As a reader of these blogs, you’ll probably know that in the world of measurement we care a great deal about terms like accuracy and precision. So, you’ll have to forgive the following, unvalidated (and thus somewhat out-of-character) claim. It’s this: no one likes visiting the dentist. Seriously. There’s enough anecdotal evidence to suggest that it’s a fact that we’re happy to run with the assertion without actually measuring it for accuracy.
However, it’s also true that visiting the dentist could be an even worse experience than it is already. For the fact that it’s not, in large part we have machine tools to thank. In this blog, we’ll look at why this is the case by examining the variety of crucial roles that this equipment plays in dental manufacturing.
Bridges over troubled water?
Most of you will have experienced one of the following procedures: a bridge, a prosthetic, or a crown. Maybe even an implant. And likely, you’ll have taken it for granted that whatever the dentist is installing in your mouth will “work”. But any such component must meet, by its nature, precise and intricate requirements so it’ll fit perfectly into the available space. That means that materials – metals, ceramics, and polymers depending on the application – must be precisely cut and shaped. This is generally achieved using Computer Numerical Control (CNC) milling machines.
And what about cylindrical components, like teeth themselves (or, more precisely, dental implants and custom abutments)? Rather than milling, here lathes are required for turning and shaping as well as grinding machines to achieve fine surface finishes and precise dimensioning necessary.
It’s not just what goes in your mouth that requires accuracy and precision in manufacturing either. The dentist’s tools and instruments themselves must meet the same high bar. For the dreaded drills as well as burrs, and other weapons(!) in the dentist’s arsenal, lathes and grinders are commonly used in manufacturing. For more intricately shaped instruments where material is removed from a workpiece, Electrical Discharge Machining (EDM) is often deployed.
The production of intricate shapes – regardless of whether the raw material is metal or ceramic – tend to rely on laser cutting machines while plastic components such as dental trays mainly rely on injection molding. Then, there’s the more familiar automated polishing machines which use abrasive materials to polish and buff surfaces.
The bottom line (and the point here) is that a combination of different machine tools allows the dental supply industry to produce high-precision, custom, and mass-produced dental equipment and prosthetics with efficiency and accuracy.
Use case: Let’s build a bridge!
Forgive the pun! Now we understand something of the range of dentistry applications and the machine tools responsible for them, let’s Look more closely at the example of dental bridges to enable us to understand the centrality of machine tools’ role. Manufacturing this component involves several steps which combine the expertise of both the dentist and the manufacturer’s laboratory. Here’s how the process works:
First, the dentist examines the patient and, in this case, particularly the area of the missing tooth and health of the adjacent teeth. Presuming the latter are strong, some enamel is removed from them to make room for the incoming bridge. Impressions (molds) are then made to create a precise model of the patient’s mouth.
Here, for our purposes, it gets interesting. The impressions are sent to the laboratory where technicians create a custom bridge possibly involving various materials including porcelain, ceramic, metal, or a combination of such. Milling machines are central to the creation process, enabling the end product to fit precisely, consistent with the required bite. This (milling) involves a rotating multi-toothed cutting tool used to remove material from the prosthetic tooth’s surface. The machine can make the necessarily complex shape in various raw materials so it’s particularly relevant to dentistry applications.
Returned to the dentist for fitting, further adjustments to the bridge may then be made before it’s cemented or bonded into place. How important is milling? It’s perhaps particularly notable that a growing number of dental offices now have in-house milling machines partly to enhance final accuracy and also to reduce overall treatment time.
Machine tools and dentistry
As you can both see and probably imagine (it’s your mouth after all), accuracy is critical to assuring the performance of both the dental component and the dentistry tool used to create it. There isn’t any margin for error in either case though achieving the desired outcome is challenging. So, the machine tools responsible for producing our desired outcomes (in the bridge case, the milling machine) must perform optimally.
One, if not the crucial factor in achieving this level of performance should be the deployment of a measurement system. Let’s look at just one practical example of such a solution: a camera-based machine tool measurement system. Made for measuring in machine tool settings, effective deployment of such a system will improve manufacturing outcomes. And while any measurement system can make a difference, camera-based systems are particularly effective in milling machine scenarios.
Let’s look at their impact. Measurements are most commonly taken “outside of the machine”, for example using vernier calipers, v-anvils, or micrometers. The presumption is that you can just read the specs from any of the above and know what accuracy you get relying on your measurement equipment.
But that’s not true. The micrometer has, for example, a written spec of 0.00005″ accuracy or if you buy a good quality one with a ratchet (to minimize user errors) it can have an impressive precision of 1.3 µm. Yet, no machinists are surprised when they see variations four times higher when measuring tools rather than end products. Why? Essentially because measurements take place in real world conditions, where there’s an ongoing environmental impact at play on the tool’s performance.
Now, you could measure “inside the machine” using different measurement approaches but similar problems exist because the in-machine environment itself is no less troubling. This is where a camera-based tool measurement system comes into play. Made for measuring tools regardless of the environment, camera-based technology eliminates real world issues that affect manufacturing (heat, dirt, dust, fingerprints – all the enemies of accurate manufacturing) if you can create a reference measurement of the milling cutter.
To summarize, there should be no shortcuts to accuracy where your mouth and health are concerned, and a lot of parameters to consider if you want to achieve the best possible outcomes. When it comes to dental health, behind the crown, measurement devices are king! If you’d like to discuss the subject with us directly, please click the link below.
About Conoptica
Conoptica has been providing high tech camera-based measurement solutions for the metal working industry since the 1993. We make sure that the metal working industry has access to key quantitative data about their products and tools. Conoptica is the market leader for measurement equipment in the wire & cable industry.