Fit Is Not a Manufacturing Religion
An in vitro comparison of five 3D-printed permanent crown resins against milled Vita Enamic found that material choice mattered more than the broad additive-versus-subtractive label, with Saremco Crowntec showing the best internal and marginal fit while Vita Enamic produced the highest external accuracy.
Material choice wins
Source Paper
Comparison of Implant-Supported Permanent Crowns Produced With Different 3D Printed Resins in Terms of Production Accuracy, Marginal Fit and Internal Fit: A Comparative in Vitro Study
Digital dentistry has developed a fondness for tribal identities. Milled. Printed. Hybrid ceramic. Permanent resin. Each arrives with a brochure suggesting it has solved the problem, provided the problem is described in exactly the right font. Fit, unfortunately, is less loyal. It does not care whether the restoration was born subtractively, additively, or during a particularly persuasive lunch-and-learn.
In Comparison of Implant-Supported Permanent Crowns Produced With Different 3D Printed Resins in Terms of Production Accuracy, Marginal Fit and Internal Fit: A Comparative in Vitro Study, Herguner and colleagues tested whether five printable permanent crown resins could match a milled Vita Enamic control for implant-supported crowns. The result is not a coronation. It is a seating chart.
The Data Anchor
The authors fabricated 60 implant-supported permanent crowns across six groups, with 10 specimens per material. Five were additively manufactured resin groups: Bego VarseoSmile TriniQ, Saremco Crowntec, Senertek P-Crown V3, Flexcera Smile Ultra+, and Formlabs Permanent Crown. The subtractive control was Vita Enamic, milled from a hybrid ceramic block.
Accuracy was assessed using RMS deviation against the original digital crown design, following ISO 12836:2015. Marginal and internal fit were measured on sectioned specimens under optical microscopy. The important detail is that the study separated external accuracy, marginal RMS accuracy, internal fit, and marginal adaptation rather than pretending “fit” is one tidy domestic appliance.
Key Findings
- Saremco Crowntec had the best internal and marginal fit. Its internal gap was 55.10 ± 9.433 micrometres and marginal gap was 89.30 ± 20.966 micrometres.
- Vita Enamic had the strongest external accuracy. External RMS was 27.70 ± 6.961 micrometres, outperforming the broader additive group on that surface-accuracy measure.
- Bego VarseoSmile TriniQ struggled in this setup. It showed the worst marginal RMS accuracy at 141.70 ± 39.668 micrometres and the worst external RMS at 92.90 ± 11.239 micrometres.
- The additive-versus-subtractive argument was too blunt. Marginal RMS accuracy was almost identical between subtractive and additive manufacturing, 85.40 versus 85.26 micrometres, while additive specimens showed better internal fit overall.
- Technology labels also blurred the picture. DLP showed lower external accuracy than SLA and subtractive manufacturing, but marginal fit did not differ significantly by technology.
- Limitation: this was an in vitro fit study; it did not test ageing, fatigue, wear, bonding durability, occlusal adjustment, or clinical survival.
💡 The Clinical Bottom Line
For Monday morning, the lesson is not “print everything” or “mill everything.” It is to choose the material according to the clinical priority: internal fit and retention may favour some printable resins, while external surface accuracy may still favour a milled hybrid ceramic in certain contexts.
The broader additive-versus-subtractive debate is too clumsy for the data. The printer is not the verdict, and neither is the mill. The material, the machine, the post-processing protocol, and the measurement target all get a vote. Dentistry, as ever, refuses to be solved by a category label.
Dr Samuel Rosehill is a general dentist with a prosthodontic focus, practising at Ethical Dental in Coffs Harbour, NSW. He holds a BDSc (Hons) from the University of Queensland, an MBA, an MMktg, and an MClinDent in Fixed & Removable Prosthodontics (Distinction) from King’s College London.
Clinical Relevance
This in vitro study suggests clinicians and technicians should not treat additive and subtractive manufacturing as opposing camps with one universal winner. Saremco Crowntec performed best for internal and marginal fit, Vita Enamic performed best for external accuracy, and Bego VarseoSmile TriniQ showed the weakest marginal and external accuracy in this test setup. The findings support material-specific selection rather than method-level loyalty.
Disclosure: The author has no financial conflicts of interest related to the products or topics discussed in this review. This is an independent summary prepared for educational purposes.
Continue the conversation
This review is also published on Substack, where you can leave comments and join the discussion.
Read on Substack →