ZIRCONIA DISCOLORATION AFTER FIRING
One of the more common issues we hear from dental sintering folks who use MoSi2 elements is the discoloration of their sintered Zirconia product.
Broadly, the discoloration is caused by contaminants bonding with the Zirconia. More specifically, the discoloration is caused primarily by Iron and Molybdenum leaching out of the elements and into the furnace environment.
Preventing Iron leaching is a relatively straightforward process – don’t buy cheap MoSi2 elements! Sarcasm aside, this is a good guideline to follow. All MoSi2 elements will have trace amounts of Iron present as a contaminant, but the best and most pure elements will relegate Iron to trace amounts rather than problematic amounts.
As the saying goes – you get what you pay for. Although it is tempting to look on Facebook or other sourcing sites for cheap MoSi2 heating elements, you can easily find suppliers who can provide it by 45-100usd, but the fact of the matter is that high-purity MoSi2 elements are difficult – and relatively expensive – to manufacture. There are only a handful of reputable manufacturers in the world for these types of elements, it has taken them decades to perfect the manufacturing of high-purity MoSi2 heating elements. Lucky, Vsmile is cooperating with one of them, which gives us a chance to provide you the most pure MoSi2 heating elements in the world.
As far as Molybdenum contamination goes, this one is a bit trickier. As previously mentioned, MoSi2 heating elements form a protective Silicon oxide layer. These two materials work well together, but there is a bit of an inherent challenge in high cyclic applications such as dental sintering since Silicon heats and cools at a different rate than Molybdenum (they have different Coefficients of Thermal Expansion). Over time, the Silicon builds up on the surface of the Molybdenum, and as it grows thicker, it begins to crack and flake off of the element and into the furnace environment.
As the Silicon flakes, trace amounts of Molybdenum come along with it, causing contamination. after years of hard work, Vsmile designed the super-high purity mosi2 heating elements for dental furnaces, specifically to form thinner oxide layers in high cyclic applications – and that can combat this issue, help you to achieve the best result of the Esthetic zirconia sintering. Now got got heating elements for Ivoclar S1 , Shenpaz SINTRA and SINTRA PLUS, Sirona Infire HTC Speed, Vita Zyrcomat 6000MS, Sirona Multimat2Sinter， Vita Zyrcomat, DentaStar P1,Nabertherm LHT 02/17LB Speed, Ivoclar Vivadent Sintramat, ZIRKONZAHN 600,3M Lavatherm (Model 33500072989/00/1/00), The most important thing is we can customize the size for your furnace if you can provide us the specific data.
The last note: due to the sales volume of these elements we do not stock them and they are a 4-5 week lead time.
For more information. please contact us.