At Dental Lab we use the highest quality machines and materials. We use only safe and proven technologies, for which we hold certificates. Despite the introduction of innovative solutions, we maintain safety and introduce only tested products, preceded by appropriate testing and preparation.

3D PRINTERS

We have DMLS/SLM* printers for metal and SLA printers for light-curing resins. Large machine park and competent staff allows us to apply modern technologies with the use of various technologies. Recently, we have introduced semi-finished products made in hybrid DMLS/CNC technology, combining the advantages of sintering and milling. This allows us to obtain precise implant components with high precision and at low cost.

EOS M100 metal 3D printer – DMLS/SLM* technology

The EOS M100 printer provides industrial DMLS/SLM technology in a compact form factor for laboratories and R&D departments. It is the smallest 3D printing system for metal, which is an excellent solution for the production of individual products and small production batches of small parts. The system uses a proven fibre laser (200W), which ensures process stability and the construction of high-quality parts.

High process parameters enable fast and economical production. In addition, the small diameter laser spot and high resolution allow the construction of geometrically complex shapes. The combination of a fibre ytterbium laser and a new generation of laser exposure parameters and a print parameter stabilisation system ensures the highest quality of production. The density of manufactured elements (100%) and their accuracy, fixed by annealing in a special furnace, guarantee certified workmanship and full satisfaction of clients.

Dental 3D printing in SLM/DMLS/LaserCusing technology – laser sintering/metal sintering and SLA – 3D models/light-curing resin technology*

*DMLS (Direct Metal Laser Sintering) is a registered trademark of the German company EOS (Electro Optical Systems). SLM (Selective Laser Melting) is a registered trademark of MCP Hek, which is currently used by SLM Solutions, MTT and Renishaw, Realizer. Laser Cusing, on the other hand, is a proprietary technology name owned by Concept Laser, a company within the Hofmann Innovation Group. EOS and MCP Hek used the SLM name in parallel at the start of the technology’s development. However, MCP was the first to claim it, which meant that EOS had to create its own name – DMLS. All of these names refer to the technology of selective sintering and melting of powdered metals with the help of a laser, applied in layers until a finished fully durable part is obtained.

Rapid Prototyping – 3D printing; Selective Laser Melting [SLM/DMLS/LaserCusing] – laser sintering

SLA (Stereolithography) technology consists in deflecting a laser beam through a system of mirrors, which scans the surface of liquid resin in the place where it is to be cured (to create a model). Commonly referred to as stereolithography – light-curing resin technology.


3D PRINTING/MILLING DMLS/CNC

Having a diverse and modern machine park, we can combine various technologies and thus obtain products of the highest quality obtained in an innovative manner. Apart from crowns and bridges, or skeletons, obtained by laser sintering of DMLS metals, we can also boast of the implementation of production of precise elements of dental prosthetics (approx. 5 microns) using DMLS sinter, which is then milled in appropriate places on a super-precise CNC milling machine. This is an innovative hybrid DMLS/CNC manufacturing technology.

Technologia hybrydowego druku DMLS / CNC

The hybrid technology for the production of precision semi-finished dental prosthetics is a combination of the traditional CNC milling method and the DMLS selective sintering method. The method has been tested in the DentalLab laboratory in Gdansk, Poland, since 2017 and was implemented into production in September 2018.

This technology has far fewer limitations compared to the traditional method of CNC milling of dental prosthetic components used for implantology. Only the CNC milled points have to be designed according to art and prepared as for milling (working angles, tool lengths, positioning of work in the grid structure after implant insertion etc. are important) and the remaining surfaces are spatially constructed without the limitations of the additive DMLS method.

The machines, materials and software used in the lab are:

– 3D printer DMLS EOS M100

– iMES iCore 750i milling machine

– NABETHERM protective gas annealing furnace

– metal powder EOS CobaltChrome SP2 (REF:9011-0018) – a medical product according to Class IIa of MDD Directive 93/42/EEC, Annex IX, Rule 8 [cobalt-based metal-ceramic alloy, used for the manufacture of dental prosthetic components – free from Ni, Be and Cd according to ISO22674]

– CAD software – 3Shape, ZirkonZahn, EXOCAD

– CAM software – MATERIALISE’s MAGICS file repair and digitalisation software, 3Shape’s CAMbridge and others

– 3D laboratory scanners: 3Shape, MEDIT, ZirkonZahn;

The DMLS manufacturing technology used is certified by EOS.

The DentaLLab laboratory, as the only one in Poland and one of several in Europe, is on the international list of authorized EOS-Dental-Service Providers

The hybrid manufacturing method consists of three stages:

1. development of a prepared CAD design in CAM software integrated for SLS (Selective Laser Sintering) and CNC milling (e.g. Make& mill)

2. the manufacture of work using DMLS technology

3. finishing of work pieces using CNC milling technology.

