Is my 55 gallon tank unsafe if it has no bridge?

i just bought a 55 gallon fish tank. i was recently told that if a 55 gallon tank doesnt have a plastic bridge on the top holding both panes of gl together that the tank is unsafe to hold water. my tank does not have this bridge on top but i also noticed that the gl on it are thicker than all other 55 gallon tanks ive seen. is it safe to use this tank? i havent set it up yet.