Short answer
The ADA notes that people with dental appliances such as braces may find a powered brush easier to use. The features that match the usual advice are a pressure sensor and a gentle mode. Your orthodontist or dentist decides what is right for your appliance; this site does not.
The ADA's toothbrush guidance says both manual and powered brushes remove plaque effectively, and that people with dental appliances like braces may find a powered brush easier to use. It does not recommend a particular design for braces or implants, and neither does this site.
If your dental team has told you not to scrub hard and to clean carefully around brackets, bridges or implants, the features a maker can list that correspond to that are a pressure sensor, a sensitive or gentle mode, and a head designed for orthodontic work or between-teeth cleaning. Oral-B, Sonicare and Waterpik each sell specialty heads for some handles; check the maker's head range for the specific handle.
Water flossing is a separate question. The Waterpik Sonic-Fusion in this catalog combines a brush with a water flosser; whether water flossing suits your appliance is one to ask your dental team.
The guide to brushes for braces and sensitive gums lists every model here with both a pressure sensor and a gentle, sensitive or gum mode, cheapest to own first. It is built from features, not outcomes.
Maker claims quoted on this page are the maker’s own and are labelled as such. This page is general information, not dental or medical advice.
Oscillating-rotating
Best for: App tracking and a case without paying for a screen
Sonic
Best for: Travellers who want one cable and a Sonicare
Brush + flosser
Best for: People who skip flossing and want it built into brushing
It tells you when you are pressing harder than the maker intends, by a light, a vibration or both. 24 of the 53 brushes here list one. It is a feedback feature, not a treatment, and makers do not publish the force at which theirs trips.
Modestly, on average. A 2014 Cochrane review of 56 trials found powered brushes reduced plaque and gum inflammation a little more than manual ones, and called the clinical importance unclear. The ADA says both kinds are effective at removing plaque.
Every specification explained, with the real numbers from the catalog behind each one.