1700654152_8. Diet and caries process.pdf

DIET AND CARIES PROCESS DENA MOHAMED CPHQ, MPH, MFDRCSI, BDS Role of diet 01 Role of saliva 02 Caries mechanism 03 Dietary factors and dental caries 04 OBJECTIVES Protective...

DIET AND CARIES PROCESS DENA MOHAMED CPHQ, MPH, MFDRCSI, BDS Role of diet 01 Role of saliva 02 Caries mechanism 03 Dietary factors and dental caries 04 OBJECTIVES Protective factors and dental caries 05 Role of diet Diet plays central role in development of dental caries Dietary sugars are the major dietary factor affecting dental caries prevalence and progression. Sucrose is the most cariogenic sugar because: Its metabolism produce acid MS (Mutans streptococci) utilize this sugar to produce the extracellular polysaccharide glucan. Glucan polymers are believed to enable MS to adhere firmly to teeth Role of diet Caries is associated with in the proportions of acidogenic and acid tolerant bacteria, especially Streptococcus mutans. in bacteria species associated with enamel health Role of diet Cariogenic bacteria metabolize dietary sugars to acid creating locally a low pH. High frequency of CHO intake with regular pH drops favors the proliferation of streptococcus mutans. As the pH falls to the critical pH, below 5.4, demineralization of inorganic portion of the tooth (calcium and phosphate) occurs. Role of diet when the rate of demineralization exceeds the rate of remineralization, an initial carious lesion can develop. Role of diet The critical pH value for demineralization is in the range of 5.2 to 5.5. conversely, tooth remineralization can occur of the pH is high due to: 1. Lack of substrate for bacterial metabolism 2. Low percentage of cariogenic bacteria in plaque 3. Elevated secretion of saliva 4. Strong buffering capacity of saliva 5. Presence of inorganic ions in saliva 6. Fluoride 7. Rapid food clearance time Role of saliva Saliva promotes remineralization, because of calcium and phosphate content If the pH of the mouth remains high for enough time, complete remineralization may occur. The rate of demineralization is affected by the concentration of hydrogen and fluoride ions. Caries mechanism Acidogenic bacteria ferment CHO producing organic acid, including lactic, formic, acetic, and propionic These acids diffuse into enamel, dentine, or cementum, and partially dissolve the carbonated hydroxyapatite mineral crystals Caries mechanism If the process continues, the minerals (calcium and phosphate) diffuse out of the tooth leading to cavitation Demineralization can be reversed by calcium and phosphate, together with fluoride diffusing into the tooth and depositing a new layer on the crystal remnants in the non-cavitated lesion Caries mechanism This new mineral crystal layer is more resistant to acid compared with original hydroxyapatite mineral The process of demineralization and remineralization occurs numerous times daily Dietary factor and dental caries Frequency and amount of ingestion of dietary sugars and dental caries: Both the frequency of consumption and total amount of sugars are important in the etiology of caries because frequency of intake and amount of sugars ingested are closely related Dental caries increases with increasing frequency of intake of sugars, even when the absolute intake of sugars was the same Dietary factor and dental caries Food form The form of CHO is directly influencing the duration of exposure and retention of the food on the teeth Liquid sugars have limited contact time or adherence to tooth surface. While long-lasting sources of sugars such as chocolate and hard candies have extended exposure time Dietary factor and dental caries Oral clearance The retentive properties of the food such as cookies and chips increase the potential the starch has to breakdown into sugars and contribute to the caries process Clearance time may be prolonged by retentive factors in the dentition such as cavities, poor filling, dental prosthesis, low salivary rate, or high viscosity of saliva Practical way to speed up carbohydrate’s clearance is tooth brushing immediately after meal Mouth rinsing by water has little effect. Dietary factor and dental caries Acid content The acidity of the foods can precipitate erosion, and it depends on the ability of the oral buffering system to neutralize the food. Dietary factor and dental caries Sugar alcohol-based products Sugar-free gums are tooth-friendly polyols include sorbitol, xylitol, mannitol, erythritol, and isomalt. They have the following action: 1. Stimulate saliva 2. Increase the clearance of sugars and other fermentable CHO 3. Increase the buffering capacity Carbohydrate and dental caries CHO are classified into, monosaccharide, disaccharides, and polysaccharides Monosaccharide and disaccharides are metabolized into acids by bacteria Polysaccharide (starch) is metabolized first by salivary amylase into maltose and glucose, then they become available for metabolism by bacteria. So, starch is less important in causing dental caries Fruits and dental caries Fresh fruits are less cariogenic Dried fruits are more cariogenic because: 1. The drying process break the cellular structure of the fruit releasing free sugars 2. Longer oral clearance Protective factors and dental caries Cheese It is non-cariogenic and has anti-cariogenic properties as it: 1. Stimulate salivary secretion 2. Increase plaque calcium concentration 3. Adsorption of protein (casein) on the enamel surface Protective factors and dental caries Milk Contain lactose which may be classified as cariogenic, but is least cariogenic of dietary sugars. Milk also contains calcium, phosphorus and casein which inhibit caries. Evidence from animal experiments show that cow’s milk is not only non-cariogenic, but also has an anti-cariogenic effect. Protective factors and dental caries Fibrous foods Are mechanically stimulate salivary flow Protective factors and dental caries Fat Fats reduce cariogenicity of food Form protective barriers on the enamel Surround the carbohydrates make these less available and speed up their removal from the mouth Alters bacterial surfaces properties, and have antibacterial and antimicrobial properties Protective factors and dental caries Black tea Contains fluoride, it increases plaque fluoride concentration and reduce the cariogenicity of a sugar rich diet Effect of fluoride on sugar-caries relationship Fluoride has a protective effect against dental caries as it: 1. Increase resistance of teeth to demineralization 2. Increase the speed of remineralization 3. Affects plaque by inhibiting bacterial metabolism of sugars Topical fluoride application reduces caries in children by 20 - 40 % Sugar substitutes 1. Non-caloric sweeteners Intense sweet taste and contain no energy. Not metabolized to acids by microorganisms. Saccharin used in alternative food products without added sugar such as sweet drinks, biscuit, jams, drops for used in food, coffee, tea. Cyclamate is sold only as a drop. Aspartame is used in tablets, chewing-gum, beverages, and ice cream. Sugar substitutes 2. Caloric sweeteners are sugar alcohol Sorbitol is safe for teeth, and less cariogenic, they are used in medicine, toothpaste, food products, and sugar free chew-gums. Xylitol is non cariogenic, non-fermentable in plaque and saliva, and have antimicrobial effect, it is used in toothpaste, fluoride tablets, saliva substitutes. Lycasin has low cariogenicity, safe for teeth.  THANK YOU ! QUESTIONS