What should you know about FDA regulations for additive manufacturing in the dental industry?

Today, digital dentistry uses 3D printing to make surgical guides, dentures, aligners, and other items. Because such devices “go into a body,” the FDA will want a say in whether and how you market these and similar devices. The FDA offers guidance on how to qualify, but here’s a look at some of the information to look for.

Typically, the FDA doesn’t regulate or approve materials used in medical applications. It focuses on devices, grouping them based on risk. However, 3D printing materials are an exception. The FDA does regulate the materials used for 3D printing of dental devices. The agency views materials as finished devices matched to the patient at the point of care. Because these materials are, in a sense, custom in that their purpose is to match to the patient, they become finished devices to the FDA. So, the FDA will regulate the “starting material.”

All medical devices are grouped as Class l, Class ll, or Class lll. A Class l device must demonstrate that it is safe to use and that it is made according to an appropriate quality management system.

A Class ll device must demonstrate that it is equivalent to an existing, already cleared medical device.

A Class lll device has the highest risk when used for treatment and requires greater compliance. Because most dental devices do not fall into Class lll, this category is not addressed here.

Class l devices would include surgical guides, custom trays and so on. The FDA will examine the quality management system (an example is cGMP, current Good Manufacturing Processes), the device’s general biocompatibility, and its mechanical performance data. The manufacturer must register with the FDA and list the devices.

Class ll devices in dentistry include denture bases, temporary crowns and bridges, mouth guards, and aligners. These devices make contact with the body, so approval requires more effort. Manufacturers need to demonstrate that a device is substantially equivalent to an already established device used for the same purpose, that is, obtain 510(k) clearance.

The 501(k) process helps demonstrate the needed equivalence. It helps show that the device treats the same condition in the same way without raising any new concerns about safety and efficacy.

Some Class ll devices are exempt from the 510(k) process. One example is 3D printed denture teeth.

Other devices did not receive a risk category in 1976 when the Medical Device Amendments of the Food, Drug, and Cosmetics Act was enacted. Examples include mouthguards prescribed either to reduce migraine headaches or treat teeth grinding. These devices are “Unclassified” and may require 510(k) clearance for marketing.

A note here, if a device received FDA approval, it has likely received 510(k) clearance. However, clearance for Class or indication does not carry over to other Classes or indications. Each must be sought independently.

For manufacturers or distributors of 3D printing material used to make a dental device, they too face regulation. For example, if a distributor brings a device not cleared in the US, but for sale in the US, then they have the responsibility to register, list, and if the device fits Class II criteria, obtain 510(k) clearance.

The equipment that makes dental devices, i.e., the 3D printers, are not regulated because they are not finished medical devices. The FDA does regulate the software used to design finished medical devices. Usually, software developers work with printer manufacturers to validate the printers, materials, and post-processing ability to produce the finished medical device.

Dental labs should carefully consider 3D printing material when making dental appliances. Use of a non-FDA cleared material could be a risk to patients, which would incur regulatory penalties by the FDA. Note that a material certified for use in Europe (Class IIa) might not be certified in the US, and vice versa.

Dental labs should obtain advice and work with the FDA when working with 3D printing dental materials. Labs may need to register with the FDA.

These are just a few points to bear in mind when developing dental devices using 3D printing. The FDA is the best source for regulatory and compliance information.