Find out what's hot in furnace technology

April 4, 2012

With the many furnaces available from numerous manufacturers, selecting just the right one can be a daunting task for any dental lab technician. There also are four categories of furnaces to differentiate from, each made to best handle varying tasks. Having more than 30 years of component-level electronics experience, Daniel Serrago of IBEX Dental Technologies Inc., Richardson, Texas, literally knows all types of furnaces inside and out.

With the many furnaces available from numerous manufacturers, selecting just the right one can be a daunting task for any dental lab technician. There also are four categories of furnaces to differentiate from, each made to best handle varying tasks.

Having more than 30 years of component-level electronics experience, Daniel Serrago of IBEX Dental Technologies Inc., Richardson, Texas, literally knows all types of furnaces inside and out.

He’s agreed to share some of that furnace know-how with DLP. Serrago offered information about the differences between furnaces, features, specifications, latest developments in furnace technology and a check list to use before making a purchase.

After serving as a Master Radio Electronics officer as a U.S. Merchant Mariner back in 1979, Serrago maintained and repaired ships’ computer navigation, engine room automation controls and radio/satellite communications equipment.

That experience led him to establish Garland Dental Services about 16 years ago and later IBEX. Over the years, he has taken apart, fixed and put back together just about every kind of dental furnace that exists.

“As the owner of Garland Dental Services, I have repaired hundreds of furnaces of all makes and models over the past 16 years,” he said.

Furnaces are expensive and important pieces of equipment for lab technicians. Here’s Serrago’s breakdown of the types of furnaces available and the tasks they handle:

Firing Furnace - Used to vitrify porcelain, the firing furnace is still the backbone of the dental lab industry when it comes to furnaces. Firing furnaces require excellent temperature and heat rate control. They frequently fire in a vacuum environment, so maintaining vacuum also is important.

Burnout Oven - Used to “burn out” casting and pressing rings, the burn out oven is a staple in the dental lab. Because of the rings’ ability to be burned out over a broader temperature range, less stringent temperature controls are required, and the oven doesn’t use vacuum.

Pressing Furnace - Used for pressing today’s pressable porcelains and ceramics. Pressing furnaces have all the same control requirements as the porcelain furnaces with the addition of the pressing hardware and controls. Almost all of today’s pressing furnaces allow you to program porcelain firing programs as well.

Sintering Furnaces - Used to sinter yttrafied zirconia (yz), sintering furnaces are a unique class of furnace. They are required to operate at much higher temperatures than conventional firing or pressing furnaces. To achieve these temperatures, special ceramic heating elements and power control electronics are employed.

It’s all about performance

How any given furnace performs is what sets one furnace apart from another, Serrago said.

“All porcelain and pressing furnaces manufactured today are microprocessor controlled providing a variety of program capacities and features designed to make its operation easier, in theory,” he said. “While there are other differences worth noting, I believe that what truly sets one furnace model apart from another is its performance consistency, its ability to provide the technician with predictable results firing after firing. This critical factor is not determined by how many programs it can store or by where the Night Mode button is located.”

The design of the electronics and muffle is what produces predictable firing qualities, he said. And the combined performance of today’s furnace electronics and muffle designs varies greatly between manufacturers.

Bells and whistles

What features and specifications are most important is an individual choice for every technician.

“Unlike stereo systems or HDTVs, the important technical specifications defining the electronics and muffles used in today’s furnaces are simply never published,” Serrago said. “Features abound in today’s furnaces. It all comes down to personal preference. Do you truly need 200 programs or is it critical that you can place your favorite photos on the full color displays now available on some furnaces?”

Let how well the furnace consistently and predictably fires be the most important feature, he said. Then look at ease of use.

“How easy it is to program and to manipulate, edit, move, copy or change parameters on the fly?” Serrago said. “Equally important is the furnace’s dependability and the level and cost of maintenance and support from the manufacturer, especially after the warranty period expires. Some repair parts assemblies can cost upwards of 20% of the cost of a new furnace.”

Unlike buying clothes

When buying clothes or finding the latest fusion restaurant to dine at, there’s usually a new trend to consider. That isn’t the case with furnaces. Trends in furnaces have remained stable for quite some time. There really aren’t a lot of, excuse the expression, “hot” new features to boast about when it comes to furnaces.

In general, since the mid 1990s, firing and pressing furnace performance has changed very little, Serrago said. Firing accuracy, consistency and predictability has divided into two price-driven groups.

