Sintering Furnace Maintenance



Be honest, when was the last time you cleaned your furnace? It’s your workhorse and arguably just as important as your milling machine. Your furnace accuracy has a large role on the quality of your restorations and if you are not properly maintaining it, you are putting your final work at risk.

Here are some of our top suggestions on determining whether it’s time for a clean.


Have you noticed a change in the appearance of your final zirconia restorations? A discrepancy or change in shade is a strong indication of a sintering issue.

Acid Stains

Green state colorants before sintering the acid (found even in water-based liquids) can have a negative impact on your furnace heating elements and thermocouple. It can change the temperatures for the sintering cycle and discolor your restorations.

Degassing or Cleaning Cycles

This is an important process in extending the life of the heating elements and thermocouple and ensure high quality sintered restorations.

Add an absorbing powder to the sintering tray prior to running the cleaning cycle. This material is specifically designed to absorb contaminants from both the heating elements and thermocouple. Keep in mind SiC heating elements do not get contaminated, thus, require no cleaning cycles.

If you are using green state liquids and the furnace has MoSi2 heating elements, you should run a clean cycle weekly. If you are using pre-shaded or multi-shaded discs, a cleaning cycle should be done twice a month.


All sintering furnaces should be calibrated over a period of time.

Depending on the manufacturer and the internal components, this should be a monthly, quarterly or bi-annual standard maintenance.

Bottom Line

Maintaining a clean furnace is just as important to the final esthetics of a restoration as the zirconia you choose to mill. It is important to read the instructions before use, understand the furnace and to keep an eye on the condition of your furnace.