Hi.. Can understand your concern.. As per your complain in case if you have a deeply decayed tooth it can lead to infection reaching the region below the root tips of the tooth causing infection and pus formation in that region which accumulates in the soft tissues causing abscess formation.. When you take antibiotics the infection reduces to some extent and the abscess seems to subside but when the antibiotics are stopped the infection recurs and cause recurrence of abscess.. Dark colour and smell of urine can be due to discolouration caused by the edible dye colour present in medicines.. For permanent relief you should consult a dentist and get evaluated and in case the tooth can be saved Root canal treatment followed by antibiotics and painkillers can relieve or else extraction can be done.. Burning during urination are symptoms of urinary tract infection and your husband getting it from you is possible in case of your oral communication with his private part but the chances are less but cant be neglected.. He can consult a Urologist and get a urine culture done to rule out if there is any infection and get treated accordingly.. Hope this information helps.. If you find the answer helpful please write a positive review and click on find this answer helpful as a token of appreciation.. Thanks and regards.. Dr.Honey Nandwani Arora..