Philips Sonicare Elite+Sonic electric toothbrush

How often should I replace my Philips Sonicare Brush Head

Which brands/brush heads fit in the Sonicare Sanitizer?

How do electric and manual toothbrushes differ?

How does the brushing guidance work in the Sonicare app?

Why is there a gap between my brush head and handle?

My brush head is difficult to attach or remove.

I cannot connect my toothbrush to the Sonicare app

My brush head falls off my Sonicare toothbrush

My Sonicare toothbrush turns off by itself

My Sonicare toothbrush is vibrating less powerfully