Mouth Ulcer are happened very frequently

Mouth ulcers can happen due to multiple reasons and there is no single "exact cause" of mouth ulcers. It will not be even practical to enumerate the entire causes of mouth ulcers especially those which are multiple and recurrent. A proper clinical examination and detailed history will be required to ascertain the exact cause of your mouth ulcers. Taking multivitamin supplements like B complex and Vitamin C can maintain the health and integrity of the oral tissues but do not sure the answers if they are present. No medication, for that matter, can treat mouth ulcers other than providing temporary symptomatic relief. If the ulcers are due to viral or fungal etiology then antiviral or antifungal medication do play a role in the healing. Changing your brush every two or three months is a good habit and you should continue doing that, something like regularly taking multivitamin supplements. Use of antiseptic mouthwash is which are based on generic composition of chlorhexidine can also improve the oral health if used regularly. Clean your tongue using your toothbrush only every time after you brush your teeth. Do not use metallic or plastic or wooden tongue cleaners because they do more harm than good. Regards.