JANUARY 8, 2002 CHEMICAL WEEKLY 165 Actives in Oral Care Products SITARAM DIXIT Applications Manager (Fragrances), Bush Boake Allen India Ltd., Mumbai. The growth of oral hygiene products is not only due to the income and educational levels of the user but also due to the realisation that tooth loss is not dependent on the age of the individual. This consumer awareness propels a person into buying a premium priced product offering therapeutic or value-added benefits. Tooth decay and dental caries results from the continuous occurrence of plaque, a sticky film of bacteria that constantly forms in the mouth together with their decomposition products and food residues. Plaque is believed to consist of salivary proteins, modified by bacterial enzymes, polysaccharides, lipids, minerals like calcium and phosphorous, water, etc. It is typical for an individual and varies widely at different parts of the oral cavity. Plaque adheres to teeth and the areas between them and, if not removed, calcifies or mineralises to form a cement-like substance called tartar or calculus. Cal- culus comprises of 80% of inorganic material containing calcium, magnesium, phosphorous and other elements and the remaining 20% comprise of organic matter like, carbo- hydrate, protein, lipid and bacteria. Calculus hardens, staining teeth and makes them rough. It also provides a perfect place for bacteria to grow and proliferate. The bacteria present generate acidic metabolites lowering the mouth pH to 5.5, which causes an attack on the dental enamel. Such repeated attack breaks down the tooth enamel exposing the sensitive part of the tooth leading to rapid onset of dental caries. The formation of calculus also irritates the gums. Gums become red, swollen, or tender, and may bleed on brushing causing gingivitis to eventually culminate in periodontal diseases. Ultrastructural studies shows that many types of microbes are responsible and become associated with periodontal tissues. The microbes present in the interface exert a great importance in the destructive actions that are associated in periodontitis. Periodontal disease is caused by specific micro- organisms not regularly found in a healthy mouth and for which the oral cavity is not a primary habitat. Those organisms that are indigenous or belong to the resident flora do not normally cause oral disease. Only those organisms that are extraneous under circumstances of reduced host resistance or due to overgrowth, cause disease and in such a situation, anti-infective therapy becomes necessary. Oral diseases cause tooth loss and pain, bad odour causes embarrassment in social circles, loose teeth interferes with speech and in some cases spread infection to other areas of the mouth and body. Regular and proper brushing helps prevent tartar formation, but once formed it can only be removed by a professional dentist by mechanical cleaning, either to prevent or to delay the onset of periodontal disease. Dental treatment is labour intensive and relatively expensive, causing discomfort. To prevent plaque associated diseases; plaque formed must be continuously removed. Simple brushing is only partially successful in this respect. To control oral diseases, conventional method still involves mechanical removal of plaque and calculus. A complimentary approach nowadays used is the application of chemical agents that would alter the oral environment and prevent the growth of putative pathogens. Chemical plaque control agents are based to counter the potential deficiencies of mechanical cleaning. The first scientific report concerning the use of chemical agents dates back to more than three hundred years before. In 1683 Mr. Van Leeuwenhock A., advocated the use of vinegar as a mouth rinse as it exhibited the property of killing bacterial micro-organisms. The most important aim of oral care is to reduce personal and social handicaps that become associated with oral diseases that an individual develops due to improper care of their dentition. Taking good and proper care of the natural dentition will not only increase the longevity, but will also improve the public status and so its function. Decades of detailed scientific research carried out at various dental research institutes, industrial laboratories and dental colleges and hospitals has helped to understand the varied functions affecting oral health, proving the old saying that a clean tooth never aches. Today chemical agents can be an antimicrobial or an anti- metabolic or others that are incorporated in oral care products for therapeutic benefits. Fluorides, chlorhexidine, zinc citrate, triclosan, antibiotics, enzymes, inorganic salts, etc., are used as chemical therapeutic agents in various oral care products. Chemotherapeutic agents incorporated into oral care products with claims for being effective in protecting oral health are termed as actives. They may be anticaries agents, agents affecting oral accumulation, agents that are capable of desensitising sensitive teeth or even those that prevent oral malodour. Fluorides and antimicrobials represent the largest category for which detailed studies have been conducted in various research institutions. These, when present even in low recom- mended levels, can selectively suppress certain micro-