Curing Machines and Methods〈 Q&A 〉 » Back

Q1: What curing machine do you recommended as best?

You should face no particular problems if you use a dental-materials curing machine with an emission wavelength of 400 to 500 nm. However, we cannot recommend curing machines with only fluorescent tubes, because the illumination intensity is too low for curing.


Q2: In general, some composite resins can be cured in a much shorter time with a xenon light-curing machine. Is it possible to cure TWiNY in a shorter time in this way?

A xenon light-curing machine cannot be used to shorten the curing time of TWiNY. Apart from the intensity of the lamp illumination, a wide range of factors has a complex effect on curing resin. These include emission wavelength, angle, quantity and deterioration of lamps and the temperature inside the curing machine. Therefore, it is not enough to simply say “a xenon light-curing machine can shorten the curing time” without taking these other factors into account as well.


Q3: If the material is light-cured in a vacuum,
can its hardness be increased compared with normal light curing?

Creating a vacuum or pressurizing the environment makes it oxygen-free and reduces the uncured surface, so the hardness will be enhanced. However, “Air Barrier” provides the same effect with sufficient hardness.


Q4: General composite resins need to be heat-cured immediately after the final light curing.
On the other hand,why is TWiNY recommended to be heat-cured after shape modification?

In cases where additional layering after heat curing is needed again, heat curing should be done again even though the amount of additional layering is small. TWiNY is designed to be heat-cured after shape modification. TWiNY can be heat-cured any time after final curing; therefore, it is possible to heat-cure for a number of different patients at the same time. If it is necessary, there is no problem in doing additional layering after heat-curing. For additional layering, please check that there is no residual Resin Air Barrier left, and follow the instructions manual for additional layering.


Q5: What heat-curing machine do you recommend as best?

There is no specialized heat-curing machine only for TWiNY. We recommend a range of commercially available heat-curing machines. The heat-curing settings for TWiNY are about 110℃ for 15 min. The major heat-curing machines are given in the following table:

Manufacturer Product name Temperature (℃) Time (Min.)
GC Corporation PETITOVEN Approx. 110 Approx. 15
J.Morita Tokyo
Manufacturing Corp.


Approx. 17
Kuraray Medical Inc. KL-400 110 15
Tokuyama Dental

The heat-curing settings for PETITOVEN (GC Corporation) and KL-310 (J.Morita Tokyo Manufacturing Corp.) have already been set and cannot be adjusted. The 4 machines above provide adequate heat-curing conditions for TWiNY. 


Q6: For heat curing, is it all right to put material in boiling water or place it in a furnace or a microwave oven, wrapped in tinfoil?

We cannot recommend these methods because they may cause unexpected problems in terms of material properties and shade.


Q7: According to the instruction manual,when we are heat-curing Inlay, we should remove the Inlay from the plaster model and then heat-cure it. Why should the Inlay be removed from the plaster model first?

Heat curing with the plaster model makes the plaster model brittle and cause fractures and breaking. This is not only for Inlay; please avoid heat-curing the plaster model in all cases.


Q8: Is the curing schedule for TWiNY different from other indirect composite resins?

The light-curing time is same as for Ceramage (Shofu, Inc.).
For your reference:
GRADIA FORTE (GC Corporation) Preliminary curing: 30 sec.; Final light curing: 3 min. ESTENIA C&B (Kuraray Medical, Inc.) Preliminary curing: 10 sec.; Final light curing: 5 min. The heat-curing time for both GRADIAFORTE and ESTENIA C&B is 15 min."


Q9: How many times can heat curing be done at a maximum?

There is no limit to the number of times heat curing can be performed. The material can be heat-cured repeatedly, as needed. However, the operating time will become longer, so we basically recommend heat-curing one time after additional layering and shape modification


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