Tongue coating: its characteristics and role in intra-oral halitosis and general health-a review

Tongue coating (TC), a grayish-white deposit on the tongue, is the main cause of intra-oral halitosis (IOH), a socially unacceptable condition. This review covers the general features of TC, including its formation and the factors that influence it. Volatile sulfur compounds (VSCs) are the principal elements of IOH, and TC and periodontal diseases are the two main sources of VSCs. This review covers the relationship between VSCs, TC, and periodontal disease. We comprehensively discuss the methods employed to quantify TC, its microbial composition, its influence on general health and its importance in general medicine.