basics of alginate
what type of impression material is alginate?
Irreversible Hydroid
What temperature of water makes alginate set faster?
Warm water
What must a tray do before taking an impression?
Fit properly and cover all teeth
Which arch is usually taken first?
Maxillary (upper)
What must be done immediately after removing the impression?
Rinse under water
what is the primary ingredient in alginate?
Sodium alginate
What temperature slows the setting time?
Cold water
What is placed in the tray to help alginate stick?
Adhesive
What should the patient do while taking a maxillary impression?
Lean forward and breathe through nose
What is the next step after rinsing?
Disinfect according to guidelines
Why is alginate called “irreversible”?
Because once it sets, it cannot return to liquid form
How long does alginate usually take to set in the mouth?
About 2–4 minutes (depending on type)
How far should the tray extend in the posterior?
Cover the last molars completely
How should the tray be seated in the mouth?
Posterior first, then anterior
Disinfect according to guidelines
NO
What happens if too much water is added to alginate?
Weak, runny mix and distorted impression
What is the correct motion when mixing alginate?
Figure-eight motion against the bowl
Why is selecting the correct tray size important?
Prevents distortion and ensures full coverage
What causes voids (bubbles) in impressions?
Air trapped during mixing or improper seating
Why must alginate impressions be poured quickly?
They shrink due to syneresis and distortion
What are alginate impressions primarily used for?
Study models, orthodontic models, bleaching trays, mouthguards
What happens if alginate is under-mixed?
Grainy texture and weak impression
What could happen if the tray is too small?
Missing anatomy and inaccurate model
When removing the tray, how should it be taken out?
Quick snap to reduce disortion
What happens if alginate sits too long before pouring?
Dimensional changes and inaccurate model