For alginate you need to collect Majority of the powder or it will be too runny. Easier if you use the whole bowl surface to collect it.
Read the instructions because theyll ask for a certain tray. trays are different sizes so you may need 3 scoops to 3 water
Cement is usually 2 level measuring spoons to two drops. Make sure measuring spoon is dry also. Should be more of an icing consistancy like if you touch it with your spatula it stands at a peak if that makes sence
GIC is slightly more than a level scoop but still 2:2 ratio. Use spatula to collect and place on side of mixing mat
The rule is to follow the manufacturers instruction when it comes to ratios, however sometimes the dispensing can go wrong. In the exam, it is important to get the mix right, but if you get it wrong, you should also be able to explain why it may have gone wrong, and if you have time, have another go.
Alginate - are you using the correct scoop and measuring cup? have you shaken the alginate box? when you scoop the powder are you pressing it down once with the spatula then levelling it? is the water exactly on the line , check on a flat surface.
Cement, GIC, Eugenol etc - again, follow the recommended measurements , but remember, sometimes the dispensing can go wrong. With the powder, divide it into sections with the spatula, then mix it into the liquid bit by bit, if the mixture is too wet, don't use all the liquid, they want to see that you know the consistency should be as well as being able to follow instructions.
I'm due to sit my exam end of Jan. We don't do alginate impressions at our practice but we do have some in stock so I have been practicing mixing it. I do 2 scoops and 2 measurements of water and it's always a bit too runny. I heard in the exam you MUST stick to 2 and 2 for the measurements.
As for cement...How do you know the ratio of all the materials. I'm aware of GIC that 1 powder to 1 drop...but when I mix it, it never seems to be in the consistency where I can shape it in to the sausage shape to present it to the examiner. At our practice we mix it then roll it with our hands to give to the dentist...however I've been told you can't use your hands to do this in the exam.
I know there will always be a mixing station and I'm getting worried!!