burn is permanent so the tips of those leaves will not repair themselves. All you can do is prevent further burn. if you notice its spreading then flush from top to bottom out the drain holes with fresh water. It doesnt have to be too much you are just removing any build up of salt in the soil and I consider fertilizer a salt just like us we need salt but not too much or too little or it has a negative impact.
once the balance is back then future leaves will be completely healthy and if thats all the damage you have to those leaves they will be healthy too just damaged on the tips.