Black or brown spots between the teeth are a symptom of gum disease, reports Healthy Smiles. Gum disease starts as gingivitis and, if not treated, develops into periodontitis; however, black spots are a sign of periodontitis.
Periodontal disease rarely presents any pain to the individual and may go unnoticed until it begins to breakdown bone, which in turn causes the loosening of teeth, explains Healthy Smiles. The primary cause of gum disease is bacteria, which deposits plaque on the teeth. If the plaque is not brushed off, it may harden to form tartar, which is where the bacteria harbor to cause the disease.
Nonsurgical treatment options include scaling, root planing and antibiotics, notes Mayo Clinic. However, if the disease is advanced, surgical options such as flap surgery, soft tissue grafts, bone grafting, guided tissue regeneration or enamel matrix derivative application may be considered.