Researching a new piece of equipment can be time-consuming, but LMT’s done your homework for you. Use this comprehensive article to get educated on welding technology, hear what users have to say and determine which welder is right for your laboratory.
Introduced to the U.S. market in the mid ’90s, welding technology has proven to be a dramatic improvement over conventional soldering techniques, enabling laboratory owners and managers to expand their services, save substantial fabrication time and downtime, reduce remakes and improve the fit and quality of their restorations. As the technology has developed and laboratory owners have discovered more and more applications for welding, it’s been a boon for all departments in the laboratory.
Removable technicians now have the ability to repair partial dentures, add metal occlusals to removable restorations and increase the strength of clasp retention with ease. Crown and bridge departments can weld a simple bridge connection in as little as five minutes, add on to margins and fine-tune the fit of bridge frameworks, or restore the abutments on existing bridgework. Implant technicians no longer have to cast implant appliances because they can laser assemble the titanium components. Thanks to the wide range of indications, welders have become a tool that many laboratory owners/managers say they couldn’t do without.
Amos Harting, who bought a laser two years ago, is one of those owners. “My laser is one of the best tools I’ve ever bought. I don’t have to pre-solder, invest, burnout or worry about the investment model breaking. It’s worth its weight in gold. I wish I bought one years ago,” says Harting of Harting Dental Lab in St. Louis, Missouri.
Since welding can be performed directly on the master model and the process generates very little heat, there is minimal distortion and technicians can weld .5 to .1mm away from acrylic or porcelain with precise control, thus eliminating the need to strip the restoration before repairing it. “Welding saves so many labor hours compared to taking off the acrylic and the teeth and then torch welding. Plus, when you’re doing a repair, you don’t have to worry about the patient saying ‘it doesn’t feel the same,’ which is a typical complaint after the appliance has been stripped,” says Larry Price, CDT, manager, Thayer Dental Laboratory, Inc., Mechanicsburg, Pennsylvania.
Another advantage is that welding is performed in an inert gas (usually argon) atmosphere which displaces the oxygen in the weld zone, preventing oxidation on the joint and creating a more solid, stronger joint. Also contributing to the weld strength is the fact that you’re using wire that is similar to the parent metal and, therefore, the restoration is more apt to be corrosion- and distortion-free. “If you’re using the proper technique and have a good flow of argon over the joint, the weld can be as strong as—or stronger—than the parent metal,” says Price. The use of argon also means materials that are impossible to solder—such as titanium—can be welded.
In addition to the technical benefits, laboratory owner Paul Edwards, Paul Edwards Dental Studio, LLC, appreciates welding technology because it gives him peace of mind. “I bought my laser as an insurance policy for my work. I’m comfortable that I can handle anything with the laser, like cleaning up porosity and pits on a casting, and the weld is absolutely invisible. There are times when I would have remade cases if I didn’t like the fit or the appearance. But with the laser, I can correct those problems and I don’t feel like I’m cutting a corner by not remaking the case,” says Edwards, who has a solo removable lab in Stockton, New Jersey.
What you need to know
There are two types of welding equipment:
Lasers—an acronym for Light Amplification by Stimulated Emission of Radiation—focus a beam of light energy at a particular point to create a melt pool that fuses the material, which can be metal or thermaplastics. Lasers cost in the $20,000 to $30,000 range.
Pulsed arc welders—the more recently introduced technology—work on the principle of electricity; an electrode is connected to the metal appliance and when the tungsten tip touches the appliance, the electrical circuit is completed and creates heat energy that renders the weld. They can only be used to weld metal and typically cost $8,000 to $10,000.
Among users who have experience with both types of welders, the general consensus is that each has its pros and cons. “Both pieces of equipment have their advantages,” says Mark Stueck, C&B manager, Drake Precision Dental Laboratory, Inc., in Charlotte, North Carolina. “For example, lasers offer an unobstructed line of sight but, since pulsed arc welders have a mobile pencil, you can weld large objects off to the side or on a surveyor.”
Thayer’s Price says his preference is dependent on the type of case he’s welding. “I can get a deep, broad weld with the pulsed arc welder whereas the laser is more precise in tight, small areas and gives you greater control over the beam width and pulse,” he says. “We use the pulsed arc welder for partial repairs, implants and titanium, and switch to the laser to repair holes in crowns and for margins and tack welding.”
To determine which type of system is right for your laboratory, you need to assess your needs and do your homework. Here are some tips:
Talk to other users and learn from their experience. Find out what they’re producing, how efficiently they are doing it and compare that with your needs.
Consider your price range. “We have a laser and a pulsed arc welder because we’re full service and work with a variety of different metals,” says Price. “A smaller lab might want to start out with a pulsed arc welder to get its feet wet and then consider a laser if it wants to do more intricate welding.” Also consider that you might be able to expand your marketing opportunities and offer new services—such as titanium laser-assembled implant bars and superstructures, laser partials or outsourcing—to help cover the costs.
Test-drive different systems. “Make sure you do a hands-on test to compare the systems you’re considering and pick the one you feel is the most user friendly,” says Harting, who suggests going to Lab Day Chicago or another trade show, visiting other laboratories or the manufacturer/supplier’s facility, or attending a continuing education program.
Look for a reputable company that can train, install and service the equipment. You want a company that has the technical know-how to fix problems, can provide parts and service quickly if needed and offers thorough system training. “Make sure the company offers hands-on training. Although you could probably learn it on your own, I highly recommend going to a course to thoroughly learn the system,” says Franco Garcia, a supervisor at Becden Dental laboratory in Draper, Utah. He has been using a laser since 1995 for C&B and cast partials.
Get references. Ask the company for a complete customer list and contact those on the list whom you know and trust.
Send samples of all the types of work you want to do to the equipment provider and have the company weld the appliances. This will give you a good idea of the results that can be achieved with its equipment.
Comparison shop using LMT’s comprehensive Shop & Buy section of welders in the January 2006 issue.