CAD/CAM: Digital Design and Prosthetics

Computer-aided design and computer-aided manufacturing — CAD/CAM for short, known in French by the acronym CFAO — refers to a set of tools that make it possible to design a dental restoration on a computer and then produce it by milling or printing. In practical terms, it replaces some of the manual steps of impression-taking and fabrication with a digital workflow. It is a technology, not a treatment in itself: it is used to produce crowns, veneers, inlays/onlays, and bridges, but it is the clinical indication and the practitioner’s work that determine the result — not the machine.

As a dental surgeon in Kenitra, I offer here a factual, measured description of CAD/CAM: what it is, how the workflow runs from the scan to the restoration, which materials are used, what the literature says about the fit and survival of digital restorations, and where its limits lie. Our practice uses a digital CAD/CAM workflow. Every statement is backed by a verifiable source, and no figure is presented as an individual guarantee: these are study data, to be read as probabilities.

# What is CAD/CAM in dentistry?

CAD/CAM is the application to dental prosthetics of two families of tools: computer-aided design (designing the restoration on a screen) and computer-aided manufacturing (the automated production of the piece). It does not create the tooth: it helps design and mill a restoration that must still be fitted, adjusted, and bonded or cemented by the practitioner.

A review published in Bioinformation (Maiti and colleagues, 2024) describes the process in three stages: “the first step is to capture the dental anatomy with an optical scan to create a digital impression; the second uses CAD software, where the practitioner designs the restoration on a computer; the last implements CAM, where the design is sent to a milling machine or a 3D printer.” These three links — scanning, design, manufacturing — form the digital chain.

There are two main manufacturing routes. Subtractive milling starts from a block of material (ceramic, for example) from which a milling unit carves out the restoration. 3D printing, an additive process, builds the piece layer by layer. The two coexist and do not serve the same purposes: milling remains the reference for ceramic crowns and veneers, while printing is developing mainly for models, guides, and provisional restorations.

# The digital workflow: from scan to restoration

The CAD/CAM workflow replaces the putty impression with a digital acquisition, then moves on to design and manufacturing. Schematically, it involves the following steps:

• The digital impression. An intraoral scanner records the shape of the prepared tooth, the neighboring teeth, and the occlusion, and produces a 3D model. This step, its indications, and its limits are detailed in our article on digital impressions with an intraoral scanner.
• Design (CAD). On this model, the practitioner or the dental technician designs the restoration: shape, contact points, occlusion, margin lines. The software proposes a morphology, which is then adjusted to the case.
• Manufacturing (CAM). The design is transferred to a milling machine or a printer. The piece is milled from a block, then finished (staining, glazing, crystallization firing for certain ceramics).
• Try-in and placement. The restoration is tried in the mouth, its fit and occlusion are checked and adjusted, and it is then bonded or cemented.

This workflow can be fully digital (direct chairside scan) or hybrid (conventional impression, then scanning of the model at the laboratory). The distinction matters for fit, as we will see below.

# Materials used in CAD/CAM restorations

CAD/CAM does not define a material but a way of manufacturing; several families of blocks are available, each with its own trade-off between esthetics and strength.

• Lithium disilicate is a reinforced glass-ceramic, esthetic and strong enough for many single anterior and premolar crowns. The review by Maiti and colleagues (Bioinformation, 2024) credits it with a flexural strength above 350 MPa.
• Zirconia (zirconium oxide) is considerably stronger — the same source cites a flexural strength of 500 to 1200 MPa — which makes it suitable for high-load areas and for patients who clench or grind their teeth.
• Hybrid ceramics and millable composites offer good machinability and intermediate behavior.

The material is chosen according to the tooth’s position, chewing forces, and esthetic expectations, exactly as for a conventional restoration. This topic is covered in more depth in our articles on ceramic and zirconia crowns and ceramic dental veneers. CAD/CAM is the shaping tool; the material and the indication remain the true clinical variables.

# What the literature says about fit

The argument most often made in favor of digital workflows is the precision of the fit — that is, the marginal and internal adaptation of the restoration. The data broadly point in that direction, but with nuances.

A systematic review by Arcuri and colleagues (Journal of Biological Regulators and Homeostatic Agents, 2019), covering all-ceramic restorations evaluated in vivo, concluded that “CAD/CAM restorations obtained with an intraoral scanner show better marginal and internal fit than those obtained from a conventional impression digitized at the laboratory.” In other words, the direct digital workflow is a valid — even favorable — alternative to the indirect workflow where fit is concerned.

