For many years I have been using Sonicare Advance A4100 power toothbrush with A-Series brush heads. The toothbrush worked great for me and I had no particular complaints about the A-Series brush heads either. They did require periodic cleaning, otherwise toothpaste accumulation caused an unpleasant substance to form inside the brush heads' bases and the toothbrush's handle's top part.
Recently I got the new Sonicare Essence e5500, which uses E-Series heads. I also bought some extra replacement E-series brush heads. To my surprise I discovered that their packaging indicated that they "now work with A-Series handles". I wish I had known earlier, and here is why.
Is E-Series an Improvement Over A-Series?
Not only these brush heads work perfectly with the ne E-Series (or e-series) handle (I use e5300), they work with my A-Series handle better than the A-Series brushes. Mostly.
The E-Series brushes have somewhat longer, but more slender neck, which is angled and, just as the product advertisement says, helps it reach better. Yes, to those, so-called, "hard-to-clean" areas. Nice!
The A-Series heads had a thicker neck, which was also straight and seemingly shorter. They were definitely not as good in reaching the "areas". Rear surfaces of the furthest teeth and such.
Also, somehow the E-series heads feel like they clean better and produce stronger vibrations. This is always the case when replacing older heads with the fresh ones, but only to some extent. This time, the extent is more significant.
The bristles themselves have more curved arrangement, which is probably a good thing.
These are the positives. However important they are, I have to mention the negatives as well. First of all, the E-Series brush heads are marginally more expensive than the A-series. The difference is microscopic and since they work better, the question, of course, is "who cares?" I don't.
Then, they are somewhat more cumbersome to put on the A-series handle, because you have to align the front of the brush with the front of the handle perfectly. A-series heads were easier in this respect.
Then, there is a question of cleaning up. Despite having some soft material in the top part of the joint between the brush's neck and its "nut", or whatever you want to call the part that attaches to the handle, the toothpaste reliably collects in the area between the brush and the handle on each ingle use. A-series heads were made completely of hard plastic and they collected seemingly less. Fortunately, the new brush heads are easy to rinse.
Then, which is neither here nor there, there is a question of the replacement interval. The new heads came in a package that indicates that they need to be replaced every 3 months for best results. The A-Series used to came in a package indicating 6 months. Although I definitely felt that they were not cleaning as well as new much earlier than that. I cursory online check reveled that both kinds of brushes now recommend 3 months. Works for me.
The E-series heads have solid construction and feature differently-colored bands around their necks, which helps one differentiate his/her brush from the others'. The heads are made of plastic, which is seemingly whiter than that of the A-Series heads. A-Series heads look like an anachronism in comparison to the new E-Series ones.
Pros: Fit E-series and A-series handles, excellent cleaning and comfort, reach far and well
Cons: Need to clean after each use to avoid buildup of toothpaste and other stuff
Whether you are using an A-series handle, or an E-series one, the E-series replacement brush heads are awesome. I will keep using them and replace at 3-month intervals, while rinsing after each use. Highly recommended.