Hi, Bad breath could be because of local and systemic causes. Local causes could be due to calculus (yellow scales)deposits on the tooth which comes with improper hygiene. Systemic causes are due to any gut infections. Once calculus is formed it is difficult to get away with brushing alone. Professional Scaling (teeth cleaning) has to be done. Stains also will get away with scaling. Try to quit deliberate habits like smoking, pan chewing etc which are the prime cause for tooth stains. Fluorosis stains need teeth bleaching techniques.