Dental laboratories are today experiencing a digital revolution. Until recently, hand-cast, machined and refined dentures have been the mainstays of dental technology for dentists. Increasingly, however, laser-melted implants, abutments, crowns and bridges are being used in the dentistry field. The Fresdental manufacturing centre in Spain is one example of the digital industrialisation of dental technology that is changing the face of dentistry.
Fresdental works with dental laboratories as a manufacturing centre for the industrial production of implants, bridges and crowns. It was founded in 1999 near Alicante, and as a specialist service provider for dental laboratories the company is able to manufacture custom-tailored dentures very quickly. The cornerstone of Fresdental’s business is implants, which account for approximately 70% of its sales.
Fresdental’s customers include over 240 dental laboratories across the Iberian Peninsula and South America. The company uses conventional denture production methods such as 3-axis DSC milling machines and, since 2005, CAD/CAM techniques such as laser melting of metals. Fresdental also supports dental laboratories in the production of 3D models for intraoral scanners.
Combining efficiency and quality
Of the 11 manufacturing machines in the 840m2 production space at Fresdental, two use metal Additive Manufacturing (AM) technology.
“Our two Mlab cusing laser melting systems from Concept Laser are an example of the increased use of advanced CAD/CAM methods in dental technology,” explained Denture Engineer Francisco Perez Carrio, also noting that CAD/CAM technology in dentistry arrived early in Spain.
For Carrio, the advantages are clear – the more affordable price, the ability to produce multiple dentures in a single building job on a single building board, and the high rate of speed to arrive at the final product are key benefits.
The technology also earns points, however, for its low energy consumption, material reuse, absence of tool requirements and reduced staff costs. “We can actually produce more dental products with fewer people,” stated Perez Carrio.
“Compared to traditional, manual-production-based dental laboratories, digital manufacturing is extremely cost-efficient and offer enormous advantages in terms of quality. The cost of producing an average denture is around €20. With LaserCUSING, it drops to slightly less than €10. Basically, we’re talking at least half the price. As an industrial manufacturing centre, we see ourselves as a service provider of choice as well as an extension of the dental laboratory. Laser melting of metals is a logical expression of digitization in production, which allows us to achieve the highest quality standards.”
High accuracy and complex design
Fresdental specialised early on in highly complex geometries, and it’s in this area, with its wide-span designs or orthodontically embedded implants, where the free-form process scores major points. “In terms of fit, geometric freedom or delicate constructions, the technology provides new opportunities for dental technicians and dentists,” explained Perez Carrio. “Basically, it allows us to create designs that better benefit the patient. The additively constructed designs are superior to conventionally produced dentures in both performance and durability.
The additive structure allows safe ceramic veneering, such as through innovative ceramics. Surface faults that occur with casting, such as bubbles, are non-existent with laser melting. With rapid manufacturing methods like laser melting, the lab can select the most functional and affordable dental prosthetic solution based on the customer’s needs, be it crowns and bridges, frameworks, abutments, primary and secondary structures or implant supra-constructions.”
Industrial manufacturing with full process parameter control
The type of material selected, according to Perez Carrio, depends on the application. The trend is toward flexibly insertable, transparent and tooth-coloured materials. The LaserCUSING process makes it possible to economically produce caps, bridge structures, abutments, cast parts, as well as primary and secondary structures from powder. In addition to mechanical equipment, the alloy powder used is essential for a high-quality prosthetic framework as the composition, powder form, grain size and grain size distribution determine the quality and precision of the parts produced.
“For us, it’s important to be able to influence all the process parameters during the construction process,” stated Perez Carrio. “This lets us define and customise not only the geometry, but also the density, stiffness and elasticity or modulus of the final product as desired.”
Another factor is the combination of module or multi-component construction. Base elements implanted into the jawbone are used as primary structures. An additively manufactured foundation element is then put into place as a secondary structure, onto which a secure, durable veneer such as HeraCeram is applied. Manufacturing companies such as Fresdental have many years of experience as pioneers in production technologies and are considered digital experts in the orthodontics industry.
This advanced technology not only allows bridges with more than ten sections, for instance, to be manufactured tension-free in a one-step process, it also allows their increased use in high-impact areas, as cantilevers, around edges or with brace elastics. With model casting, this is not always an easy problem to solve. Tension in the construction is reduced through heat treatment. This includes tension that occurs when the rough product is fired in the ceramic oven for cosmetic coating purposes. “There are many different methods for reducing tension, even if we still need training in some of them,” added Perez Carrio.
The digital process chain
A continuous digital process chain is the next step in the laser melting for dental technology. Intraoral scanners are, therefore, high on the priority list for Fresdental. The reason is simple – Intraoral scanners, used by dentists to generate primary digital data, can be used for digital generation of STL design data. “The continuous digital process chain from the patient to the dental product will accelerate data migration both in terms of quality and speed. Intraoral scanners will soon become standard in dentists’ offices. Laser melting of metals is a logical expression of digitization in production. Laser melting is the future – there’s no escaping it,” stated Perez Carrio.
LaserCUSING® technology from Concept Laser
The LaserCUSING® process from Concept Laser is used to create mechanically and thermally stable metallic components with high precision. Depending on the application, it can be used with stainless and tool steels, aluminium and titanium alloys, nickel-based superalloys, cobalt-chromium alloys or precious metals such as gold or silver alloys.
In the process, fine metal powder is fused using a high-energy fibre laser. After cooling, the material solidifies. Component contour is achieved by directing the laser beam with a mirror deflection unit, or scanner. Construction takes place layer by layer, with each layer measuring 15-150 microns, by lowering the bottom surface of the construction space, then applying and fusing more powder.
Concept Laser states that its systems stand out due to their stochastic control of the slice segments, also referred to as “islands”, which are processed successively. The company states that the patented process significantly reduces tension during the manufacture of very large components.