Without a proper clinical examination, an accurate diagnosis cannot be made and a rational treatment plan cannot be suggested. Still a few things can be told to you. Do not delay the treatment till the tooth becomes symptomatic and you develop any pain in that. Mostly wisdom teeth are non-functional and instead of root canal treatment or fillings, extraction is the preferred treatment modality for a permanent solution to the problem. But if it is in functional occlusion, it can be filled by tooth coloured filling or can be root canal treated followed by a crown. Regards.