Instruct: Classify the given Amazon review into positive or negative sentiment.
Query: Water Pik

this is my 2nd Waterpik and I love it. Dentist says my gums and teeth have greatly improved. I would definately recommend this. I even bought one for my friend and she sees the difference. I ordered it from Amazon and received it very quickly. I have never been disappointed in any deliveries I receive from them. Sometimes they come before the scheduled delivery date. Keep up the good work Amazon!