3 Must-Haves in Long-Lasting Milling Tools

During the last few decades, dental supply manufacturers from all over the world have introduced many different types of dental raw materials. Some did well initially but eventually faded, some never saw the light of day, and some skyrocketed, specifically zirconia. Today, all things considered, zirconia is the best material for dental restorations.






What Is Zirconia?


Zirconia consists of zirconium dioxide, which has the highest mechanical strength and fracture resistance of all non-metallic materials. Besides the strength, the other main reason it is widely favored in medical devices is due to its superior surface smoothness. In addition to medical prosthetics, zirconia has been widely used across industry and markets in such products as watches, knives, jewelry, valves, gears, and pumps, to name a few.


 


Zirconia in Dentistry Today


Zirconia is the most recent arrival in dental materials. It only became popular when CAD/CAM was introduced in the dental laboratory process in the 2000s. Until about 2009, when gold prices soared, zirconia had only a small share of the market in dentistry. Then, as an alternative to expensive gold crowns, dental zirconia ceramic became a more popular choice among restorative dentists.


If multilayer?zirconia is the best material, then why wasn’t it used much before? It’s simple. Most mom-and-pop local dental labs could not afford to invest in high-tech, computerized, advanced CAD/CAM systems. Additionally, most of those small labs did not have the skill or knowledge to use the new technology.


 


Three Popular Variations


Most zirconia in the market today shares a very similar composition. However, the manufacturing process differs slightly depending on the purpose of the zirconia. For example:


Solid or monolithic zirconia with full compressed blanks to get the maximum strength (1,100 to 1,200 MPa)


Lightly compressed zirconia to accommodate medium translucency of anterior restorations (700 to 850 MPa)


Full zirconia framework stacked with zirconia powder (layered zirconia) to accommodate maximum aesthetics for anterior translucency


 


There are many different types of zirconia for dentistry today, and it’s confusing because of the many brand names. I receive many calls from our clients asking about this brand and that brand, but my answer is always the same.


Regardless of what they call it, most zirconia shares a similar composition. However, it differs according to the manufacturing process, which affects two main characteristics: strength and translucency (or opacity).


For example, the opacity of the dental zirconia blank is directly proportional to the strength. In other words, the strongest zirconia blanks are the most opaque they will be. Therefore, if you need the highest translucency (the least opaque blank) for your anterior restorations, the strength is significantly compromised. Still, it may be stronger than other non-metallic dental raw materials.


 


Why Dental Zirconia Is the Best Material


There are three reasons why zirconia is the best material for dental restorations, primarily based on a comparison of metal-containing products, such as porcelain fused to metal, a full metal crown, and titanium. By comparison, zirconia is much more aesthetic, lasts longer, and is even more biocompatible. However, there are a few downsides as well.


 


Unless you are closely involved with the dental sector, you may not know that acrylic polymers (PMMA or Poly Methyl Methacrylate) are essential in creating the very highest quality, lasting solutions for dental procedures.


Statistics show that there are huge percentages of the population in Europe and the Americas with missing teeth and affected with oral disease. According to the WHO, (World Health Organization), around 30% of the population aged 65-74 has lost their natural teeth while 60-90% of school children worldwide have dental cavities. Add to these factors an increasing consumer awareness of oral health issues and a rapidly increasing population and it is clear that there is much evidence to suggest that the global dental products market is set to grow significantly.


For over 65 years we have been working closely with global market leaders and academic communities to build on our knowledge in the dental sector to develop leading edge dental PMMA.






If you have braces you may find that they rub against the insides of your cheeks or lips. Sore spots on the inside of your mouth can develop because of this, especially in the first days and weeks of you wearing braces. The best way to treat this is simply by applying a little dental wax to your braces. The wax helps to make a barrier between your braces and your lips, cheeks, tongue and gums. The wax is easy to apply and will most likely have been supplied to you by your orthodontist.






In the past several years, the use of zirconia restorations has become increasingly common. Due to the increasing number of prescriptions for zirconia restorations, more laboratories are purchasing milling machines to mill the copings and crowns in-house. After learning how to use the mill, most dental laboratories seek to increase and maximize productivity with the milling machine. To help with this goal, laboratories need to consider three aspects: the use of the right materials, proper nesting, and tooling. This article focuses on the third aspect—milling tools and three features that add value.


The second aspect is the coating. When milling zirconia, using diamond-coated tools will significantly extend the life of the milling burs. We manufacture all our milling burs with the highest-quality materials. The diamond coating that Primotec uses is a proprietary chemical diamond formula, making the tools last up to 10 times longer than standard carbide burs. Finding high-quality zirconia that is not too hard in its pre-sintered stage will also help increase bur life drastically.


The flutes are the third aspect. Most milling tools on the market use only two flutes. Our burs use three flutes, which means 50% more cutting surface than those with two flutes. This point alone can add as much as 50% more life. Also, we notice that the milled restorations are even smoother than those produced with only two fluted tools. If you want to increase your feed rate, that additional flute helps in removing the material at a quicker rate, maintaining a quality surface finish.