Table 2.

Comparison among studies that evaluated different slow cooling methods.

Author, year (Ref)	Label used	Description of the cooling rate	Porcelain	Tg (°C)
Al-Amleh, 2014 [8]	Slow	Cooling at 20 °C/min from final glaze temperature (725 °C) to 400 °C.	IPS e.max ZirPress	530
			IPS e.maxCeram	490
Belli, 2013 [9]	Slow	At final glaze temperature, the door of the furnace was opened only 10%, until the temperature reached 200 °C.	VM9	600
			Lava Ceram	565
Benetti, 2014 [10]	Slow	The chamber was kept closed until the furnace reached 50 °C below the Tg.	Lava Ceram	557
			Vita Omega 900	594
			VM9	600
			Zirox	570
			Lava Ceram	565
Tan, 2012 [14]	Slow	The specimen was left in the partially (30%) open mufffle for 15 minutes until a mufffle temperature of 500 °C was reached.	VM9	600
Mainjot, 2011 [13]	Slow	Cooling at 2 °C/min in a special furnace (Carbolite LMF 12/2, Carbolite, Hope Valley, UK), from 900 °C to room temperature.
	Modified	Cooling from 900 °C to 600 °C with furnace closed.
Choi, 2011 [11]	Slow	The furnace was kept closed from final sintering temperature to 100 °C. Which took approximately 30–40 min depending on the firing cycle used.	Vita PM9	640
	Normal	The furnace was kept closed until temperature drops to the starting temperature of the glazing cycle.	IPS e.max Zirpress	530
			Wieland Xzr	620
			CZR	615