The use of hybrid DMLS / CNC technology allows for the production of high-quality implantology work with all the advantages of additive technology (3D DMLS printing), which include: high productivity, low loss of material, constant work quality over time, quality of the machined surface, improving adhesion of covering materials, which are applied in further production processes (veneering or cementing) and, above all, low manufacturing costs, as well as CNC cavity machining, which has the special feature of high precision.

Examples of applications:

DMLS PRINTING TECHNOLOGY

**DMLS technology, or Direct Metal Laser Sintering, is a 3D printing technology for metal parts that has been developed by EOS for over 20 years. The initial idea of prototyping metal parts using the DMLS method, has evolved into a mature manufacturing technology, offering exceptional design freedom to designers from various industries.

Repeatable strength parameters of created elements and the number of industrial and medical production implementations are the elements that distinguish the DMLS method from similar solutions of the SLM or LaserCusing type. The idea of this technology is to build complex shapes, impossible to create with casting methods from materials difficult to process.

Advantages of the DMLS/SLM/Laser Cusing technology in dental prosthetics applications

– acceleration of production processes

– increase of accuracy and quality of the performed works

– construction of dental crowns and bridges from biocompatible certified alloys

– possibility to create non-standard elements

– high density of the manufactured element (100%)

– reduction of material stress by appropriate production technology, guaranteed by printer manufacturer EOS

Operation of DMLS/SLM/Laser Cusing machines

Machines operating in the DMLS/SLM/Laser Cusing technology apply successive layers of precisely composed metal powder on the working platform.

Then, on each layer this powder is selectively melted into an element of the constructed object using a very precise laser beam and appropriate power. Such a printout takes place in a protective atmosphere of inert gas, such as argon or nitrogen.

A key aspect of the 3D printing process is the need for very precise control of the laser beam and continuous purification of shielding gas from impurities generated during melting. These contaminants are often porous and can contain residual amounts of metal oxides and trapped gas bubbles. If the contaminant falls onto the remelted surface and is then covered by another layer of powder, it can be fused into the material structure, causing precipitates with a different density to the alloy material. The quality of production is therefore determined by the experience of the printer manufacturer, the quality of the metal powder and the accuracy and cleanliness of the handling.

In the general principle of operation, DMLS, SLM (Selective Laser Melting) or LC (Laser Cusing) technologies are similar to each other. The above-mentioned variety of technology names results from the registration of the names as trademarks. Due to existing patent restrictions, manufacturers of SLM and LC (LaserCusing) machines pay patent fees to EOS (as the original creator of this method), while using several proprietary solutions that distinguish one technology option from another. An example would be the rubber bands that spread the powder in the machines in exchange for the steel or ceramic blades used in DMLS technology.

What distinguishes EOS DMLS machines

EOS is a company that sets the course for the development of laser melting of metal powders and plastics in terms of the quality offered and the number of installed systems, industrial deployments and organisational structure. Through many years of cooperation of the EOS brand with its key customers from many industries, the DMLS technology is the most frequently implemented solution for production of metal parts by means of 3D printing.

With the EOS M280 and M290 machines, components for items such as aircraft engines from GE and UTC are produced. In addition, further aerospace companies such as MTU and RolsRoyce are preparing for new implementations involving DMLS technology. On EOS machines, dental components have already been produced for many years in place of the existing milling and casting. The machines also build implants designed for individual patients.

3D Dental Printing in SLM/DMLS/LaserCusing – laser sintering/metal sintering and SLA – models/light-curing resin technology*]

*DMLS (Direct Metal Laser Sintering) is a registered name of the German company EOS (Electro Optical Systems). SLM (Selective Laser Melting) is a registered trademark of MCP Hek, which is currently used by SLM Solutions, MTT and Renishaw, Realizer. Laser Cusing, on the other hand, is a proprietary technology name owned by Concept Laser, a company within the Hofmann Innovation Group. EOS and MCP Hek used the SLM name in parallel at the start of the technology’s development. However, MCP was the first to claim it, which meant that EOS had to create its own name – DMLS. All of these names refer to the technology of selective sintering and melting of powdered metals with the help of a laser, applied in layers until a finished fully durable part is obtained.

Rapid Prototyping – 3D printing; Selective Laser Melting [SLM/DMLS/LaserCusing] – laser sintering

SLA (Stereolithography) technology consists in deflecting a laser beam through a system of mirrors, which scans the surface of liquid resin in the place where it is to be cured (to create a model). Commonly referred to as stereolithography – light-curing resin technology.

GUIDELINES FOR CAD/CAM COOPERATION – 3D SCANNING/PRINTING/MILLING IN DENTAL TECHNOLOGIES

EOS, IMES, ZirkonZahn, MEDIT, EXOCAD, 3Shape, DentalWings – 3D Dental printing in SLM/DMLS/LaserCusing – laser sintering/metal sintering and SLA – models/light-curing resin technology*]

The laboratory has implemented an electronic handling system that allows secure communication in a closed system protected by security features equivalent to those of banking systems. Collaborations can therefore take place rapidly, securely and, in addition, allow collaborators to use their user panels to utilise CRM,ERP business functions for their own purposes, such as event archiving, file and model archiving, notifications, billing, reporting, dispatching, claims and more.

