Differences in
dental sintering furnace are not just based on brand and price.Heating elements,numbers of programs,sintring speeds,and even unit size all very important.So which unit is best for your dental lab?
The driving force behind newer furnace designs and capabilities is the growing number of zirconia materials and their required sintering parameters.Most zirconia materials are sintered at or below 1550℃ with a slow heat rise(4℃-10℃ per minute).Some zirconia manufacturers are recommending lower temperature and some higher.
Proper Temperature
It should be noted that recent studies indicate that firing at approximately 1500℃ (depending on the temperature accuracy of the furnace) produces maximum strength in zirconia and that firing above and below the recommended temperature by just 150℃ can result in lower strength due to grain growth.A specific case in the study showed that strength drops from about 1280MPa at 1500℃ to about 980MPa at 1600 ℃ and only about 600MPa at 1700℃.
In addition,a higher temperature may result in lowered stability and uncontrolled transformation,causing cracking of the zirconia.And that’s just the physical property changes.Temperature that are too high for the material also cause a lowering of translucency.Higher is not always better!Sticking to the manufacturer’s recommended sintering curve is critical.As long as the manufacturer is reputable.Most yttria partially-stabilized zirconia materials attain their ideal physical,mechanical and esthetic properties at approximately 1550℃
Heating element
Kejia Furnace provides the highest quality “u” shaped nodiscoloration heating elements in the market.It is specially designed for the zirconia sintering.The quality is consistently controlled and with temperature up to 1800℃ with long lifetime.
And it is optimized for sintering full zirconia delivers highest transluency.
Molybdenum disilicide (Mosi2) heating element is a resistance generate-heating component made from Mosi2 or the basic material.It is used in high temperature under the oxidizing atmosphere.It looks like glass in its surface and form a light SiO2 glass film which can protect the element not to be oxidized.So this kind of element has unique effect for resisting oxidization in the high temperature.
Programs
If you are using more than one type of zirconia----Or you are looking for varied results,depending on the patient,where in the mouth the restoration will be placed,etc.you will most likely want to purchase a furnace that offers you multiple programs,And even more importantly,multiple program stages.
Program stages enable you to vary temperature,delayed starts,ramp rates and hold tomes to adjust your final result.Since most sintering cycles are fairly long,you may want to increase the rate rise from ambient temperature to the point where sintering begins,then throttle back in a subsequent stage to optimize the translucency.
Here is the screen of KJ-M1700-DL(16 Program stages with 16 sintering curves)
Safety
Of all the features a
dental sintering furnace may offer,perhaps the most important one is safety.After all,these furnaces climb to extraordinarily high temperature and they hold there for a long time.And they use high amperage to do it.If you are concerned for the safety of your personnel and laboratory. Be sure to buy and use a furnace that is CE certified.This means that an independent testing laboratory has confirmed that if the the equipment fails etc.It will do so safely.You have several good choice our there.When you’re ready to purchase one,refer to this article when you’re shipping for a good,effective and safe sintering furnace for your lab.
Kejia Furnace,there are high cost-effective on our
lab furnace and
dental furnace.