How does one prevent needing an implant for a front tooth?

After reviewing x-rays my dentist told me that a front tooth has dies. She sent the x-rays to an endodontist and he said the tooth could not be save. My dentist referred me to someone else to investigate an implant. Why am I in this situation? I have a long history of regular dental appointments. What is the reason that dentists do not x-ray front teeth? I do not have any pain issues with the tooth. I notice a slight color variation between my two front teeth but it is not noticeable to anyone else.