You no longer need to fill out forms, just go to the laboratory website or your panel and send files to production. The rest will be done by the B2B dental24 IT system which saves everything and automatically sends notifications about your correspondence to the relevant people. All of this takes place in dental24 SaaS system, which is protected by highest level of security, certificates and encryption keys exceeding level of security of some banking systems.

In case of any doubts or questions, we provide immediate contact with the CAD/CAM department via telephone lines and electronic communication channels, including Skype. An experienced team is available to provide competent information at any time.

Preparation of files for DSLM/SLM printing

The following are guidelines proposed by EOS and suggestions from our technicians, marked with an asterisk (*), for the correct preparation of files intended for DSLM/SLM 3D printing and sinter processing:

Some CAD software is designed for milling processes. The designed files may have holes in the mesh, consist of several meshes and are leaky, so they cannot be used in the DMLS/SLM printing process.

Work intended for 3D printing must have a single mesh. Closed and tight.

A single .STL file cannot consist of several separate objects.

A dense triangulation of the mesh provides the best surface. If triangulation is too sparse, the object surface may not be detailed enough.

The fit of the corona depends on the triangulation of the inner surface of the corona. For the best model surface quality you should:

-use scanning spray on reflective surfaces

-Set the scanning quality to high.

* Based on the experience of our technicians, in order to reduce the amount of errors in the grid, we suggest to check the parameter settings of angles and spaces at the crown neck (shown below). The crown neck is a detailed element and has a complex mesh in which there may be many intersecting surfaces.

Bridges and crowns – wall thickness

The recommended wall thickness in the design is 0.5mm. The minimum wall thickness should be 0.4mm. If the value is lower, there is a risk of damaging the element in the printing process and during further manual processing.

Bridges and crowns – space for cement

The values for cement space and additional space are suggested values. Usually, the amount of this space depends on the shape of the crown and the dentist’s preference.

Bridges and crowns – constrictions

The constrictions should not be too high. If the value is too low, there is a risk that the walls will have surfaces that are too thin for a stable printing process. The values given are recommendations by EOS and also depend on the software used.

Bridges and crowns – preparation limits

The values indicated are suggested by EOS. The preparation limit depends on the CAD software and the preferences of the dental technician.

Bridges and crowns – connecting points in a bridge span

The thickness of the abutments depends on the shape, the number of points and the surface area.

EOS recommends a minimum thickness of 6mm² of cross-sectional area for the bays in the area of anterior teeth and 9mm² for the area of premolars and molars.

BRIDGES AND CROWNS – CERAMIC THICKNESS

Substructure design

Ceramics should be between 0.8 and 2.0mm thick. If the ceramic is thicker than 2mm cracks may form due to internal stresses in the material.

The design of the substructure must be appropriately matched to the shape of the ceramic in order to avoid ceramic thicknesses in excess of 2mm.

The shape, thickness and position of the bridge span joints must also be chosen accordingly.

The point must be adequately supported from the base by the substructure.

SURFACE PREPARATION – PORCELAIN FIRING

* Cutting off the supports

Sintered prosthetic devices must be supported by longitudinal structures (supports) during laser melting in order to

– support the component during production

– prevent deformation of the remelted metal

– dissipate heat

Each work piece in its raw state is cut off from the platform together with the support structures, which must be removed in order to subject the product to further processing steps. Supporting structures should be removed using profile pliers or pliers. To remove the support structures, grasp them with the pliers and twist gently to break them off.

Supports have different exposure parameters than prosthetic components and are therefore more susceptible to unscrewing/breaking out. Do not break the support by grasping it, as this may cause plastic deformation or damage to the work. In case of difficulty, it is advisable to grip and unscrew the supports one by one.

Surface preparation

The surface of the prosthetic device can be finished with a drill, diamond or carbide cutter. After finishing, the surface should be sandblasted with Korox (AlO) at 3-4 bar and cleaned with a steam jet (steamer).

Firing of ceramics

Opaquer should be applied in two phases. A first, thin layer (Washbrand) and a second layer of opaquer. Wash under running water before applying the next layer of ceramic. EOS recommends a long cooling phase (up to approx. 600°C). Ceramics should only be removed mechanically. Hydrofluoric acid causes corrosion of the metal.

Ceramics

Ceramics according to ISO 9693 with a firing temperature of up to 980°C should be used. Ceramics with reduced firing temperatures are also suitable.

List of ceramics recommended by EOS

** Information from www.bibusmenos.pl was used.

COMMUNICATION SYSTEMS

The company allows cooperation in all the most common CAD/CAM technologies.

It has its own communication/cooperation system and is also connected to closed systems dedicated to selected products.

Thanks to its state-of-the-art and versatile equipment, it is able to carry out even the most complex orders in the shortest possible time and with the highest quality, supported by the relevant certificates.

3Shape Communicate™

Communication system between users of 3Shape products