Almost every practice I visit uses alginate to take impressions.
Frankly, if you are currently using alginate, then I think you are doing yourself a big disservice.
Please let me go through the list of the problems that I find with alginate:
- It's time consuming to get ready
- It's messy to mix and leaves a dirty bowl and spatula that must be cleaned
- If the quantities of powder and water are not precise (and the quantities are difficult to get right) you either get a bowl of unusable slop or a rubbery mass that sets before you can get it in the patient's mouth
- If the water is warm it sets like lightening or if the water is icy cold it takes ages to set
- It's messy and crumbly in the patient's mouth and most people hate it
- Once set it must be kept moist and poured promptly or else to will distort and produce an inaccurate model
- If left on the model too long it dries out and will break the model during removal
- It can only be poured once. If that model gets ruined then there is no way to try again
Alginate does have one virtue. It's relatively cheap.
Putting up with all those problems just to save a couple of dollars for each impression is false economy.
PVS materials have none of the drawbacks mentioned above. They're well tolerated by patients, quick, clean, easy, consistent, forgiving and reliable.
If we'd had PVS materials for years and alginate was invented today I think that alginate would be rejected as being a hopeless material. It's just that most dentists grew up with alginate and have become blind to its failings.