Fluorosis has different grades and the treatment depends upon the present condition of the teeth, which is best determined by a proper clinical examination. The treatment can vary from bleaching to laminates or veneers or Zirconia Crowns. So the cost will also depend upon the treatment modality which will be best explained to you by the dentist who performs a proper clinical examination. Alternatively, you can post your clinical picture on Practo for an online consultation with the specialist for an opinion based on a clinical picture of your teeth. And because it is an aesthetic treatment, which is based on camouflage, and treats the discoloration and the gaps between your teeth, it does not damage your teeth in any way to cause any side effects. Regards.