Encoding Php to DB

i got some problems with the codification on my db. Db and table are set with utf8_general_ci, and all php web page have some header with this encoding. From FORM i've to insert something, that is perfectly shown on web page, but on db figures like : à weà rewà fà dsà fewÃ

After db connection i've made some:

$connection->set_charset("utf8_general_ci");

Someone can help me with this? Thank you everyone!!