It looks like your tooth is infected. This happens with the chipped tooth. when the tooth is chipped and the restoration is not done then slowly the tooth gets infected. The lump on the tooth is the sign of infection .It is the intraoral sinus. if you really want to save the tooth then you have to go for the root canal treatment of the tooth . After the root canal treatment the tooth is restored with the crown. For more info on root canal treatment you can visit the following link...www.identalhub.com/article_why-is-root-canal-treatment-rct-required-299.aspx.
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