Hi,
It sounds like you have 2 issues, one being the pain in your lower teeth and the other being gaps between your teeth after having a new crown made.
There could be several reasons for gaps appearing after a new crown is fitted. The crown could have the bite pressure distributed unevenly, causing tooth drifting. If all the biting contacts are concentrated only on one half of the crown, this can cause orthodontic tooth movement that may result in gaps or even changes in the way you bite.
Adjustment of the bite of the crown may be able to reverse or improve the situation if this is the case. However, trimming the crown surface may cause it to thin out or become perforated, requiring the crown be replaced.
Another significant cause of gaps appearing between the teeth is untreated gum disease (periodontitis) that has caused bone loss around the teeth. When the jawbone resorbs in the gum disease process, this reduces the amount of support and stability for the teeth resulting in drifting, spaces and uneven biting patterns emerging.
It may be possible to fill up gaps between the teeth using filling materials or even splinting loose teeth together, but these solutions tend to only be short term, unless the underlying cause of tooth drifting has been identified and managed.
