Is a root canal necessary if a dentist takes an x-rays discovers a swollen nerve and spot but the patient has absolutely no pain?

Find you another dentist; have that one transfer your records over to him/her from your old dentist. Then have the new dentist check your mouth out. This would be a second opinion. If it turns out the same way, then go back to your old dentist, or if not, then keep the new one. Some of these, just like doctors can't be trusted- they try to make a buck anywhere they turn.