Digital laboratories and next-generation dental technicians: past vs present

Dental laboratory technology is the main auxiliary trade for the dental profession and it supports dentistry both materially and technically. It is, by definition, the art and the science of fabricating devices to correct and/or replace natural teeth [1].

Dental laboratories are primarily concerned with the production of five categories of device [2]:

1. partial or full fixed prostheses supported by natural teeth;
2. full and partial removable prostheses;
3. fixed, removable and maxillofacial prostheses supported by implants;
4. orthodontic appliances, devices for sleep apnoea and mouth guards;
5. maxillofacial prostheses such as ocular and craniofacial obturators.

However, dental technicians also provide other important services that facilitate the work of dentists, such as the fabrication of surgical templates for guided surgery, radiographic templates, and simple and complex temporary restorations [3].

All these operations are always based on the written instructions of dentists, who are the designers, as well as the supervisors, of prosthetic projects.

From manual art to industrial mechanics

Until a few years ago, these processes were carried out exclusively by means of direct and indirect sculpting techniques, such as lost-wax casting, model-making by adding or removing material (e.g. wax, ceramic firing, resin pressing, etc.).  

Dental laboratory technology was therefore a predominantly manual art, which involved the use of instruments or equipment pertaining specifically to the field of craftsmanship.

Today, however, the situation has changed radically to favour technologies more akin to those of industrial mechanics. As a matter of fact, the current innovations in the field of dentistry include what we might call “the digital revolution of the dental laboratory” [4].

The introduction of digital systems has revolutionised workflows not only in dental practices, but also in dental laboratories [5,6].

The digital revolution of dental laboratories

Let’s take a closer look at the impact of the digital revolution on the workflows and the main technologies used by dental technicians.

Working times and production processes

In dental laboratories even more than in practices, workflows have been accelerated and processing times have been cut considerably, while simultaneously enhancing the mechanical properties of the materials used and introducing new ones [7,8].

Nevertheless, it is true that these systems still do not make it possible to make restorations with the same aesthetic properties (translucency, grading of different shades within the same structure) on a par with those of restorations fabricated manually by a technician.

Furthermore, in some cases, 3D model printing is a lengthy process, depending on the type of printer and the print parameters set (tilt of the model in relation to the work platform).  

CAD/CAM systems consist of a scanner, software that processes the scan data and makes it possible to design the restorations, and a fabrication system that transforms the digital file into a physical restoration [9].

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Subtractive and additive techniques

The processes used to fabricate digital devices can be either subtractive or additive [10–12].

Subtractive production techniques involve obtaining the restoration, using a milling machine, starting from a block of industrially assembled material in the form of a disk or block [13,14].

Additive techniques, on the other hand, consist of the various 3D printing technologies [15,16]. Today’s digital dental laboratories use the abovementioned production methods for materials such as wax, resins, ceramics and hybrid ceramics [4,9].

Selective Laser Melting and Selective Laser Sintering

For harder materials, such as metals, production is often assigned to industrial milling and printing centres, which have higher performance milling machines and 3D printing technologies such as selective laser melting or selective laser sintering, which currently have costs that are prohibitive for a dental laboratory [17].

In both cases, however, the products of printing and milling are semi-finished devices that must necessarily be finished by a dental technician before they can be handed over to the clinician.

Depending on the material used, after milling a sintering step may be required in order to give the material the appropriate final shape and mechanical characteristics [18].

The post-processing of 3D printing

All 3D printing requires various post-processing procedures, which can also have an adverse effect on the final result unless they are carried out with due care [16].

In addition, certain analogue steps, such as the application of aesthetic finishes (pigments, glaze) or porcelain layering are still essential and therefore must be carried out manually by a dental technician [4].

The impact of new workflows on the dental technician profession

However, all these new workflows are taking their toll on the dental technician profession, where, in recent years, there has been not only a decrease in the number of professionals, but also a deterioration in the skills and knowledge that are fundamental for producing high-quality restorations [19].

As these workflows are a novelty, the lack of training provided to dental technicians regarding these digital techniques and the limited interaction with dentists during training programmes pose a severe threat to the entire patient care team, as future laboratory and clinical standards will be increasingly defined by commercial and industrial interests [2,19].

Furthermore, the new digital dental technicians often lack analogue knowledge, a heritage that is essential for ensuring high-quality work [20].

Are we headed for a deterioration in the creative aspect?

The issue should be dealt with from a deeper and more cultural perspective.

Once upon a time, a craftsman was considered someone who created and produced a product with a specific function with his or her own hands [21]. The prerequisite for his/her creation was the freedom with which he/she interacted with the stimulus for conception and the inspiration he/she received from the outside world to obtain a product that expressed his/her personal interpretation.

A craftsman therefore created, through his/her careful and precise work, unique and unreproducible objects [22]. On the contrary, industrialisation and mass mechanical production starting from a standard design or shape, to be subsequently adapted to the clinical case, eliminate that creative aspect, of attention and experimentation of any possible innovation that starts from scratch.

The question therefore remains whether new production technologies are culturally impoverishing not only the dental technician profession but also all artisanal and manufacturing professions where original, individual and genuine creation was once an added value.

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References

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