hello, well it looks like you have got a deep decayed tooth, involving the pulp or nerves of the tooth. it will be difficult to advice without seeing the case and radiograph of the involved tooth. if the decay is deep but not extensive . that means the crown portion is intact then we can try saving it, but everything depends on the clinical and radiological findings. it is advised to save the tooth if conditions are favourable, as it is tooth which helps you in chewing the food.

It means there is cavity in teeth Which reach to pulp that’s why causing pain Treatment depends on extend of decay It can either be treated by RCT or by extraction Visit nearby dentist so he or she can take X-ray n diagnose accurately