Heaterconductor made of molybdenum disilicide (MoSi) – The silicon contained in it forms a glass-like protective layer on the surface of the heatsealing band and thus prevents oxidation of the molybdenum. Over time, crystals of silicon dioxide, SiO2 or quartz form in this molten glass, which grow into islands and eventually cover the entire surface of the heatsealing band. A frequent cause of this is that in standard sintering programs the heatsealing band often remains below its performance limit or does not reach the maximum temperature. Due to temperature changes of the heatsealing band from "cold" to bright red glowing within seconds, these crystals are subject to high mechanical stresses during heating processes. Isolated microparticles are blasted out and thrown into the furnace chamber. A single SiO2 particle is sufficient to produce a strong yellow coloration on zirconium oxide over a large area.

Another danger During the sintering process, silicon ions dissolve out of the heat conductors and enter the furnace atmosphere. Due to the high temperature in the firing chamber, the silicon is converted into a gaseous aggregate state and thus reacts with the zirconium oxide restorations. Yellow-green discolorations on the surface of the restorations are the result after sintering. This problem does not arise with silicon carbide (SiC) heat conductors, as no particles are released into the furnace atmosphere, causing discoloration of the sintered material. Furnaces with these heating conductors have the advantage that the restorations can be sintered without a sinter tray lid. In direct comparison to molybdenum disilicide (MoSi) heating elements, the entire energy can be introduced into the sintered object here, such as emerging thermal radiation, which is otherwise attenuated by the use of the cover.