PFM crowns and bridges

I spoke recently with Rudy Ramirez, manager of the PFM (Porcelain Fused to Metal) department at Glidewell Laboratories.

I spoke recently with Rudy Ramirez, manager of the PFM (Porcelain Fused to Metal) department at Glidewell Laboratories. With more than 30 years of experience in the dental lab business, he has a wealth of knowledge about the evolution and current state of PFM crowns and bridges, which still comprise the majority of crowns and bridges in the field. Rudy’s department is larger than most labs, so he sees a wide cross-section of dentistry. Following are excerpts from our conversation.

M:Some lecture circuit speakers predict the demise of using metal in the mouth. Are you worried about the extinction of PFMs?

R: No, at least not in the near term. For years, every new all-ceramic system predicted it was going to replace PFMs. While these all-ceramic systems enjoy a time of success when everyone jumps on board in the beginning, dentists eventually start experiencing technical problems and see failures. A lot goes back to tried-and-true PFMs. Today, we’re seeing PFMs go through the roof in terms of acceptance. For instance, Captek offers biocompatibility that others don’t provide.

M:Among the crowns fabricated at Glidewell, what percent are PFMs?

R: About 80 percent. There is a lot of noise surrounding all-ceramics. Many people are talking about them. But the reality is that today you can’t find an economical all-ceramic. Dentists we talk to express their concerns about price pressure. They’re not asking which is the best all-ceramic to use. There needs to be a solution. That’s why we are developing the Newport system, which utilizes pressed-to-metal technology. We believe it provides high-quality, consistent restorations at an affordable price. The issue of price prohibits some people from seeking dental care.

M:I learned about Captek because I was looking for the most esthetic PFM I could find. While I’m comfortable using all-ceramic restorations in certain situations, such as veneers for full-coverage restorations, I still want the confidence that PFMs provide. Tell us more about your experiences with the product.

R: When I started with Captek approximately 14 years ago, the product began humbly. It was viewed as a “boutique” product for single anterior restorations only. Working together with company executives, we brought the product to the mainstream. We wanted to show what it could do everywhere. Today, we use Captek for single units, bridges, and large cases. It’s the most prescribed brand of crown that we do at Glidewell.

M:Regarding PFMs in general, what are the biggest problems you see when dentists send in cases?

R: General problems include insufficient occlusal reduction and bad impressions. These problems are no different than what you would have with all-ceramics. A unique problem is that doctors don’t seem to have a good grasp of the technology. Their expectations are unrealistic. Many seem to think that once you prescribe a PFM, there are no more rules.

M:What significant advances do you see in the future?

R: Pressed-to-metal and automation. NetPress will be a significant advance in terms of consistency and economics. It involves a different way of making a crown. While still a PFM, its manufacturing process is much more predictable. It is easier to train technicians using this method versus traditional methods. Also, the anatomy is more consistent. I had a doctor take a tour of the lab recently. He saw the NetPress process and how consistent the anatomy was from crown to crown.

M:Would it be easier for technicians to make esthetic PFM restorations if more dentists provided digital photographs?

R: Absolutely. These photos have limited use in terms of shade, but they are great for viewing the mouth. We can use digital photographs to see if we have achieved what the dentist is seeking. But dentists have to be careful. Intraoral pictures can cause problems. Doctors can e-mail digital photos to fixed@glidewell-lab.com.

M:Speaking of shade, I am more reliant on digital shade-taking systems. What is the lab’s view?

R: Digital shade-taking systems are a definite help in the lab. We use Vita Easyshade to QC our restorations before. Then, afterwards we use stain and glaze. The doctors who use Vita have fewer shade remakes. It’s not that these systems are always the best approach, but they are often better than relying on the human eye. At times, we get cases in which a doctor asks for a completely different shade from what he originally requested. The environment may have been wrong, or the shade may have been misread. Digital systems remove the human factor. You simply shoot a tooth, and the system tells you the shade.

Dr. Michael DiTolla is the Director of Clinical Research and Education at Glidewell Laboratories in Newport Beach, Calif. He lectures nationwide on both restorative and cosmetic dentistry. He also teaches hands-on courses on digital photography and digital image-editing for the entire team. Dr. DiTolla has several clinical programs available on DVD through Glidewell. For more information on this article, or for more information on receiving a free copy of one of Dr. DiTolla’s clinical DVDs, e-mail him at mcditolla@mac.com, or call (888) 535-1289.

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