###Human: Why are there gap and sensitivity in teeth even after filling? ###Assistant: Hi. Your case has become a bit complicated. It would have not gone this bad if the filling of the adjacent tooth would have been done before taking size for the cap, then the gap would have adjusted and you would not be having any food sticking complaint. But do not worry, there is an end to every pain and suffering. You might have to go for these stages of treatment now. First of all, an X-ray of the adjacent tooth that is feeling sensitive should be taken and assessed. The following could be the treatment options you could have. If there is some internal carious activity detected that is causing sensitivity and has not touched the pulp or root of the tooth, then again you have to go for deep filling with some regenerative dressing in the deeper part of the cavity that may regenerate the tissues above the root, reduces sensitivity and inhibits the further carious activity. If there is some carious activity that has touched the pulp of tooth then you would be going for root canal treatment and capping as done before. Then cap will be placed and it will fix your gap. You can have an option of capping at sensitive tooth after deep filling if caries has not reached pulp. Cap size will be adjusted to fill the gap and you will be relieved. It would be great if you can provide me with some of your clinical pictures of teeth and X-ray of both RCT treated and sensitive tooth. Then I could suggest better which option will suit you.