Taking the bite out of producing dental parts

Laser additive manufacturing (AM), or 3D printing (3DP), is no longer considered just a gimmick, it’s now an accepted method of manufacturing in various industry sectors. In the world of customizable medical components, 3DP has taken off quickly, and with good reason.

It’s well understood that 3D-printed parts allow for innovative design and customization, particularly in components for medical and dental applications. No two people are alike, and our teeth, gums, and mouth shapes are all individual. Dental components, which include braces, bridges, crowns, roots, abutments and removable partial dentures (RPDs), fixation devices, instruments, and tools, can all be individualized to create patient-specific parts.

Currently, 3D-printed dental applications are overtaking traditional processes, such as casting, particularly as consumers become more confident in 3D-printed medical components and appreciate the time savings and customization. Improvements in laser powder bed fusion (or laser metal fusion, LMF) have made 3DP parts faster and more reliable, resulting in production of better-quality parts. Smaller machines, which are designed to be compact and easy to locate in a medical practitioner’s office, bring high precision solutions closer to the end user. An additional benefit is more medical insurance policies cover these new patient solutions, resulting in higher demand for these 3D-printed parts

Many of us can relate to the issues of dental devices with personal experience – whether positive or negative – and can appreciate an expedited, customized process. For replacements of decayed or diseased teeth – traditionally for a root, crown, or bridge – a dental specialist would take X-rays and thoroughly examine the affected area. A latex casting would be created using a mold in the patient’s affected area, then sent away to be manufactured.

Metallic implants in the last 20 years have been typically titanium if fixation into bone is required, as titanium and its alloys are the most biocompatible and reliable of all metals currently used in the biomedical industry. The most widely used traditional process for creating titanium alloy (typically Ti-6Al-4V or Ti-6-4 ELI) is casting. The latex molding of the patient’s affected area is translated to prepare a mold and the part created by casting the metal into the mold. This isn’t a simple process; the whole procedure takes several weeks to create the part and must include time for shipping and handling, and how long it might take to get another appointment with the dental specialist.

In recent years, AM technology has made significant advances in supporting dental applications. The most common applications in the market include production of dental crowns, bridges, and removable partial dentures (RPDs). Dental labs are under increased pressure to improve the lead times associated with these parts and 3DP has enabled them to reduce production times from 3 to 5 days to 24 hours, compared with casting or milling. Through close development with industry leading dental software applications, the overall workflow improvements make the transition to additive production easy for operators. The overall process from design to finished part has been established and proven to provide a perfect fit. Advances in the technology and ability to achieve the required part quality has piqued interest in the industry, but it’s really the lack of skilled casting labor that’s driving the push for AM. The trend of employees with conventional casting skills leaving the workforce and not being replaced is creating a need for change in dental applications.

Moving to LMF simplifies the production process. When using digital scanning to capture the shape and size of the implant required, you don’t inject latex into the patient’s mouth, reducing any risk of allergic reaction. The scan data, used to create the toolpath for the final printed part, can be combined with information to produce more parts to fill a build plate, showing the benefits of the economy of scale by printing multiple parts at once instead of a single part, one by one. Titanium metal, in the form of powder, which is an expensive metal no matter the product form, can then be used more economically with less waste using the LMF process.

The demand for high-quality laser 3D-printed dental components has increased every year, and today, demand is higher than ever. Constraints in the supply chain highlighted during the pandemic and exacerbated during crises, such as the Suez Canal obstruction, war, or other disasters, showed traditional processes can’t be relied on for fast delivery. Instead, to shorten lead time and obtain highly customized, patient-specific parts for treatment, the LMF process offers the solution.

Since the average human mouth doesn’t extend much more than 200mm x 200mm x 200mm, there’s no need for a machine to encompass a giant build nor are multiple lasers required. The right machinery depends on industry end-use, and the medical and dental industries tend to value high quality, repeatability, reliability, and user-friendly systems. Features more important for dental applications might include de-powdering and a build plate removal process that’s quick and easy to perform keeping risk of oxygen exposure of the titanium powder to a minimum. Other features, such as improved gas flow – where shielding gas can drastically influence the presence of defects such as internal porosity or melt-related defects on reactive metals such as titanium – can also be controlled with better processes, resulting in a better-quality printed part.

Laser machine manufacturers are providing better solutions to future-proof the needs of dental and medical practitioners. Improvements in laser AM make it faster and more reliable for 3DP better quality medical and dental components. The industry can employ manufacturing solutions addressing its individual requirements just as it must meet the increasingly customized needs of patients.

About the authors: Eliana Fu, PhD. is industry manager, aerospace & medical and Adam Simons is head of additive manufacturing sales & product at TRUMPF Inc.

TRUMPF https://www.trumpf.com
IMTS 2022 Booth #236217 / #433037