Model & Impression Scanners from Dental Wings

December 2016
Volume 7, Issue 12

Digital Service Providers Expanding Options, Benefits

Outourcing options go well beyond simple zirconia milling

By Keith Miolen, CDT

One of the most rapidly growing business transformations in dentistry is the digital outsourcing of technical data both from the dental practice and the laboratory. For the dental laboratory industry that transformation stemmed from the introduction of new restorative materials and the advent of digital technologies to process those materials. What began as an occasional necessity to aid in restoring a patient’s oral situation has today become the status quo for a majority of laboratories and has altered our fabrication processes and workflows forever.

During the first phases of the digital evolution, the cost to invest in CAD/CAM technology was prohibitive for most laboratories. Those who could not afford the initial investment were forced to source out cases requiring the use of milling technology to CAD/CAM-equipped businesses known as milling centers. Most of those outsourced cases involved the milling of zirconia restorations. However, over the ensuing years, the materials and technology as well as the digital processes have expanded to completely change the dental landscape.

Today digital methods of restorative fabrication and communication are applied to virtually every arena of dentistry from the single crown and complex implant cases to removable prosthetics. Access to some end products is restricted solely to an outsource provider. The digitization of dentistry has forced every business owner to consider formulating a production strategy using digital fabrication and workflow methods. Regardless of the strategy adopted, the outsourcing option is in place for any laboratory to utilize. Technology has even led to the creation of new businesses, companies that help provide digital workflows to aid in fabrication processes, controlling costs, and access to new materials. Utilizing these resources also helps laboratories level the playing field regardless of size or revenue.

The following overview will discuss departments within the typical laboratory and elaborate on how a digital workflow can be implemented.

Model Creation

The restorative process starts with the dentist taking an impression, using either an intraoral impression scanner (an increasingly popular method) or traditional impression material and techniques. Digital scans are exported, usually as STL files, from the operatory to a laboratory or via a web portal where a virtual prescription can be filled out with instructions and material selection. The digital prescription can be printed to provide a hard copy to be kept with a case pan for reference.

The clinical scan file may be downloaded and the file opened using the laboratory’s chosen CAD software. Once the case is opened, the digital workflow options emerge.

If a monolithic material has been selected to restore a single posterior case, fabricating a model is optional. However, if a model is required, it can be obtained by exporting the scan to a company with 3D printing technology. Even without an intraoral scan, a digital model may be fabricated using new impression scanning devices and software. This technology presents an opportunity for tremendous growth because it can expand the use of 3D printed models to all aspects of restoring, not just those that started from an intraoral scan. These methods offer creating a fixed cost on model fabrication and require only a scanner and software.

Several companies offer 3D model printing. Stereolithography (SLA) accounts for a growing portion of the market and is most ideal for modeling. An advantage of SLA models is the material’s durability and accuracy throughout the crown fabrication process, much like an epoxy model. Laboratories that receive clinical scans and export the files to an SLA service pay a flat fee based upon each model printed and cured by the provider.

Many providers of SLA technology often offer other services such as substructure and crown design along with fabrication, depending upon the final restorative materials prescribed.

Restorative Design

Fabricating the prescribed fixed restoration or removable prosthetic has traditionally started with hand carving the design in wax. However, in a digital workflow, the wax process is eliminated and replaced with scan and design. Once the model is digitized, the CAD design procedure virtually creates what a technician traditionally would create by hand.

Several outsource providers offer CAD services to create this digital design. Even laboratories that typically handle their own digital design can utilize outsourcing for this step in the event of a backlog of cases. Fees are typically based on the requested turnaround time.

Crowns and Bridges

A majority of outsource centers offer milling or 3D additive services to create end-use crowns and bridges or frameworks in a variety of materials from zirconia and composite to full gold and titanium.

Even for laboratories that mill zirconia in-house, crown-and-bridge outsourcing options can prove useful for those that want to offer a wide variety of materials without the investment required to keep all of them in stock, or for those with mills that are designed to handle only a limited range of materials.

As new materials emerge on the market, the outsourcing option allows laboratories to gauge client feedback with only a limited investment.

