Non-Aromatic-Very rich in Steranes (NAVS) naphthalan is a transparent, earth mineral oil prepared by a complex set of procedures of separations and refining, starting with a special oil that is used as the raw material for brown naphthalane, which has been successfully used in the treatment of psoriasis. In order to remove potentially mutagenic polycyclic aromatic hydrocarbons (PAHs), liquid chromatography was used. UV / VIS (ultra violet / visible light) spectrophotometry confirmed that PAHs were bellow detection threshold. Additionally, the precise distillation process has concentrated steranes, which are important bioactive constituents. Since steranes contain similar chemical structure as well-known bioactive substances, such as vitamin D3 and steroid hormones, the assumption is that NAVS is effective in the treatment of oral diseases which have immune genesis such as OLP and RAS.