Limits of Digital Technology — When Does Digitalization Stop?

Digitalization in prosthetics represents real progress — faster, more precise, more repeatable. But technology has its physical and economic limitations. A laboratory that understands these limits and can communicate them directly gains more trust than one that sells digitalization as a panacea for every problem. This honesty — "for this case, traditional is better" — signals competence. Not dogma, but pragmatism based on experience.

Scanning Has Its Physical Limits

An intraoral scanner cannot " conjure up" a missing fragment of a tooth wall. If the clinician doesn't scan it, there will be a gap in the digital data — no algorithm can fix that. This is a physical limitation of optics. A margin hidden deep subgingivally (below 3 mm) is practically beyond the reach of a scanner's camera — especially with restricted patient mouth opening or anatomy hindering access. Practical consequences:

Clinical Situation	Recommended Method	Why
Margin above or at gum level	Intraoral scan	Full optical registration without obstructions
Subgingival margin up to 2 mm, good access	Scan after retraction cord placement	Camera sees margin after tissue displacement
Subgingival margin beyond 3 mm	Traditional impression	Silicone physically reaches where the camera cannot
Patient with trismus (limited mouth opening)	Traditional impression or extraoral scanner	Lack of access to the full arch through the limited opening
Crowded or malpositioned teeth	Hybrid – scan + selective impression	Scan where possible, impression where scanning fails

Conclusion: for deep subgingival margins, a traditional impression — though it may seem archaic — yields a more reliable clinical outcome. A gypsum model allows for full analysis without the limitations of a 2D screen.

3D Printing — Resolution, Texture, Margin Precision

3D printing (DLP, SLA, LCD) in a dental laboratory operates with layer thicknesses of approximately 50 µm (0.05 mm). For working models and occlusal splints — this is sufficient. For aesthetic work in the smile zone — the print texture is visible under specific lighting angles. The edge of a printed model will never be as sharp as a CNC-milled model. For delicate crown and bridge margins — milling remains faster and produces more repeatable results in 2026. Practice: Printed works — tooling models, splints, mock-ups, restoration holders. Milled works — everything for the patient's oral cavity (crowns, bridges, veneers, restorations). 3D printing is evolving (25 µm resolution is already available on expensive machines), but not every laboratory possesses this technology. An average laboratory operates at 50 µm resolution — sufficient, but not optimal.

AI Supports, But Does Not Replace the Technician

AI algorithms (in CAD software — automatic crown design, occlusion suggestions, margin rounding) perform excellent in typical cases:

Symmetrical restoration of a single posterior tooth
Occlusion reconstruction with an intact antagonist (the clinician sees how it should be)
Standard cases — a four-unit bridge on abutment-capable teeth

Problems arise with patients presenting with dysgnathia, significant facial asymmetry, severely damaged dentition, or advanced edentulism:

Teeth after extensive loss (patient lost 6+ teeth years ago, tissue has shifted)
Parafunction — patient occludes on one side, asymmetry is completely natural, but the algorithm doesn't know this
Patient's aesthetic preference — patient desires a more rounded shape, AI designs standard anatomy

This is where the CAD technician comes in: additional measurements, analogy with contralateral teeth, spatial analysis on an articulator, discussion with the clinician about objectives. A laboratory investing in technician training will always be more reliable than one relying solely on automation.

Investment and Training as an Entry Barrier

Digital infrastructure requires a significant initial investment:

Laboratory scanner (3Shape, CARES, Medit): 50–150 thousand PLN
CNC milling machine (Roland, Zeno, Medit T-mill): 60–250 thousand PLN
3D printer (Formlabs, SprintRay): 20–80 thousand PLN
CAD software (3Shape, exocad, annual licenses): 10–30 thousand PLN/year
Total: 150–500 thousand PLN (depending on equipment choice and business model)

A small laboratory, working with a volume of less than 80–100 cases per week, would struggle to amortize a full infrastructure within a reasonable timeframe (5–7 years). For them, it is more sensible to outsource milling (sending an STL file to an external CAD printing facility, receiving the finished material, performing their own post-processing), maintaining a digital workflow without machine costs. Traditional prosthetics requires manual skills, technician training (1–3 years), but tools are cheaper and more accessible. A small laboratory can operate effectively traditionally for decades.

Hybrid Approach — The Golden Rule

The best laboratory knows both paths and chooses pragmatically:

For this patient: 100% digital (antagonist scan, CAD, milling, shipping)
For this patient: traditional (impression, manual wax-up, casting, porcelain firing)
For this patient: hybrid (scan, but manual post-processing; or wax-up, but milled material)

The choice results from specific clinical conditions:

Are the margins accessible to the scanner? If not — impression.
Does the clinician want renderings for approval? If yes — CAD.
Can the work be done quickly using a traditional method? If yes — why digitize?

Technological dogmatism ("everything digital, because it's the future") = bad decisions. Pragmatism ("this method for this case") = trust and quality. deltalabs. applies this approach daily — matching the method to the conditions, not vice versa.