures:

• Monolithic milled (teeth and base from a single two-material puck, e.g., Ivotion milled digital denture)
• Milled base with carded teeth bonded in
• Tooth and base resins chemically bonded during puck manufacturing

Types of Printed Dentures:

• Two-piece printed (teeth and base printed separately, then bonded), e.g. IMPACT digital dentures
• Monolithic printed (new 2024 technology using filament/jetting printers)
• Teeth and base are typically different resins requiring separate print jobs

Advantages:

• Best fit accuracy available with PMMA material (eliminates processing shrinkage)
• Superior mechanical properties (flexural strength, fracture resistance)
• Excellent physical properties (surface hardness, color stability, water sorption)
• Over 10 years of clinical evidence supporting efficacy
• Material is time-tested (nearly a century of PMMA clinical use)

Advantages:

• Lower cost ($400-$600 per arch typically)
• Multiple dentures printed simultaneously (high lab efficiency)
• Printing equipment is affordable ($3,000-$15,000)
• Scalable for high-volume production
• In-house printing economically feasible for practices
• Can print trials, finals, and modifications rapidly

Disadvantages:

• Higher cost ($600-$800 per arch typically)
• Only one denture can be milled at a time (lower lab efficiency)
• Milling equipment can be expensive ($50,000-$150,000+)
• Material waste (removed material cannot be reused)
• Limited to PMMA chemistry (cannot mill other materials easily)

Disadvantages:

• Significant variability between printer/resin combinations
• Surface properties inconsistent across different systems
• Less long-term clinical data than milled dentures
• Bonding required for two-piece systems (potential failure point)
• Material properties still evolving (not yet standardized)

Fit Accuracy:

• Superior (no polymerization shrinkage, true 1:1 fit)

Fit Accuracy:

• Good but variable (depends on printer calibration, resin shrinkage, post-processing)

Strength and Durability:

• Excellent (pre-polymerized material, proven long-term)

Strength and Durability:

• Improving rapidly (high-impact resins approaching milled strength)

Esthetics:

• Good characterization is possible, limited by puck design

Esthetics:

• Excellent characterization (software-designed details print directly)

Stain Resistance:

• Excellent (dense pre-polymerized material)

Stain Resistance:

• Variable (first generation poor, current generation good)

Surface Smoothness:

• Excellent and consistent

Surface Smoothness:

• Highly variable between systems (some excellent, some poor)

When to Choose Milled:

• Patient with high functional demands or bruxism history
• Maximum fit accuracy required
• Preference for time-tested material with extensive evidence
• Single-arch case where lab efficiency is less important
• Willing to pay a premium for the best mechanical properties

When to Choose Printed:

• Cost-sensitive patient or practice
• Multiple dentures needed (efficiency advantage)
• In-house fabrication desired
• Complex characterization is important esthetically
• Trial denture fabrication (printed trials are nearly universal)

Future Trajectory:

• Milled dentures likely remain "gold standard" for demanding cases 

Future Trajectory:

• Printed materials improving rapidly (gap narrowing with milled)
• Monolithic printing (2024) may revolutionize efficiency and esthetics