In early Christianity the pentacle represented the five wounds of Christ and the crown of thorns. It was hardly a symbol of evil then. The superstition that the pentacle is a symbol of evil is merely that, a superstition.
In modern Paganism the pentacle is a representation of the five Elements held within the circle of creation. Again, nothing evil about it. The inverted pentacle in traditional Wicca represents someone who has been initiated at the 2nd degree.
A pentagram is merely a five-pointed star. And that would include the star at the top of the Christmas tree.
I would say in this case that there is nothing at all wrong with either the pentagram or the pentacle. Evil being merely in the mind of the beholder.