I purchased the Oral-B professional care smart series 4000 toothbrush a few years ago and am extremely happy with the results. This toothbrush has a lot of power and thoroughly cleans my teeth each time I use it. The charge on the unit last a long time. I highly recommend this product. Performance/Cleaning The Oral-B professional care smart series 4000 toothbrush performance and cleaning attributes are amazing. It's a powerful unit that provides excellent results. My teeth feel so clean and fresh each time I use it. This electric toothbrush doesn't even compare to my old manual toothbrush. It cuts down on plague significantly. Durability I have owned this unit for several years. It's so easy to maintain. You can purchase the Henry feels actually local grocery or drug store. Kroger carries a generic replacement head that fits this unit. My Oral-B professional care smart series 4000 toothbrush is still going strong.