Efficient but if you have a lot of heavy tarter you won't get same results as a dentist office [SEP] This will help between cleanings by a dentist office but don't expect it to replace regular cleanings.  It takes time and will work on lighter surface tarter or plaque.  The reviews saying it took off chunks of plaque is misleading, it isn't that powerful but it also isn't as weak as some of the other 1 and 2 star reviews indicated it was.