“While manufacturers on both ends of the divide have been adding features to expand ease of usability, those at the lower end have done little to advance furnace performance and narrow the performance gap with the high end furnaces,” he said. However, there have been some recent innovations in muffle and electronics designs that have produced products that have broken the traditional price versus performance gap.

Product Spotlight

Programat Furnaces

The Programat Second Generation (G2) features Power Saving Technology, which allows the furnace to power down when in the stand-by mode resulting in reduced power consumption. The P700/G2, P500/G2 and the P300/G2 all contain 120 factory-set programs for Ivoclar materials and additional customizable individual programs for other materials. Both the P700/G2 and the P500/G2 have color touch screens and operating status displays. Ivoclar Vivadent’s Press/Firing combination furnaces, the EP5000/G2 and the EP3000/G2, feature Power Saving Technology, and CDS (Crack Detection System). This system immediately interrupts a press process if a crack in the investment ring occurs. The furnaces include 130 factory-set programs for Ivoclar materials and an additional 500 firing and 20 press customizable programs for the EP5000/G2 and 300 firing and 20 press for the EP3000/G2. All of the company’s firing and press furnaces have QTK (quartz tube kanthal) muffle technology for even heat distribution.

Ivoclar Vivadent

800-533-6825 | ivoclarvivadent.com

Testimonial

Jeff “JD” Henderson

Utah Valley Dental Lab - Provo, Utah

Why does your lab choose to use Ivoclar Vivadent’s Programat furnaces?

Our lab produces primarily Ivoclar restorative products, which means we follow the prescribed production parameters set forth by the materials. Using Ivoclar ovens creates consistency with our products. We can tell our customers our products should meet the manufacturer’s specifications for durability because we followed their instructions.

What are the biggest benefits of these furnaces?

Few manufacturers make both ceramics and the equipment to manufacture them. That relationship creates a level of accountability that isn’t present with other companies. It also creates a relationship with the company, and Ivoclar has been great to work with. Their technical support and customer service are terrific. Loaner furnaces always have been available when repairs are needed.

How do the furnaces fit into the everyday operations of your lab?

The low-profile clamshell design works well with the layout of our workbenches creating a more ergonomic function and a cleaner, less cluttered look to our laboratory. As owners of several dozen ovens, it makes sense to have them all be from the same manufacturer. It creates consistency throughout the laboratory and a familiarity with all our technicians, wherever they sit.

Product Spotlight

ProPress SP

A component monitors flow of the glass and senses movement of the ceramic into the ring in real time in the ProPress SP Furnace. When the mold is filled, the table is lowered as quickly as possible. The fast press saves time and prevents or minimizes formation of the reaction layer. The furnace also can press split (cracked) molds and is thus can successfully press more units per ring, faster and more consistently.

Whip Mix

800-626-5651 | whipmix.com

Testimonial

Tim Tyndall, CDT

Creative Expressions Dental Lab - Winterville, N.C.

Why did your lab choose to use Whip Mix’s ProPress SP furnace?

Certainly with any furnace, consistent firing temperatures are going to be the key factor. That’s going to be my first consideration, then ease of use while pressing and the simplicity of the programming. The determining factor in the accuracy of this furnace really goes back to the quality standards of Whip Mix itself.

What are the biggest benefits of the furnace?

With ProPress SP, one of the really great features is that when I take a ring out of the burnout furnace and it has a fracture in it, I actually have the option to tell the furnace to intervene. It will reduce the pressure and allow the ring to be pressed where it normally could be a failure. The ability of the furnace to sense a complete press is impressive and it works with all glass products on the market, including lithium disilicate. The average pressing time for lithium disilicate is 55 seconds or less, thus reducing reaction layer and divest times. The LED panel on the front of the oven allows us to monitor progress of all firing and pressing cycles. The consistency of desired results is the biggest benefit of this furnace.

Has the furnace been a solid addition to your lab?

Absolutely! Whip Mix’s quality standard is well known in the industry as well as their customer service. They’re very competitive for the quality and features you get. Whip Mix is the first place I’m going to look when purchasing a furnace. I have yet to buy a Whip Mix furnace that doesn’t meet the standards they advertise it to be. The SP furnace is a real production pressing furnace that’s extremely accurate. It’s a real workhorse and I believe it’s the best pressing furnace and the best value on the market.