Now, this leads me to one of the biggest problems with the Oral-B Smart 4000 and that is the box contents. The variant with the case is primarily sold via Shaver Shop for the same price as the one without a case.

Ideally, a way of selecting the mode prior to actually turning the brush on would be the solution. This is not available, not even on the premium Genius 9000 model. Another small but significant thing to remember is; put the brush in your mouth before powering on and changing modes otherwise the toothpaste might go flying across the room. Each of the 3 cleaning modes work slightly differently, with differing levels of oscillations, rotations and pulsations to achieve different cleaning effects on the teeth.Aside from the aforementioned 3 brush heads, the Smart 4 comes with a brush head storage compartment included in the box.

The very nature of being an electronic item with moving parts does indeed make the brush susceptible to failure. However, the reliability of Oral-B products tend to be very good. Design aside, they do the same job. When the sensor is activated they both light up red to alert you that you are brushing too hard. Reduce the pressure and the lights go out. Using a free app available for Android and iOS you can connect the 4000 wirelessly to your smartphone.

Here at Electric Teeth, we like to calculate the approximate cost of ownership over a 3 year period to try and give you a guide to what it would cost, as well as a benchmark for other brushes. You can find much more detail on each mode and how they compare in our article, Oral-B cleaning modes explained. The main feature of the app is the on screen timer and guide that shows you where to brush and how well you have brushed. At 30 second intervals, the brush will provide an audible warning via a slight pause in the brush motor at to tell you to change quadrant. Once the 2 minutes are up 3 brief pauses in the brush motor will be heard and felt.

The charging stand is fairly self explanatory, but I explain more about this in the battery section of the review. Both brushes have the same cleaning modes available, but the brush heads that come included does differ slightly. Buy the Genius 9000 and although you have to power the brush on to change the cleaning mode, if you have changed the mode, it will remember it. Next time you power the brush on, it will begin in that mode. The Oral-B Smart 4000 CrossAction electric toothbrush does not do this.Just relieve the pressure and the light will go out and the motor power up again. Just remember to let the bristles essentially glide across the tooth surfaces.