What Could Be Causing A Persistent Salty, Acidic Taste Behind My Upper Central Incisor For Four Years?

Hi,I have a constant salty acidic taste coming from the upper front tooth(central incisor) for almost four years. The salty acidic taste is coming behind the tooth gum.I went to dentist,periodontist,mouth pathology and ear,nose and throat specialist.The last two specialists have referred me to two different ct scans (2018 and 2021).There is no problem.In 2020 I have decided to extract the lateral incisor (there was a crown with root canal).Nothing change.Please help me.Thank you for your precious time!