Is it normal for there to be a gap between my dental crown and gum? (photos)

The bump is most likely not directly related to the novacaine shot itself. You might've bitten your lips while you were numb or it can be unrelated. You can check with your dentist later.

The temporary crown probably has an "open margin" where food and bacterial is getting in. Your dentist can fix that or you can just wait for the permanent crown. 

I would not recommend crowning #25 in most situations. The tooth is simply too small to crown effectively without removing most of the tooth structure. This is especially true in an apicoectomy situation, as the tooth is mostly left intacted after the procedure. 

You can go with the crown for space closure. but the best option is space closure by orthodontic treatment. Crowns sometimes may look big and bulky.

Teeth naturally move due to position, bite and if a patient clenches or grinds. You may want to have your dental provider take X-rays to confirm the crowns are seated completed and that there is no gap between the crown and the tooth. Also, your dental provider can confirm that there is no...

When working in the back of the mouth, dentists usually numb you up by doing a lower jaw block. In doing so,  your lower jaw nerve (mandibular branch of your Cranial Nerve 5, not Facial nerve which is Cranial Nerve 7) may be disturbed or injured. If that nerve was injured during...