Hello ma'm, Proper  in office consultation with dentist /oral surgeon for further clinical examination & treatment accordingly is important. Although the wisdom tooth is broken down due to caries & is asymptomatic I. e have no pain or swelling ; but  requires in person visit to the know the remaining status of the tooth inside the jaw which might be having infected roots with periapical lesion.

Firstly clinical and radiographical examination is necessary for proper diagnosis and treatment planning. If your wisdom tooth is Impacted than It needs to be extracted. If it is fully erupted and have sufficient tooth structure than It can be saved if you want. Though you don't feel any pain treatment is required because in future it can cause infection and sometime swelling.

Your tooth needs to be evaluated clinically and x ray needs to be taken for proper management of your problem.  Tooth filling, root canal treatment or extraction are the various treatment options. You need to visit an oral and maxillofacial surgeon for the same. Hope it helps

Depending on the radiographic and clinical findings, a proper diagnosis can be made. If the tooth is fully erupted and there is enough space and tooth structure remaining, the dentist may try to save the tooth or otherwise, get it extracted.