Digital model fabrication in 3D printing

Intraoral scans, digital data processing, 3D printing - today's dental technology is different than it was ten years ago. But one thing has not changed: A high-precision working model remains the foundation of high-quality restorations. The difference lies not in the technology itself, but in how we use it.

From scan to model: the chain is as strong as each individual link

Modern intraoral scanners provide data in the micrometre range - theoretically optimal. In practice, however, it is the dental preparation that counts: bleeding must be stopped, retraction cords must be placed correctly and preparations must be clean. These basics apply to scanning just as they do to moulding. A standardised scan protocol ensures reproducible results. Current systems are forgiving of minor deviations - but only minor ones. But what comes after the scan?

The right material for printing models: More than just a question of colour

The market now offers a wide range of modelling resins for 3D printing. Colour, feel, odour - they differ significantly. But what should you really look out for? 

• Dimensional stability: A resin with high dimensional stability retains its dimensions - even over long periods of time. This sounds banal, but it is the difference between a usable model and one that "sags" after two weeks. 
• Aesthetics: An opaque material helps enormously for fine detail work in aesthetic restorations. Light brown and grey shades make tooth surface structures perfectly visible.

The optiprintmodel resins from dentona have been developed from and for everyday laboratory use - with colour variants such as Caramel, Cashmere and Dolphin that offer just the right balance between aesthetics and practicality. These are not just better models; they are better working bases.

Model types: The right strategy for every situation

Solid models offer maximum stability, but use significantly more material. Hollow models save resin and reduce wear on the material tray - if the design is right. A wall thickness of at least 3 mm, stabilised by grid structures such as honeycomb or honeycomb structures, prevents cracks when detaching from the building platform. 

Die models with removable dies? That works, but is time-consuming. The alternative: digital design with the didex software enables saw-cut models with integrated pinholes, without reworking. Less effort, better results.

After printing comes the question: How do I reliably match the model of the upper jaw to the lower jaw? This is where it pays to invest in well thought-out systems. Joint constructions directly in the model save time, but require considerable space on the build platform - this reduces the number of models to be printed at the same time. Filling plaster directly onto the model is quick, but does not allow it to be removed from the base. The better concept is a connection geometry directly in the design software, compatible with analogue splitcast systems such as the dentobase system: a metal plate in the model, magnetically fixed - stable, repeatable, adhesive-free connection.

And the highlight: the components can be used multiple times. This significantly increases cost-effectiveness. The didex software offers this geometry already prefabricated - ready for immediate use, without additional design work.Attention: Always wear nitrile gloves when handling liquid resin!

Quality criteria: What is important?

A high-quality printed model fulfils these standards: 

• Surface quality: Smooth structures with a high level of detail (50 µm resolution with anti-aliasing) 
• Accurate fit: implant geometries and model analogues fit reproducibly - without play 
• Dimensional stability: No distortion during removal, contact with isopropanol or during post-curing 
• Dimensional accuracy: the real dimensions are retained after light curing

Digital model fabrication is standard in modern laboratories. But standard and excellence are worlds apart. Quality depends not only on the printer, but also on 

• clean scan preparation, 
• the choice of material, 
• the well thought-out design, 
• Stable solutions for articulation. 
  

Know-how for download