Implant Abutments and Bars

Prior to digital outsourcing options, the status quo for laboratories needing a custom abutment was to order a plastic UCLA abutment, and then add and remove contour to a desired shape in order to create a custom abutment design. Once manually designed, the UCLA abutment was then sprued, invested, burned out, and cast. This technique was time-consuming, expensive , and required a significant amount of labor. As the digital services market progressed, providers recognized the inefficiencies with this procedure.

In response, databases were created with a multitude of implant platforms from various manufactures. These platform databases allow today’s laboratory to participate in two primary strategies that are based upon whether a laboratory owns a scanner.

Customers without scanners can ship the model to an outsourcing service provider to scan it before fabricating a custom abutment from titanium or zirconia. Most services allow the customer to evaluate the design prior to fabrication via specific online viewers and links. Once approved by the customer, the abutment is fabricated and delivered along with the model. This service allows laboratory resources to be dedicated to other restorative procedures while the abutment is being fabricated by the service provider—generally, at a lower cost than that of a UCLA abutment. Additionally, many providers offer fabrication services for the substructure and final crown at an additional expense. This additional service is particularly useful for laboratories that do not have milling units or zirconia sintering ovens.

The second strategy allows laboratories that do own scanners and implant software to scan and design their own abutments. The design file is exported to the abutment provider without the need to ship models.

Manufacturers and implant service providers often offer scanners and software packages that yield a quick return on investment based on volume discounts and reduced shipping. Incorporating implant software expedites turnaround time, eliminates the expense of shipping out the working model, and gives the laboratory total control of the design prior to exporting the file.

This fabrication procedure can also be utilized for custom implant bar fabrication for fixed/removable prostheses. The design service technology may also be combined with CT scan and SLA models to fabricate accurate implant guides as an aid in surgical placement of implants.

Removable Prosthetics

Digital production options for removable prosthetics are still in their early stages. The first in-house options for denture fabrication have been introduced only very recently, but outsourcing options have become relatively well established.

Outsourcing partners use different degrees of digital technology to produce removables based on the digital scan data submitted by laboratories. One option is to 3D print a prototype denture and then fabricate the final prosthesis using proprietary methods. Another is to mill the entire denture, including the base, from a puck.

Several new materials and methods for milling and 3D printing permanent denture bases are becoming available.

Additive Fabrication Services

Another popular digital outsourcing option is rapid prototyping (RP) services. This allows laboratories to digitally design a prostheses or substructure using an in-house scanner CAD software and emailing the design data to the provider. The outsource provider either mills, prints, or laser sinters the design. These service providers save laboratories thousands of dollars in initial expenses for costly milling machines, printers, and materials.

Materials used by the service provider are designed to mimic those used for conventional bench fabrication processes. From rapid prototyping materials that can be invested, burned out, and then cast or pressed to final use laser sintered precious metal copings or milled chrome cobalt and titanium frameworks, this service is useful for either fixed or removable treatment plans. RP services are ideal for businesses that have temporarily lost an employee or are looking to reduce labor and material expenses by shortening steps within a procedure.

Partial framework printing is one rapidly growing RP service because it eliminates labor and saves time and materials. Only a scanner is required to take advantage of this workflow aid.

Conclusion

It is evident that digital outsourcing has become a key factor in providing fabrication options to all laboratories. Turnaround times vary depending on the process, but they are generally getting faster as the technologies improve. Many of these options allow smaller laboratories to avoid the major expenses involved with purchasing the CAD/CAM equipment required to produce some of the most popular types of restorations today.

This sector has progressed beyond simply adding certain products to a laboratory’s menu; benefits now include web portals, digital prescriptions, a wide variety of material options, cost savings, and quality. Never before has outsourcing provided such competitive attributes allowing every laboratory to participate and provide options to each client.

Digital outsourcing will continue to grow and be a resource for this industry. Incorporating it as a business strategy provides laboratories with service and product diversity that can aid in the success of all involved.

Keith Miolen, CDT, is the Chief Operating Officer of Aurora Dental Arts in Auburn, New York. He is an NADL Pillar Scholarship recipient and an active IDT Editorial Advisory Board member.

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