Help! I've dented my phone battery

While fixing my phone , I accidentally made a small dent at the top-right corner of the battery. Its almost unnoticeable. After multiple streak of bad luck I decided to let a professional fix it.

He said that the battery started to expand(it is said because I played while charging[which is true]).

I’m a bit paranoid so , did the small dent cause it to expand? and/or is it safe to use for at least 3 month?