A more recent umbrella review (Singh and colleagues, Cureus, 2025) confirms that intraoral scanners offer clinically acceptable accuracy for single-unit and short-span restorations. It adds a clear caveat, however: their accuracy decreases in complex cases, particularly full arches and edentulous situations, where “conventional or hybrid workflows may remain preferable.” The superiority of digital is therefore not universal: it depends on the span and the clinical context.

# What the literature says about survival

A good fit does not guarantee longevity. On this point, CAD/CAM restorations benefit from substantial follow-up, especially for single-unit pieces.

For chairside restorations, the review by Fasbinder (Journal of the American Dental Association, 2006) reported a survival probability for restorations produced with the CEREC system “of approximately 97% at five years and 90% at ten years,” with ceramic fracture as the main mode of failure. Over the very long term, a case series by Otto (International Journal of Computerized Dentistry, 2017) followed CEREC 1 inlays and onlays and observed survival of approximately 87.5% at up to 27 years based on Kaplan-Meier analysis — a result the author describes as “highly acceptable” for restorations placed in private practice.

For lithium disilicate specifically, the review by Pieger, Salman, and Bidra (Journal of Prosthetic Dentistry, 2014) reported cumulative survival of single crowns of approximately 100% at two years and 97.8% at five years. For all-ceramic CAD/CAM bridges, the systematic review and meta-analysis by Saravi and colleagues (Materials, 2021) reported five-year survival in the range of 89.7% to 91.1%, with secondary caries as the leading cause of failure and chipping of the veneering ceramic as the most frequent complication.

These figures are survival rates drawn from studies, not a promise for any given restoration. Longevity depends as much on the supporting tooth, the occlusion, oral hygiene, and the patient’s habits as on the manufacturing technology.

# The single-visit restoration: possible, but not routine

One of the advantages highlighted for chairside CAD/CAM is the ability to design and mill certain restorations within the same visit, with no putty impression and no temporary restoration while waiting for the laboratory. This is real, and the survival data above partly concern this workflow.

But it is neither automatic nor suited to every case. Single-visit feasibility depends on the type of restoration (a single posterior crown is not a complex bridge), on the chosen material — some ceramics require firing or staining that lengthens the timeline — and on esthetic demands, since the anterior region often calls for finer prosthetic work. Presenting the single-visit restoration as a standard that applies everywhere would be an overpromise. It is a useful option in selected cases, not a general rule.

# The limits of CAD/CAM

Honest information means naming this technology’s limits.

First, digital workflows do not eliminate clinical constraints: a preparation margin that is hard to see, bleeding gums, or excessive moisture degrade a scan just as they degrade a conventional impression. The quality of the result depends first and foremost on the preparation and on control of the working environment.

Second, superiority is not systematic. The umbrella review by Singh and colleagues (Cureus, 2025) highlights the limits of scanners on full arches and edentulous cases. And the systematic review and meta-analysis by Aswal and colleagues (Cureus, 2023), comparing CAD/CAM crowns and bridges (lithium disilicate and zirconia) with conventional restorations, concluded that biological, technical, and esthetic outcomes were “broadly similar,” while observing “more biological, technical, and esthetic complications in the CAD/CAM group than in the conventional group” in their analysis. The authors consider that CAD/CAM techniques “still need to evolve” to surpass conventional techniques. This nuance matters: CAD/CAM is a capable, convenient tool, not a guarantee of clinical superiority over well-executed conventional work.

Finally, a restoration, even one designed digitally to perfection, remains subject to aging, wear, and the same complications as any restoration: caries at the margin, fracture, debonding. Regular follow-up and good oral hygiene remain essential.

# In summary

CAD/CAM is a digital chain — scanning, design, manufacturing — that makes it possible to design and mill ceramic dental restorations, from lithium disilicate to zirconia. The literature indicates marginal fit that is at least comparable, and often better, with the direct digital workflow for single-unit restorations (Arcuri et al., 2019), favorable medium- and long-term survival (around 97% at 5 years for chairside restorations according to Fasbinder, 2006), and, in selected cases, the possibility of a single-visit restoration. But this is not universal superiority: scanners have their limits on full arches, complications do occur (Aswal et al., 2023), and no lifespan is ever guaranteed. CAD/CAM is a tool in the service of the indication and of follow-up, not a substitute for either.